rn rnAorN pNd NCI cni mrrust
"r"nUdrue DAr Fiele nncrt KHoA
irl{Ai.\ ei-l6c uurqc - ro urir't IHUC
DA! r-rsc nr"ro'c
ilril
, lt | | \ i-
Ii
L\-
e
rl \
| L-l
I\'I ,I - \r
-L\-l i-_L t_ \_i
lu
tli
tl,__
i-.
i
L
L
LL
D4r Hec qudc cre rHANn pnd HO cni MrNH
rnrJduc DAr Hec sAcH KHoA
Phan Qudc Dffng - Td Hrlu Phric
TRUYETI DOTIG DTETI
a
(Tdi
l^''r^.
bd,n
ldn tht
ba)
NIIA XUAT BAN DAI HQC QUOC GIA
.2016
THANH PHd nd
Mqc Lvc
t ot Not oAu
Cluong
1
NHIJNG KHAI NIDU co BAN
1'1
n
H'
th6hg truydn d6ng diQn vd cdc phdn tfi - MQt so
dinh nghia
1.2 D6ng hoc crja hQ th6'ng dQng co _ t6i
1.3 H9 th6'ng b0 bidn ddi
_
9
dQng co
18
1.4 Di6u khidn t6'c dQ truydn dQng di6n
Bdi tap chrrong
T
20
1
22
Clutong 2
Drdu KHrdN roc oQ DONG cd MOr cHriu
25
2.1 Tdng quan
25
2.2 HC Mriy phrit - DQng co
2.3 Tdng quan
vt-\ hQ
38
thdng bQ chinh
lm
2.4 HC thdng bQ chinh hnr
_
d6ng co
2.5 HC thdng bQ chinh
_
dQng co c6
lur
_
d6ng co DC
40
45
dio chidu
51
2.6 86 bi6'n ddi xung dp
2.7 HC thdng b9 chopper
56
_
dQng co DC d chd rlO clQng co
2.8 HC thOng b0 chopper - tlOng co DC d chd
d0 hlm trii sinh
60
6.3
2'9 Hc thdng b6 chopper - dong co DC ldm vi6c
hoat dQng d nhi6u
g6c phdn trr
66
Bdi tap chrrong 2
76
Chuong 3
Driu KHrfN voNc r<ix oONc
cO
Dc
e5
3.1 So dd khdi tdng qurit hQ thdng didu khidn
vbng
3.2 Hdm tiuydn cric phAn tr?
kin
3.3 Kh6o srit h6 thdng didu khidn vbng
DC
kin d6ng
co
clQng co
DC
95
96
101
(ilrdntH'l
t)()NC o(t Kr{oNG pdNC eo - oriu KHI6N
ril IONG DdNc
e0
4,I l)rip rhrg ctia dQng co kh6ng
r6c o0 DoNG cd
116
ddng b0
4 l.t Klrrii <lQng vA hdm d6ng co kh6ng dOng b0
4.lt l)iOu khidn t6'c
dO dQng co khOng dOng b0
724
130
131
4.4 l)idu khidn diQn dP stator
4.1-,
116
l)i0u khidn tAu sd dOng co kh6ng ddng bQ vdi bQ bidn tAn
136
rrgtriin dP
4.(i l)idu l<lridn tAn so dQng co kh6ng dong bQ vdi bO bidn tdn
t43
rtgtrdrt ddrlg
4.7 Srr
(le) khOi hQ
th6'ngbO bien tAn - dQng co
4.ft l)i6Lr l<hidn c6ng sudt truot dQng cd r6to dAy qudn
IIc rli0u kliidn xung
4.10 ll8 riOi tAng tinh
4.9
diQn
trd rdto
L49
L57
1,57
165
t76
BAi tqp chuong 4
Clltong 5
Driu NHIdN;vscTd
DONG
co KHoNc odNc e0
5.1 MO hinh ttQng ctia d0ng cd kh6ng d6ng
bQ
L94
L94
b.2 Nguy6n ly di61 khi€in dinh hudng ttra theo trgdng vd ctic so do
210
didu khidn dinh hrrdng theo v6cto tit thdng r6to
233
5i3 Nguy6n lf didu khidn trrrc tidp mdmen
,
6
Driu xnrfN t6c
Cltuong
oO DONG cd
6.1 M6 hinh cfia dOng co ctdng
odxc e0
238
238
bO
6.2 Trang thrii v4n hdnh xric l4P
247
0.3 Didu khidn vAn tdc bbng crich thay ddi tdn sd
6.4 HC truydn dQng ddng co ddng b0 PM-SM vh RSM
248
6.5 He truy6n tlQng d6ng co dOng bO
til trd
257
276
t dt rvot oAu
Ngdy ruay, cdc hA buyAn d6ng diAn cltiant ntot tti tri quan trong
trong sd,n xu(It, giao th6ng uQn trii, ddn dung, u.u. (J6c tinh c6 khocing
50Vo d.iAn nd.ng sdn xudt rq. duoc ilAu fuu bdi c<tc hA tuuydn d,6ng diAn.
Sq phdt tridn cdc hC thdng truydn d6ng diAn d,i tlteo htrdng nAng
cqo hiau qwi kinlt td ud. d6 tin cdy bdng crich tidp tuc h.od.n thian d6ng
co, thidt bi, bQ bidn diii c6ig sudt bcin. ddn, ha thdng d,idu hlridn d,ang
analog ud dang sd.
su tidn bQ ht thudt nhanh ch6ng trong cdc ldruh uuc hj thudt dian
ud dian tt, c6ng nglta cltd tao bcin ddn c6ng sudt l6n, hy tltud.t ui xt ljt
ud. DSP dd. d6n ddn nhtTng thay ddi l6n trong tjt thuydt ud tng d,ung cila
buyAn d6ng di€n.
Do cdc chttc nd,ng duoc dcint trd,ch bdi cdc lta truyin d.6ng trong ctic
co cdu chdp hdnh. ngay cdng duoc ntd r6ng ud gia tdng ti,nh phtc tap,
uiAc dd.o tao cd,c lej stt chuyAn m6n c6 lelxi ndng thidt kd, udn hd.nh, hiAu
chinlt ua lelrui thric cac hA buydn dong diAn l,a t,An dA cdn tlLidt.
TRUYfrN DQNG DIIN (TDD) duoc bian soan nhdm ntuc d,ictt cung
cdp cho sinh ui€n nhrtng hidn thttc co bcin dcr. nau tan. Td.i li€u drtoc
soan d4ta tlteo dd cuong rn6n h,oc "Truyd.n d6ng diAn" cl"Lo sinh ui\n
clwy|n ngdnlt Kj tltudt diAn, Khoa DiAn - DiAn ftT, Trudng Doi hoc
Bdclt kltoa - Dqi h.oc Qudc gia TP HCM.
Dd giilp sinh. uiAn dC tidp thu nfit crich c6 hQ thdng, trong ttlng
chuong chilng t6i ddu cd dua ra cric ui du ntinh ltoa ud bdi tap tu girii
duoc, cdc ui du ud bdi tQp nfi phdng ffAn Matlab I Sintulinh dA' ntinh
lroa ddc tinlt. d6ng.
TRUYBN DQNG DIEN g6nt co 6 cltuortg:
Cltuong 7, 5, 6 do PGS.TS Phan Qudc Dung biAru soan.
Cltuong 2, 3, 4 do TltS T6 Hrtu Plttic biAn soan
Chting t6i xin cltd,n thd,nh cdnt on PGS. ?S Ngttydn HtZu Phtic (86
m6n Thidt bi diQn), PGS.?S Ngu,ydn Van Nhd (86 nfin Cung cdp d.ian)
Chrlng t'i rdt nwng ntudn nhd,n duqc cd.c g6p ! xdy dqng cfia cdc
il6ng nghi,p ud qu! dQc gid dt! cu,tJn sdch. ngd.y cd.ng hod.n tldQn lton.
.MOi gdp
!
rin
gti
ud
dia clt'i:
BQ mOn Cung edp diQn, Khoa Di€rr
Trrrdng Dqi hgc Bdch khoa
-
DiQn ttl,
- DHQG TP Hd Chi Minh,
Thudng 4iet, Q'10, TP HCM'
Tel. 0E 8056862,
zAE
L!
Email : Doduns@hcm.vnn'vn
TP H6 Chi Minh, thd'ng 5 nd.m 2016
Cd.c td.c
giti
chtuns
I
NHIINc KHAI NGM cd eAN
Chuong ndy sE trinh biy mqt s6'kh:ii ni6m co bAn v6 cr{c hC thdng
truydn d6ng di6n, dac biet ld cric hQ th6'ng truydn d6ng di6n sfi dung c6c
bQ bidn ddi bdn ddn cdng suat.
1.1 nE rnOnc TRUyEN 00Nc DIEN vA cAc pnAn
r0 -
rvlOr s0'
olNH NGHIA
li m6t h6 th6'ng mriy m6c dudc thiCl
kd vdi nhiQm vu bidn tldi co ndng thdnh diQn ning vd bao gdm cri kh6
ndng didu khidn bXng diQn cho quzi trinh bi6n cldi niy. C:ic hQ thdng
truydn dQng diQn drroc srl dung rQng r6i trong cric thidt bi hodc d6y
chuydn sin xudt c6ng nghiQp, trong giao th6ng v{n tdi, trong cric thidt
bi tli€n ddn dgng,...
LIdc tinh khoang 50vo diQn nd.ng s6n xudt ra duoc ti6u thu bdi cric
hQ truy6n dQng diQn.
HQ truydn d6ng diQn c6 thd hoat dQng vdi tdc d6 kh6ng ddi hodc vdi
tdc d0 thay ddi duoc (he didu t6'c). HiQn nay, khoring 7S-8OVo c:ic hQ
truydn dQng dign ld loai tdc d0 kh6ng ddi; vdi cdc hQ thdng ndy, tdc dQ
hoat dQng cria dQng co hdu nhu kh6ng cdn didu khidn trir c:ic quri trinh
khdi rlQngvd hdm. Phdn cdn lai, chidm khoring 2O-2EVo,ld c6c hQ thdng
c6 thd di6u chlnh drroc tdc d0 dOnS co tld phdi hop duoc ddc tinh dQng co
vi ddc tinh tdi yOu cdu. Vdi srr ph6t tridn manh m6 cria ki thu{t bdn
ddn cOng sudt ldn vd ki thu4t vi xrft lf hiQn nay, c6c h€ didu t6'c sfi dung
ki thu{t diQn tfi ngiy cdng drroc sfi dung rdng rdi vA li c6ng cu kh6ng
thd thidu drroc trong qud trinh tU dong h6a sdn xudt. Do d6, nQi dung
MQt h9 th6'ng truydn dQng diQn
tI-'.'A-
CHUONG
Srr dd
klr0i t,rrrg qudt cii^
1
th6ng truydn d6ng di6n drroc m6 ta
hodn thdnh
*Qt' chfu
di'h,
vi
du:
mdy
c6ng
cu, mrry nghidn gidy, cdu
'n'g 'h01,
[ruc,.'.'l'ho'g r,hrrd'g,
t,rii duoc bidu di6n qua qua'h6 girra tdc dQ vd
rrrOrlt('n ciia n6.
t,r0rr
rrrQt hQ
hi'h l.r. 'frii ri <kly rA rrrQt co cau mziy drioc thidt kddd
B0 bien ddi
Kh6i di6u khidn
Hinh
hhdi tdng qudt hA hdng truy\n d,6ng diAn
Quan h6 girra toc dd vd mOmen cria t6i duoc goi rd dqc finh co crta tdi.
Quan hQ gitra t6c d6 vd m6men cria d6ng co duoc goi ld ddc tinh co
cila dQng
1-1: S<r drj
co.
Hinh 1.2: Cdc dang dec tinh co crtq d,6ng co
a) DQng co DC ktch ti d6c ldp; b) DQng co kh6ng d,6ng
b6
c) DQng co d6ng b6
Ngoai ra, ta cdn dinh nghia itec tinh co dian rd quan hQ gita
t6'c clQ
vA dbng di6n cria dQng co.
Ta c6 ddc tinh co tu nhion cria d6ng co n6t dQng co drroc
van hdnh
chd d0 dinh md,c, u{ du: ddc tinh co trr nhi6n cria dOng co
kh6no
&
NHTJNG KHAr NIEM
co
eA^t
Dd lqta chgn mQt h€ th6'ng truydn dQng diQn thich hop cho mQt r?ng
dung nio d6, trudc ti6n d{c tinh co cria t6i phdi drroc kh6o srit k} ludng.
Tidp tldn, dQng co tlrrgc lrr. a chon cho hQ thdng tr6n co sd ddm bAo th6a
m5n cdc y6u cAu vd m6men vi tdc dQ cfia t6i, ddng thdi ddng diQn dQng
cd kh6ng vugt qud cdc gp6i hgn cho ph6p cria d6ng co vA cria ngudn.
Th6ng thudng, dic tinh co tU nhi6n cfia tlQng co kh6ng thd th6a mdn c6c
y6u cAu cria t6i. Vi v4y, mQt bQ bidn ttdi c6ng sudt dtng brin ddn (trl day
s6 duoc goi tdt le bQ bidn ddi, ho4c vidt tdt la BBD) duoc sfr dung vd ddt
gita clQng co vd ngudn nhu hinh 1.1.
B0 bidn ddi bao gdm mach dQng luc vA khdi ttidu khidn nhrr hinh
1.1. B0 bidn tldi gifr nhiQm vu tlidu khidn ddng cdng sudt tt ngu6n ddn
dQng co sao cho tl{c tfnh co vd rl{c tinh tdc d0 ddug dign cfia dQng co
tudng hgp vdi y6u cdu cria tdi. Khdi didu khidn cfia bQ bidn ddi c6 thd sfi
dqng ki thuft mach trJdng tr/, m4ch sd ho4c kf thu4t vi xfr lf vd hoat
dQng vd'i mrfc diQn dp vd c6ng sudt thdp hon nhidu so v6i mrlc diQn dp
cfia mach dQng lu. c trong b0 bidn ddi. \n lf do an toin vh trrinh nhi6u
phdt sinh do viQc d6ng ngdt cdc linh kiQn cdng sudt, m4ch dQng luc vd
m4ch tlidu khidn thudng c6ch ly v6 dign. Chi tidt vd ho4t dQng cria cdc
b0 bidn ddi sfi dung b6n ddn c6ng sudt xin tham kh6o th6m trong c6c tdi
liQu vd diQn trt c6ng sudt nhrr [9], [12].
ViQc do vd h6i ti6'p mQt sd thOng sd cria hQ thdng rrhrr ddng qua bQ
bidn ddi, t6'c d0, g6c quay cria dQng cd.. dudc thrrc hiQn khi c6 y6u cdu vd
clidu khidn vdng kin ho{c b6o vC hC thdng. Cdc tin hiQu hdi tidp tlrroc
thrrc hiQn qua mach hdi tidp vd thrrdng srl dr.rng pdc cim bidn thich hop
tld cdch ly gif,a mach dQng lu. c vd'mach cliCu khidn cria h9 thdng.
1.2 D0Nc Hgc c0A nF rndnc DONG cd - TAI
trinh m6men cd bin
Chuydn dQng cria dQng
1.2.1 Phrrdlrg
tn'
thudng li chuydn dQng quay. Chu/dn ,H
.
dQng cfia tdi c6 thd le chuydn tlQng
quay ho{c chuydn dQng tinh tidn.
Htnh 7,3: So d6 tttong duong
Ngoii ra, tAi c6 thd cdu thAnh tt
hQ thfing dQng co - td;i
nhidu bQ ph{n, tdc dQ vd chuydn
dQng cria chring c6 thd khdc nhau. Dd thu{n tiQn kh6o sdt, thudng quy
ddi tai cria tlQng co vd truc dQng co nhu hinh 1.3, trong d6:
CHUONG I
t0
- tdc d0 g6c cfra dQng cd, rad./s; M - mOmen do dgng co sinh ra' Nm;
M" - m6men cin quy ddi vd truc dQng co, Nm'
cd dang:
Phrrong trinh dQng hoc cria hQ truydn dQng tdng qurit
<o
(1,1)
rr lul=turc*ue;
^,r - 'd'
d
chddQ xdc lQp,d.otld.t= 0
vi M = M"'Thdnh nnilnlff
gqi ld
qud d0'
mdmen dQng cfia hQ th6'ng vi chi xudt hign d ch6'd0
I<}liM > M",hQ thdng 6 ch6-dQ tnng tdc' Trong quri trinh ting tdc'
cbn cung cdp cil thdnh
dQng co kh6ng chi cung cdp mOmen drJa ra tdi md
mQt s6'
phdn mdmen dQng dd tao ra gia t6'c cho hQ truydn dQng' Trong
dQng xe
rlng dung c6 m0men qudn tinh J ldn, vi dU h€ thdng truydn
c6n khri nhil5u dd gia
diQn, mdmen dQng cd thddng phii ld'n hon m6men
he thdng y6u cdu
t6'c cua xe c6 thd cl4t tdi tri sd thich hop. Trong cdc
mrlc cao nhdt trong khi hQ
dd,p rl'ng nhanh, m6men dQng co cdn duy tri 6
nh6 nhdt.
thdng can duoc thidt kd sao cho m6men qurin tinh J d mrlc
qu6n tinh cria
I<hi M < M", hQ thdng d chd tlO gi6m tdc' Ndu m6men
(M < O) khd ldn dd duy
he thdng ldn, dQng co cAn sinh ra m6men hdm
tri gia tdc cria hQ thdng 6 gi6 tri thich hop. Trrong tu nhd khi tdng to'c,
dqng co
trong cric hQ thdng y6u cdu drip t1ng nhanh, m6men him do
duoc thidt kd'
sinh ra cdn duy tri d mrl,c cao nhdt trong khi hc thdng cdn
sao cho m6men qudn tinh d mritc nh6 nhdt'
thdi gian'
Trong mQt sd r1'ng dgng y6u cAu m6men tAi cao trong m6t
k] m6men trii
ngdn ciia chu ky l2rm viQc, trong khi phdn cdn lai cria chu
Ii llh6, m6men dQng c6 thd drroc sfi dung dti giim bdt cdng sudt cfia tlQng
C6c mdy niy chir
cd cdn l6p det. Vi d.q, x6t truydn dQng cho c6c m6y 6p'
gdn nhrl
y6u cAu m6men t6i ldn trong thdi gian 6p, ngodi ra m6men trii
co d6
dong
blng zero. Khi d6, mot brinh dh c6 thd drroc I6p dlt tr6n truc
tAngmdmenqudntinhcfiam6y'Trongkhodngthdigiankh6ngtai'hE
mOmen td
tdng tdc dd tich trfi dQng ndng' Trong kho6ng thdi gian 6p'
ldn lAm hQ thdng giAm tdc vd sinh ra m6men d'Qng Jdaldt'
m6men tai' I
dQng ndy cQng vdi m6men dQng co s6 cAn bhng vdi
phAi l6p dit
khdng dr)ng bdnh dd, dQng co vdi c6ng sudt cao hdn s6
dAm bAo m6men tAi cAn thidt.
NHtJNc XUet r,uEu
cO
11
aA^t
Vi dq r.r. MOt he thdng truydn dQng c6 m6men tdi quy ddi vd truc d0ng
cct Mc = 10Nm, m6men qudn tinh cria hQ thdng quy tldi vd truc dQng co
vd mdmen qu:in tinh cia dQng cd la J = 0,05kgm2.
Gie thidt cdn c6 quan hQ t6'c d0 c0a dQng cd o va thdi gian t nhu
hinh 1.4a. Hdy tinh quan hQ mdmen dQng co vd thdi gian cdn thidt dd
dat drroc srr bidn thi6n t6'c tlQ nhrr ydu cdu tr6n.
M
Q.
lN.ml
Irad/s]
100
80
60
40
20
b)
Hinh
a)
Quan hQ o{t) yOu
Gi:ii. Theo c6ng thfc (1.1):
-30
-60
-eo
0,2 0,4 0,6
7.4
cdu; b) Quan
hQ
M(t)
cd.n
thidt
M=M^*t49
"dt
Trong vtng bi6'n thi6n tuydn tinh cfia tdc dQ nhu tr6n hinh 1.4a, gia
tdc dQng co ld:
d'
dt
376'8 + 1gg4 rad/s2
=
=+ 0.2
Trong virng tdc dO dn dinh:
10
dt=
dt
=104,2Nm, udi
Nm,
= -84,2 Nm,
=LO
+
10
o
0</<0,2s
0,2<t < 0,8s
0,8 < f S 1s
thidt nhrr hinh 1.4b.
Luu f ld v6 m6t lf thuydt, su bidn thi6n dQt ngQt cria m6men M
theo thdi gian nhu hinh 1.4b Id kh6ng thd c6 ndu ngudn cung cdp c6
c6ng sudt hflu han nhrl trong thuc td thudng gap. Tuy nhi6n, y6u cdu
Quan hQ M(t) cdn
CHUONG
12
1
d6n c6ng sudt hiQn nay' tir cd nh6
dqng co
(1kW) den cd tru.g (vr\i trtlr. kW), cho ph6p tli6u khidn m6men
d6' tdc tlO tli6u
bidn thi6n tit 0 tl(rrr tli'h rnrlc tro'g vdng 1-5ms; trong
bidn ddi cdng
khidn mornon ci\rtg ilhilrrlr rreu c6ng suat dinh mtlc cia bo
Nhfng
bQ bic.rr <loi rlirng bdn
nh6.
1.2.2 Circ thirnh plr{in ciiu m6men c6n
phdn sau:
M6rncrr crin M, <.<i lhir <lrroc phan thdnh c6c thdnh
tr6n truc d6ng
7- M|rttatt rrrtr stil M,,,." sinh ra do ma srit hiQn diQn
sdt bao gdm m6men ma
co vh cdc bQ phdrr klrr'rc <:iia co cdu' M6men ma
cric b0 phan khdc quy cldi vd truc
sdLt tr6rr r,ruc rrQrrg (:(r vi\ *ra sdt tr6n
d6ng ctl.
gi6 ldm mrit dQng
2- M\rttert tlttt,tl 11it't M,,: Khi dOng co chuydn dQng'
tlQng ndy'
cct sr-r sirrlt rrt ttlolttt'tt clr<irlg lai chuydn
(quy tldi v6 truc tlQng co): Phg
iJ, M(trrtt,tt t'tt rlrt ytLt cdg ctia tdi Mt
thd clOc I{p holc phu thuQc
thu6<: viro lirrh clr:il <:tia tzii, vrr6rnen nay c6
tdc dQ, c5 thd bdt bidn
vdo tcrc tl6, hoiir: c6 ll-r0. ld rnQt hdm ndo d6 theo
cldi tiy theo chd tlQ hoat
hoac bi6n thiir' t,lrt,o t,hdi gian, vd c6 thd thay
d6ng cua ttii'
M..-"
'
[,t
-t-Mo
M."-n
u
B.t,l
m6men mq sdt
Hinh 7.5: Dd'c tinh m6men ma sdt ud' cdc thdnh phiin crta
tdc d0' M6men
Hinh 1.5 bidu di6n sU phq thuQc cfia mdmen ma s6t vho
phdn:
ma s6t Mn c6 thd phdn thenh c6c thdnh
"
NHANG
xuet NEU co eAN
13
- M6men ma sdt nhdt M^r.n.
Thinh phdn ma s6t tinh chi hiQn diQn khi h€ thdng thlng y6n ho6c
t6'c d0 rdt thdp, n6n s6 khdng duoc tfnh khi khAo sdt dQng hoc cria hQ.
ThAnh phdn ma srit khd ld hlng sd
Thdnh phdn ma s:it nhdt c6 thd bidu di6n theo tdc d0 nhrr sau:
M^-n=
f1
Q.2)
'1t1
trong d6: B - hQ sd ma sdt.
M6men quat gi6 tt 16 vdi binh phrrong t6'c dQ:
Mq=C'a2
trong d6: C - hing s0.
(1.3)
VAy mdmen ciln M" c6 thd bidu di6n nhu sau:
(1.4)
M" = M, + B. ro r M^r." + C.a2
Trong nhidu tnrdng hop, thAnh phdn (M-,- + C . cD2) << B. or. Dd don
"
giAn cho viQc gi6i tich, thdnh phdn (M^,." + C.itr21 c6 thd kd vAo m6men
cdn blng crich hi6u chinh hQ s6'ma sdt B cho phir hop.
Vd'i
gii
thi61 nhy, tU (1.1) suy ra:
A=I
ff
+
M, + Bct
(1.5)
tii
thddng g{p
Hinh 1.6 trinh bdy mQt sd dang dIc tinh co eda cdc tai thudng gep.
1.2.3 MQt
s6'dqng d{c tinh
c6ng sudt
thfP to" ao
L- cao
d)
e)
Mt
Hinh 7.6: D$c tf.nh mQt sd tdi thudng gqp
a) Quqt gi6 - Born ly td.m; b) Xe dipn (khing tinh tdc d6ng cia trong lttc)
CHUONG
t4
1.2.4 PhAn
1
logi m6men t6i
tAi c6 thd phAn thdnh hai dang tdng qudt:
1- M6men tAi c6 tfnh thd ndng
2- Mdmen tAi c6 tinh Phdn khdng
dqng
M6men tai c6 tfnh thd nang kh6ng ddi ddu khi chidu chuvdn
truc'
cdu
cfia
thay ddi. Cdc tAi phg thuQc trong h,tc nhrr co cdu ndng ha
tdi ndy'
thang mdy, ho{c tAi cfia c6c cd cdu n6n, k6o thuQc vio loai
tlQng vd
M6men tai c6 tinh phan kh:ing lu6n lu6n chdng lai chuydn
ra do ma sdt
thay ddi d6u khi chidu chuydn clQng thay ddi. Momen sinh
hoic do cdc cd ceu cdt got thuQc viro loai ndy'
1.2.6 KhAu cd khf quy ddi cfra truydn dOng di€n
Hinh 1.? m0 tA cdu trfc dQng hoc tdng qu6t cfia rnQt hQ truydn tlQng
Nhin chung,
mOmen
r,n
Jm, M,
r=1
c'r
Hinh
1.7: So
cI6
or,
Mlv, olv
d'6ng hoc co cd'u
truy|n
M
dQng diAn didn
J, Mt
hinh
mirnen ho(a lala ci'o bQ phQn ldtn aiQe ad trryc d'flng co
phdn co
Nguy6n t{c quy ddi la dua vdo sqr cdn bXng c6ng sudt trong
cria truydn dQng.
quay' ta c6:
N€u chuydn tlQng cria bQ phAn ldm viQc Id chuydn dQng
Tinh
qtt'y d.di
M1'A
hay:
=
M,=
Mw'Tt'v
n
M"u
= t'rl .,
4L
r.n
trong d6: Mr.v - mdmen phu t6i tr6n b0 ph{n ldm viQc;
ro1y - t'6c ctQ g6c b0 Ph6'in lim viQc;
n - hiQu sudt co cdu truYdn dOng;
o
(1.6)
(1.7)
NHANG
xuet NEU co aAN
15
N€u chuydn dQng cria b0 phQn ldm viQc ld chuydn d6ng thdng, ta c6:
(1.8)
(1.e)
hay:
trong
d,6:
Fyy - lqrc phr; trii tr6n b0 phQn lAm viQc;
p - brin kfnh quy tldi.lqrc phu
t6i vd truc
dQng co, e
= +-.
Tinh quy ddi m6men qudn tinh
ViQc quy aldi khdi lrrgng qudn tinh hodc mdmen qud.n tinh cria cric
khdu co khi vd truc dQng co c6 nghia ld thay thd cric khdu ndy blng m6t
mdmen qudn tinh J tr6n truc dQng co c6 gi6. tri tuong duong. Nguy6n t6c
quy ddi Id brio todn dQng nlng tfch lty cria h6 thdng, nghia ld:
Jt= ,^+*z',*.r-*'+
2
(1.10)
TU d6 suy ra:
J = J^.
ntn
>3
i=7 oi
+ \m,01
(
1.11)
j=l
trong d6: J^- mdmen qu6n tinh cria dQng co;
{ - m6men qudn tinh cria phdn tfi quay thri i;
m; - khdi lrrgng cria phdn tfi chuydn ddng tinh tidn thrl7;
i; - ti sd t6'c tlQ tit truc tlQng co tldn phdn tfi quay thrl i;
p; - bdn kinh quy ddi tdc 116 til phdn tfi chuydn ilQng tinh tidn
thrt' j ddn truc dQng co.
1.2.6
T!4ng thdi lim viQc cnia truyCn dQng diQn
Qud trinh bidn ddi ndng lrrong di6n-co trong hQ truydn
dOng dien
quy€l dinh trang thdi ldm viQc cria hQ.
Dd thu4n tiQn trong viQc kh6o s:lt cdc hQ thdng truydn dQng diQn 6
c:ic phdn sau, ta cdn quy rrdc chidu ctia tdc d0 vA m6men cfia dQng co.
Tdc d0 dQng co Ld duong ndu dQng cd quay theo chi6u thufn. Vdi hC
thdng chl hoat tl6ng theo m6t chidu, chidu thu4n dugc dinh nghia ld
chidu quay binh thudng iria hQ. Vdi h9 thdng c6 ddo chi6u, chidu thu{n
duoc chon tu do. Khi d6, tdc d0 tlQng co sE mang ddu Arn ndu quay theo
CHUANG
16
1
dQng co theo chidu thu{n. M6men dm sE gi6m tdc dQng co theo chidu
thu4n vd gia tdc dQng cd theo chidu nghich. C6ng sudl P"o do dQng co
sinh ra li tich coa m6men vd tdc do dong cd, c6 ddu tny thuoc chidu cria
hai tl4i luong ndy.
DQng co c6 thd lAm viQc 6 hai chd dQ: chd d0 dOng co vd'chd
hdm. Trong chd d0 tlQng cd, dQng co bi6'n diQn nlng thdnh co ndng
ra tAi. Nhu v$y, trong chd d0 dQng co, c6ng sudt dQng co c6 gi:i
drrong. Trong chd tlQ hdm, dQng co hoat tlQng nhu mQt m:ly phdt, bidn
ndng cria tei thAnh diQn
ndng - diQn nlng nAy c6 thd
tr6 vd ngudn ho{c ti€u thu
tr6n phdn tfi nAo tl6 cria
mach diQn trong hQ. C6ng
sudt dQng co c6 gi6
trong ch6'd0 ham.
.
tri
H6m
DQng cd
(Thu4n)
(Thuan)
tl
I
ill
IV
H6m
Dong cd
(nghich)
Am
(nghich)
Htnh 1.8 le
hC trgc
t6'c d0, chia m4t
phEng tga d0 thdnh bdn
phdn tu (quadrant).
mdmen -
Hinh 7.8: Cdc phd.n tu ldnx uiQc crta
thdng truydn dQng diAn
hQ
- Phdn tu I va III trfdng rlng vdi hoat dQng d chd tlQ clQng co
chi6u thu{n vd nghich.
- Phdn trr II va IV tuong rlng vdi chd d0 hflm-cria tlQng co til tra
thdi ho4t dQng theo chidu thuan vd nghich.
C6ng sudt diQn Pa duoc quy rJdc c6 gi6 trf dr-rong khi n6 c6
truydn tU ngudn ra tdi, vd c6 gid tri Am vdi chidu truydn ngrrdc lai.
d chd d0 h6m, tiy thuQc chidu truydn c6ng sudt diQn, ta c6
trang thdi hflm gdm: hdm t6i sinh, hdm nguoc vd hdrir il6ng ndng.
1- Hd.m tdi sinh:
Pa < O, P"o1 0,
ddng co bidn co n[ng thinh diQn ndng trd vd lrrdi.
2- Hdm nguoe:
Pa> 0, P"o10,
dQng co bidn co ndng thinh diQn ndng tldng thdi nh{n ning
Itr6i tliQn vd chuydn cdc ndng lrrgng ndy thdnh tdn thdt tr6n h6.
NHANG KHA: NIEM
co
aAN
77
3- Hdm d6ng ndng:
Pa= O, P"o( 0,
d6ng co bidn co ndng thanh diQn ndng vd chuydn ndng lrrong
tdn thdt tr6n
1.2.7
niy thinh
hQ.
Diiu kiQn dn dinh tinh cria truyCn dQng diQn
Theo (1.1), didm ldm vi6c cdn blng cfia h6 dat drroc khi m6men
ddng co bxng m6men tdi. Didm ldm vioc can bxng ndy c6 thd dn dinh
hoic kh6ng dn dinh.
Ggi mdmen dQng co, m6men tdi vd tdc clQ tlQng co tai alidm ldm vi6c
cAn bhng lAn lrrot ld. Mo, M"o vd. alo, ta c6:
vh
Mo=M"o
(r.12)
ff=o
Gi6 srl tai thdi didm f, he di chuydn kh6i vi tri cAn blng ndy vd c6c
gia sd tudng'rl'ng lA LM, AM" vd Ato. Nhu v4y tai thdi didm l, phrrong
trinh (1.1) trd thdnh:
,d(a"
dt
Thay (1.12) vdo (1.13), ta
Jry
dac
drJoc:
+ AIVI" -- aIvI = o
(1.14)
d vilng lAn cAn tlidm ldm vi6c, vdi m6t gia sO'Ao6 nh6, c6 thd xem
tinh co cfia dQng co vd cria tAi ld c6c dudng th&ng, do tl6:
^'= [#)^.
trong d6:
vA. cria
f
,a
Yl
da' {dM--!)
da
tdi quanh didm ldm
vd
ldn lrrot ld
AM"
=
(tk)^
dQ d6'c cria ddc
]o' =
DAy ld phuong trinh vi phdn bQc nhdt. Ndu
Ao16, gi6i phrrong trinh (1.16), ta c6:
Aor
Dd ttidm ldrn vi€c
tfnh co cria dQng
co
vi6c.
Thav (1.15) vdo (1.14) vA sdp xdp lai:
,d(La) *14M"_ _ dM
dt Ldo
da
Ao ld
(1.15)
.
e Aoo
"
Q
goi giri tri ban ddu cria
4v\
-+(+
J\ da d'I
#'dn dinh, AnT phrii tidn tdi.o khi
(1
(1.16)
(1.1?)
r -+ -. Dd
7
ti
CHUONG
(dM" dM\
| .__t>
dr)
Id,
1
(1.18)
u
Hinh 1.9 bidu
di6n
vi6c khric
cdc didm ldm
nhau cria mQt dQng cd
khdng ddng b0 vdi cric dIc
tfnh tii khric nhau. Didm
A vd C ld didm ldm vi6c
dn dinh, didm B ld didm
ldm viQc kh6ng dn dinh.
Luu y ld didm B vd C
nlm tr6n cing m6t phdn
d{c tinh co cria ddng co.
Nhrr vfy, srJ dn dinh cria
didm ldm viQc phu thuQc
kh6ng chl vdo ddc tinh dQng co, md cdn phu
thuQc
vio
ddc
tinh tdi.
1.a HE rndruc a0 sr6r'r odl - s0ruc cd
loqi bQ bi6n d.di
Bing 1.1 hgt kC cdc loai BBD vdi
7- Phd.n
chri'c ndng
vd rl'ng dung tudng f'ng
trong truy6n dQng diQn.
Bring
Loqi BBD
1
Chlnh lrru c6 didu
khidn
2
Chopper (80 biCn
ddi xung 6p)
3
BQ bidn ddi dien ap
xoay chi6u
BQ nghich luu
4
(inverter) (ngudn
dong ho{c ngu6n
Ao)
5
Cycloconverter
Chftc n5ng
Ung dung
Bidn ddi ngu6n xoay chidL
(AC) thAnh ngu6n mEt chi!u
(DC) thav ddi drJdc
Bidn ddi ngudn DC cci olnn
thAnh ngudn DC thay d6i
D0ng trong didu khidn dQng
cd DC, dQng cd kh6ng ddng
bO vii d6no co ddno bO
DDng trong didu khidn dQng
cd DC, dQng cd khOng ddng
dll.lc
h6
'Bidn ddi ngudn AC cd dinn
th?rnh ngudn AC thay ddi
dudc, qi0 nquv6n tdn sd
Bidn ddi ngudn DC thAnh
ngudn dp ho{c ngudn ddng
AC c6 diQn dp /tdn sd cd qnn
hoic thav ddi drJdc.
Bidn ddi ngudn AC cd dinh
thAnh ngu6n AC c6 diQn dp
1.1
D0ng trong didu khidn dQng
cd kh6ng ddng b0
Ding trong didu khidn dQng
cd kh6ng ddng bQ vir dQng co
d6ng b0
DUng trong didu khidn dQng
cd kh6ng ddng b0 vd dQng cd
NUAwg xuet NEU
2-
Dlnh
co aAu
mfl:c dQng co ad
,hay
BBD
h1;:Jfihji,-l*;:il,"Hl
chdp
mfc
1il"*i#.:?,,,1'""rtfir":J:;l;
grip dQng co d6p rlng nhanh vi d6 wgt qua
c6c n"u iai ng{n h?n.
BBD thudng srft dung linh kiQn bdn d6n c6ng
sudt. cdc linh kiQn
i dbng do kh6 ndng chiu nhiQt k6m
tlQ cao
TDD cdn sr? dung vdi dbng qud tAi
cdng sudt ldn hon so vdi dQng co.
Mit khdc, cdn lur ! rh, c6c BBD hi6n dai thudng c6 c6 tinh
n'ng
ua viQc gidi han dbng qud t6i cho
tnrdng hop qud t6i k6o dai. \n vdy, kl
dinh mric dbng cho hp thdng n6n gi
dQng co' Di6u ndv s6 gidm chi phi dau
tu cho hQ thdng vd BBD s6 b6o vQ
drroc dQng cd trong tnfdng hop qud tAi
ddi han.
Hinh 1'10 bidu di6n c6c gt6i h4n tr6n ddc tfnh co
cria mOt hQ thdng
llBD-DC didn hinh.
Tdc d0 crrc dai
C6ng sudt cgc dai
(qua
dQ)
M6men cgcdqi j
(qua dQ)
I
"
c,-, i
_
I
I
I
M6men c{c dei
(dii
_(0
hqn)
CHUdNG I
20
3. S6ng hdfi udt hQ etl eilng sudt
hdi
Tdt clc6c b0 bie'n ttdi dilng b6n ddn c6ng sudt ddu sinh ra s6ng
kh6ng sinh
tliQn dp vd dbng tliQn d ng6 ra' Cdc s6ng hdi niy thudng
tdn thdt (l6i' (
c6ng sudt hftr ich, mA ngrrgc lai, chrlng ldm gia ting
gi6 tri hieu
qudn) tr6n dQug co. NgoAi ra, s6ng hii ddng ldm tdng
co' Do d6' khi srl
cria dbng dQng'co vi lAm m6o d4ng til th6ng dQng
vdi cdc b0 bidn ttdi bdn d6n' tlQng cd thrrdng ph6i gi6m tlinh m
(d,erated.), c6 nghla lA t6i cria dQng co ph6i nh6 hon dinh mf'c'
g6v ra s6
Tdt cA cdc b0 bidn ddi ding b6n d6n cOng sudt c0ng ddu
ndv gdy
hhi dbrrg t4i ng6 vdo cria c6c b0 bidn ddi nDry. crlc s6ng hdi
bidndangho{csgtrdisutcriadiQnd'pludi,inhhudngl6ncdctaikl
bO bidn tldi cong
mdc tr6n cilng lrrdi diQn. Su chuydn m4ch trong cdc
ra nhi6u v6 tuydn tr€n lrrdi va
brl'c x4
ra kh6ng gian xung quanh'
Motsdcdcb0bidntldinhrrchlnhlrnrc6didukhidn,cycloconvr
biCt Ie khi
vd BBD diQn dp xoay chidu c6 hO sd cOng sudt thdp' d{c
viQc vdi diQn 6P ra thdP.
1.4 DtEu KHI€N
rdc s0
TRUYEN oOt'tc stEt.t
7- CAc thilng sd dAnh gi6 ehdt
'ts'tc
D0 crlng dic tinh co dugc tlinh nghia:
g=MI
'Ao
mdm'
vdi p l6n, ta c6 ddc tinh co critrg; F nh6, ta c6 dic tinh co
cho d0 chinh
DO dn ilinh tdc dO Gpeed' regulation); d{c'trung
duy tri tdc d0 d4t, x6c clinh bdi c6ng thr?c:
e-
0d -<o
ttJ6
;
e%o
=
to -'1oo
tD4
trong tl6: coa - tdc tlO il4t; co- t6-c d0 thrr.c'
D0 trcrr di6u chtnh tdc d0 ttugc tlinh nghia:
%,
u=
t(.I,i
trong d6: t4,
<,:r*,
- ldg ludt
la
ivdi+1'
cdc gs6tr! tdc d0 xdc l4p dn
dinh
6
NHANG
xun ufiu co
eAtt
27
TrI dAy, ta c6 thd phdn loai:
- Hc TDD ld v6 cdp n6u y +
d moi gi:i
giri
r, nghia ld h6 c6 thd rem vi6c dn rlinh
tri trong sudt d6i didu chlnh
t6.c dO.
- He rDD ld c6 cdp khi hc chi c6 thd ldm vi6c dn rlinh tai mQt sd
tri
cria t6'c d6 trong ddi didu chlnh tdc
116.
Drii diiu chinh tdc d0
Ddi didu chinh t6c dq (ho4c pham vi didu chinh tdc d0) ld ti sd gifia
t6c d0 ldn nhdt o,,^* vd giri tri t6'c dQ nh6 nhdt ahrn khi tli6u chinh:
D=%
0-l.t
Giri tri co-"* thudng bi han chd bdi dO b6n co khi vd cdu tao cria
ddng co. Gi6 tri axin bi han chd bdi y6u cau vd m6men khdi d6ng, kh6
nang qud tdi vd sai s6'tdc dQ cho ph6p. Nhrr vay, d6'i vd,i truy6n d6ng
diQn, dQ cd'ng ddc tinh co 6nh htrdng ldn ddn d6i gi6u chinh tdc d6. D6i
di6u chinh t6'c dQ cing cao ddi h6i d6 cri,ng rldc tinh co cfia he thdng
BBD-DC cdng ldn.
2- Chuydn trsng thdi td.m viQe hhi didu hhidn tdc d6
(M ultiquadrant op eration)
-t:r
@
b)
S., : Di6'm lam viCc ban ddu
S. : Didm lAm vi6c mdi
M
Hinh 1.11: Chuydn trqng thdi ld.m ui€c khi didu hhidn tdc d6
Mr",
CHUANG
phdn trr
Gia thidt hq thdng BBD-DC c6 thd ho+t dOng 6 cA bdn
th6i
mat ph&ng dic tinh co, hinh 1'11 bidu di6n srr chuydn trang
didm ldm viQc trong c6c trudng hdp sau:
1- GiAm tdc (cr)ng chidu quay) (H'1'11a)
2- DAo chiiu quaY (H'1'11b)
3- Tdng tdc (cirng chidu quay) (H'1'11c)'
phdn tu (sizl
Trong trrrdng hgp bq bidn ddi chi lhm viQc tren mQt
nh6 nhdt
quad,rant operation), mdmen dQng co chi c6 thd gidm xudng
khi gi6m tdc d
zero. Khi d6, sqr chuydn trang thrii cria didm ldm viQc
ra nhu hinh 1.12'
Sr - Didm lAm viQc ban ddu:
Sz - Didm lAm viQc mdi
------\s,
M
tu
Hinh 7.72: Gid.nt tdc hhi hC th6ng cht td.m viQc bAn Phd.n
I
sil r[P cHUdNG 1
hQ truydn dQng
1.1. Hinh 8T1.1 bidu di6n didm ldm viQc cfra mqt sd
cira clQng
khdc nhau, trong d6 M vd M" ldn lrrqt ld tl{c tinh co
viQc niry.
cfia tAi. Nhdn x6t vii tinh dn dinh cfia cric didm lAm
NHTJNG
KHA: NIEM
co
aAN
23
1.2. KhAo srit hG truydn dQng gdm mdt
d6ng co DC nam chdm vinh crfu
vdi ddc tinh co or = 1gg,4 - O,I.M
k6o mQt mrly ph:it DC cdp ngudn
cho t6i trd vdi ddc tuydn co crla
mdy ph6t ld. o= 2Mr. Tinh tdc clQ
vd mdmen d tlidm v4n hdnh xdc
lQp vd khAo sdt tfnh dn dinh c0a
didm vQn hinh ndy.
Hinh 8T7.2
M,[Nm]
r.3. Mot dQng co vdi b6 bidn ddi c6 ddc tinh co cho bdi hQ thrx,c:
M = eo)m + b. Tdi cria dQng co c6 dic tfnh co bidu di6n bdi h€ thfc:
M" = ca-2 . Cric h6 sd a, b, c ld cdc sd thrrc drrong.
a) Tim t6'c dQ ldm vi6c x:ic lap cria h6 thdng. x:ic dinh bidu thr?c li6n
quan gifra cric h6 sd dd c6 hai didm ldm vi6c c6't6c dQ drrong.
b) Xric dinh su dn tlinh cria cdc didm
lim
viQc ndy.
1.4. Hinh 8T1.3 bidu di6n didm ldm vigc ciia cric h6 truyOn clQng diQn
khzic nhau. NhQn x6t vd srr dn dinh cria c6c tlidm ldm vi6c nav.
Hinh 8T1.4
1.5.
Mgt dQng cd dudc cu+g cdp tu mQt b0 bidn ddi vd c6 ddc tinh co c6
dang: M - e(o^ + 6. DQng cd mang tai c6 ddc tinh co bidu di6n bdi hQ
thtc: M, = c(qn2 + d. Cdc hlng sd e, b, c, d,ld c6e sd thrr. c drrong.
a) Tim tdc d0ldm vi6c x6c l6p cria h€
CHUONG
1
chnns2
il\
^?
*r
rdC OO
D0NG cd Mor cHtEu
DIEU KHIEN
2.1 TONG
OUAN
DQng co mQt chi6u (cdn goi ld dQng co DC) thrldng drtoc sir dung
r6ng r6i trong c6c hQ truydn dQng cAn thay ddi tdc dO you cdu ddi didu
chinh ldn, dQ dn clinh tdc do cao v2r cric hQ thrldng xuy6n hoat clQng d chd
d6 khdi dQng, hdm vd dAo chidu. Mot sd rlng dung quan trong cria dQng
co mQt chi6u nhrr truydn dQng cho xe diQn, m:iy cdng cg, mdy ndng v{n
chuydn, m6y c6n, mriy nghidn (trong cdng nghiQp gidy).'
chuong nay s6 gidi thiQu dic tinh unh cria clQng co DC, cdc phtrong
phrip hnm vd khdi d6ng, gidi thiQu so b6 cric phuong phrip ili6u khidn tdc
d0 dQng cd DC.
D{c tinh cd tinh cfra dQng co mQt chiiu
Hinh 2.1 gidi thiQu c6c loai dQng co DC th6ng dung, bao gilm ddng
cd DC kich tir dQc l4p, kich tr] song song, kich tii ndi ticp vd kich til h6n
2.1.1
hgp.
Vdi dong cd DC kich tr] clQc l4p, ddng phdn rl'ng vd dbng kich tr} c6
thd di6u khidn dOc l4p vdi nhau. Vdi rlQng co kich tt song song, phdn
r1'ng vd cu6n kich til drroc ddu vdi ngudn cung cdp. Vi vay, vdi loai dQng
cd ndy, dbng phdn rlng ho{c dbng kich tit chi c6 thd dudc d,idu khidn aloc
lap bxng crich thay ddi dien trd phu trong mach phdn fng ho{c mach
kich tt. Tuy nhi6n, cldy ld crich didu khidn c6 hiQu sudt thdp. Vdi d0ng
co kich tir ndi tidp, dbng phAn rlng cflng ld ddng kich til, vd do dd, tr]
th6ng dQng co ld mQt hdm cria ddng phdn rl'ng. Vdi clQng co kich tir h6n
26
CHUANG 2
+
)
b)
V*,
A2
a)
It
_.1 S,
c)
la,
s2
d)
A2
Hlnh 2,1: Cdc loai dQng co m6t chi6u th|ng dung
a) Kich td d|c lfup; b) Kfch til song song
c)
Kich ttt ndi
tidp;
d) Kich
tt
h6n hop
Mach tudng duong d ch6'd0 tinh cria dqng co m6t chidu drroc
bdy d hinh 2.2. DiQn trd ^R,, bidu thi tliQn trd phdn rlng. Ddi vdi dQng
m6t chiiiu kich tr] dQc lap hodc kich tt song song, diQn trd ndy ld ili
trd mach phdn rirrg, Ddi vdi dQng co kich tU nO'i tidp ho4c dQng co kich
h6n hop, R,ld tdng diQn tr8 cfia cuQn phdn rrng vA. cuQn kich tir ndi tidp.
ItJ
Ru
Lu-
E=
Koro
(l
Hinh 2.2: Mach tuong duong chd d6 tinh crta d6ng co DC
Phuong trinh co bdn cfia dQng co mQt chidu lA:
E=KQo
V=E+RnIu
M = KQII
trong d6: O - til th6ng tr0n m6i cqrc (Wb);
.I, - dbng phdn rturg (A); V - tliQn dp phdn fng ff);
R, - diQn trd phdn rlng (A); or - tdc d0 g6c truc dQng co
(
otEu xutEu r6c oQ oQxo co Mer cnEu
Til cdng thrl'c (2.1) - (2.3), ta
hodc:
27
c6:
'=ft -fuu
'=# -#,M
(2.4)
(2.5)
Ltru f ld cric c6ng thrlc tir (2.1) ddn (2.5) c6 thd rip dung cho tdt c6
loai d6ng co mQt chidu da kd d tr6n.
Vdi ddng co mQt chiiu kich tt dgc ldp, ndu diQn rip kich tir duoc duy
tri kh6ng ddi, c6 thd giA thidt rlng til th6ng d6ng co clng kh6ng ddi khi
mdmen ddng co thay ddi. Khi d6, ta c6:
cdc
K.@
=
(2.6)
const
Nhu v{y, theo (2.5), d6c tinh co cia d6ng co mQt chi6u kich tir d6c
lap ln mQt drrdng thEng, nhu v6 tr€n hinh 2.3. Tdc dd kh6ng tdi cfia
dQng co xr{c dinh bdi di€n dp cung cAp V vA til th6ng kich tr} K.O. Tdc
d0 dQng cd suy gi6m khi m6men tAi tdng vd dQ dn dfnh tdc d0 phu thuQc
vio diQn tr6 phdn tng Ru. Trong thtr. c td, do phin rl'ng phdn frng, tir
th6ng dQng co gidm khi m6men ttrng, d6n ddn tdc d0 dQng cd suy gi6m it
hon li tinh to6n theo c6ng thrlc (2.5). Vdi m6men ldn, tr} th6ng c6 thd
suy gi6m tl6h mrlc dq ddc dic tinh cd trd n6n dtrong d6n tldn hoat dQng
kh6ng dn tlinh. \A v{y, cuQn bi thudng hay duoc sfr dung tld ldm girim
hiQu rlng khfi tir cria ph6n rlng phdn dng. Vdi dQng co c6ng sudt trung
binh, dQ sut tdc khi tai dinh mrl'c so vdi khi kh6ng tiliktroilng 1Vo.
Vdi d6ng co mQt chi6u kich tr] ndi tidp, trl th6ng <D ld mQt hdm cia
ddng phdn fng. Ndu gid thidt dQng co hoat dQng trong ving tuydn tinh
cria ddc tinh til h6a, c6 thd xem ld til th6ng ti 16 bdc nhdt vd'i ddng phdn
fng, nghia ld:
e
= Knt.In
(2.7)
Thay (2.7) vdo (2.1), (2.4) vd (2.5), ta duoc:
M = K.Kn,.Int
v
K .Kht.Iu
Ru
K'Kp,
(2.8)
(2.9)
(2.10)
28
CHUONG
to(o/o<rldm)
(a) DQng cd DC kich trl dQc lflp
(b) DQng cd DC kich tJ nditidp
(c) DQng cd DC kich t0 h6n hQp
(a)
(c)
(b)
'
M(o/.Mdm)
Hlnh 2.3: Dec tinh co ctic loai d6ng co DC
Ddc tinh co cfia dQng co m0t chidu kich trlr ndi tidp duoc v6
hinh 2.3. C6 thd thdy rlng tdc dQ ddng co suy giAm nhi6u theo
tdi. Tuy nhi6n, trong thrJc td, cric dQng cd ti6u chudn thrrdng duoc th
kd lAm viQc tai didm cdnh ch6 (knee-point) cta ddc tinh tr] h6a khi
t6i dinh mrlc. Vdi tdi tr6n dinh md'c, mach trf dQng co b6o hda, khi d6
bh6ng O kh6ng thay ddi nhidu theo ddng tei Iu, d6n ddr dIc tinh co ti
cQn vdi dudng thlng.
DQng co mQt chidu kich tr] ndi tidp thich hop cho cdc rlng dung
h6i m6men khdi dQng cao vi c6 thd quri tAi n4ng. Vdi m6men t6i
trl th6ng clQng co cfrng tdng theo. Nhu vfy, vdi cDng m6t luong gia
cria mdmen nhr.f nhau, ddng phdn tng Iu cria dQng co mQt chidu kich
ndi tidp s6 tdng it hon so vdi dQng co kich trl dQc l{p. Do d6, trong
kiQn qu6 tdi ndng, srt qu6 tdi cria ngudn cung cdp vd su qu:i nhiQt
dQng co cting.ft hon so vdi khi dirng tlQng co kich tt dQc IQp.
Theo c6ng thfc (2.10), t6'c dQ dQng co kich tr] ndi tidp ti lQ
vdi cdn b{c hai cfia m6men. Vi v4y, t6'c d0 tlQng co khi kh6ng t6i c6
tdng l6n rdt cao, cht bf han chd bdi tU du cria dQng co vA c6 thd gdp
chuc ldn t6'c dO dinh mrlc. Didu ndy li kh6ng cho ph6p vdi mdy di
thudng chi cho ph6p hoat dQng gdp hai ldn tdc dO dinh mr1c. Do d6,
co kich tU ndi tidp khdng duoc dlng vdi c6c rlng dung trong d6
tili c6 thd nh6 ddn mrlc lim tdc d0 dQng cd vrrgt qud mri'c gidi han
ph6p.
2
otEu xutEn r6c oQ oQNa ca M)r cutEu
Dac tinh cfia dQng co mOt chidu kich tt h6n hgp c6 dang nhu bidu
di6n tr6n hinh 2.3. Tdc tlO kh6ng t6i cta dQng co phu thuQc vdo dbng
kich ttr qua cuQn song song, trong khi dO ddc d4c tinh co phu thuQc vdo
tit h6n
srr phdi hgp gifra cuQn song song vA cuQn ndi tidp' DQng co kich
hop ttugc sir dung trong nhfrng rlng dr;ng cdn c6 ddc tinh cd tudng td
d mot
dQng co kich tu ndi tidp il6ng thdi cdn h4n chd tdc ilo kh6ng tai
giri
tri gidi h4n thich hoP.
Cffng cdn luu y Ia c6c d{c tinh co d6 cQp tr6n hinh 2.3 la dic tinh
flong
cd tr/ nhi6n cfia dQng cd, nghia ld cdc ddc tinh ndy nh{n d'.rgc khi
c6
co hoat tlQng vdi dien dp cung cdp vi til th6ng dinh mrlc, vd kh6ng
rliQn trd phu ndo trong mach phAn rlng ho{c kich tt'
2.1.2 Sd lrtgc c6c phr/dng ph6p diiu khiin tdc d0 dQng cd DC
TrI c6ng thrlc (2.5) bidu di6n quan hQ gifa tdc tlQ - rn6men dQng co'
phrrong
c6 thd thdy rlng tdc ctQ dQng co c6 thd duoc tlidu khidn blng ba
phzip sau:
1- Didu khidn cliQn :iP Phdn ri'ng
2- Didu khidn
tt
th6ng
trd Phdn tlng
1- Didu khidn d.iQn d.P Phdn fing
D6c tinh cd tinh cria dQng co kich tir aloc lfp vd kich tir ndi tidp khi
tlidu chinh tliQn 6p cung cdp cho phdn rl'ng clQng cd dudc v6 tr6n hinh
Bhng
2.4a,b. cric tt6c tinh ndy suy ra tt (2.5) vdi cliQn rip V thay ttdi.
ki tdc
c6ch thay ddi tlien dp phan r1ng, dQng co c6 thd ldm viQc tai bdt
vd trgc m6men' Vi
dQ - momen ndo nxm gifra tlrrdng tldc tinh co trr nhi6n
phrip niy
rliQn 6p phdn fng chi c6 thd tlidu chinh drrdi dinh mfc, phuong
dnc
chl ding tld rlidu khidn tlQng co ho4t dQng vdi cdc d6c tinh thdp hcrn
tinh co trqt nhi6n.
Tinh chdt quan trqng cfia phuong phdp ndy ln d0 crrng ddc tinh co
he c6
khong thay cldi khi tdc dO .loug co dugc tti6u chlnh. Didu ndy khidn
cuc dai
khA n6ng cl6p rlng vdi tii c6 rnomen hXng sd vi dbng ptrAn rlng
- cia
chqph6p Iu* - tudng ring vdi nd ld m0men tAi crtc dai cho ph6p
3- Didu khidn tliQn
dQng co gitr kh6ng ddi vOi moi tdc tlQ.
D!
30
CHUONG 2
't0
0v
I'h
I'0,
ph
rlI
llll
lul
Htnh 2.4: cdc'dQc ttnh co khi didu khidn diQn tip phdn
tng crta d,Qng co
a) DQng co ktch ttX dQc IQp; b) DQng co kich ttX
ndi tidp DC
DiQn dp phcn ring dQng co c6 thd duoc didu khidn
blng
c6ch sfi dung:
- Mdy phdt DC (HQ Mdy phdt _ DQng co)
- B0 chtnh hnr c6 didu khidn (AC + DC)
- BQ Chopper (BQ bidn ddi xung dp) (DC + DC)
cdc phuong phdp di6u khidn ndy s6 drroc khao srit chi
chuong 3.
htl
hnt
Yrt
Ir,
tidt trong
Didu hhidn til th6ng
Didu khidn tr' th6ng dtroc sfi dung khi cdn tdng
tdc do ldm viQc cria
dOng co cao hdn tdc d0 dinh mri'c. c6 thd thdy
didu d6 qua c6ng thrl,c (2.5).
Drc tfnh tinh cfia dQng co kich td dQc ldp vd kfch tr] n6'i
tidp khi
di6u khidn tu th6ng duoc bidu di6n ldn lrrot tr6n hinh
2.4a, b blng cdc
dudng n6t dft. L,Jrr y ld dQ crlng d4c tinh co giam
nhanh khi gidm tu
2-
th6ng.
Tdc dQ cao nhdt cria dQng co dat drrgc
khi eiem tir th0ng bi hAn ch6 bdi:
- srr kh6ng dn rrinh cria dQng co gdy ra bdi dnh
hudng cfia phrin r?ng
phAn rlng,
- Gidi han v6 mit co khf cria'dQng co: cdc dQng co
th6ng thrrdng cho
ph6p tdc t10 tlat ddn 1,b - 2 tdn tdc d0 dlnh mf,c.
M6t sd dQng co ch6- tao
dec biQt cho ph6p tdc d9 cao nhdt dat td'i 6 rdn dinh
mrtc.
Ddi vdi dQng co DC kich trl dOc l{p vd song song, c.ng suft
crr. c dai
cho ph6p cria dOng co gan nhrr kh6ng ddi vdi moi tdc
do khi tlidu khidn
til th6ng (xem hinh 2.il. CA thd tha'y didu n.y ndu gi6 thidt le ddng
crr. c
dai cho ph6p.
If
h
Ir
otEu xurEru
rdc oO oONa ca Mor cutEu
31
ddng cria dQng co, E = V - R,Iu - ld hlng s6'. \A vAy, c6'g sudt di6n tU
crrc dai cho ph6p cfia dQng co ld. 81,,,,,,,,, s6 ld hhng sd, vd m6men cuc dai
cho ph6p cria d6ng co s6 bidn thi6n ti 16 nghich vdi tdc d6.
Luu y ld trong thrrc td, gie thidt db'g phan fng cuc dai cho ph6p
Iu-.* kh6ng thay ddi khi giem tir th6ng chi li gdn dring. Tric d6ng cria
phdn rlng phdn rl'ng cdng ldn khi tt th6ng cd'g gidm, do do, ddng phdn
ri'ng cuc dai cho ph6p can gi:im xuong d0 kh6ug sinh ra tia ltla di6n quri
rnri'c tr6n c6 g5p. Didu ndy da' ddn vi6c giri tri thuc te ctia l,,,no., sE giam
xu6'ng khi tdc d6 tdng cao.
vdi cl6ng co DC kich tr] d6c lap, vi6c diou khien kich tir dtroc thtrc
hi6n bdng crich thay ttdi di6n dp kich tu vdi b0 chinh luu c6 didu khidn
hoac b6 chopper, tiy theo ngu6' cu'g cdp duo-c str du'g ld AC hodc DC.
Vdi d6ng co c6ng sudt nh6, cr)ng c6 the m6c ndi tiep bidn trd vdo mach
kich trl dd aidu khidn tr} th6ng.
vdi ddng co DC kich tt no'i tic'p, vi6c di6u khien tir th6ng drroc thuc
hiQn bing crlch mdc di6n trd song song vdi cu6n kich tu. MQt s6'dQng co
kich til noi tidp c6 cu6n kich ttr nhi6u ddu ra, vd do d6 c6 thd thav ddi
tit th6ng bing crich thay ddi sd vdng dAy cu6u kich trr.
Didu hhidn hdn hqp d.iQry Ap phd.n tng vd. til th6ng hich til
Phuong phrip ndy duoc st? dung khi can di6u chi'h t6'c atO d6ng co
lrong mQt drii rQng tron vd drrdi tdc dQ dinh rnf'c. Toc d6 drJdi tdc d0
rlinh mr1'c drroc di6u khidn bing cdch thay d6i di6n zip phdn f'ng trong
khi gifr kfch tt 6 gi6.. tri dinh md'c. Tdc d6 tr6n dinh mr1'c duoc di6u
khidn bing crich thay ddi di6n rip kich trl.
Gidi han ctia m6men vd c6ng sua't ra khi alieu khie' h6u hop di6n
phdn
dp
rlng vi tr} th6ng kich tt duoc v6 tr6n hinh 2.5.
3-
M' P' Iu
J
oie, rnidn dien dp phdn
r.rng
Di6u khidn tu th6ng
CHUONG 2
4- Didu hhidn diQn trt Phdn ilmg
Hinh 2.6 bidu di6n d{c tinh co cfia dQng co DC kich tr} dQc lQp vd
ndi tidp khi didu khidn t6'c dQ bhng c:ich them diQn trd phu vdo phdn
fng.
Khuydt rlidm chinh cria phrrong phaip ndy ld hieu sudt cria h€ thdng
rdt k6m vd do cfng d{c tinh co thdp, nhdt le, khi hoat clQng & tdc d0
thdp. Do d6, phrrong phdp ndy hi6n nay it khi drroc sir dung tld tli
khidn tdc d0 dQng co, trit cric tnrdng hop:
- Khdi tlQng dQng co,
- Thay ddi tdc d0 dOng cd trong mQt thdi gian ngdn trong
ng{n han hoic ng{n han l{P lai.
ol
(D
Tdng R phq
Tdng R phq
M
Hinh 2.6: DQc tinh d6ng co DC khi thOm diQn tr& phu ud'o phiin tng
a) DQng co kich td dQc lQp; b) DQng co hi.clt td ndi tidp
2.1.3
Khdi d0ng
Ddng phdn rlng cria dQng co DC trong quri trinh quri dQ, nhd chd
khdi tl6ng, cdn drroc gidi han tld tranh ph:it sinh tia Ifia diQn qud m
tr6n cd g6p ctQng cd. Th6ng thudng, vdi tlQng co kh6ng c6 cuQn bi,
ndy gid'i han d mfc hai ldn dbng tlinh mrlc. Vdi dQng co c6 cuQn bi h
thidt kd clqc biQt, dbng cliQn ndy cho ph6p l6n ddn 3,5 ldn ddng
mrlc.
Khi cdp tliQn rip dinh mrlc trrrc ti6p trong chd d0 khdi dQng,
phdn rltrg dQng co DC c6 thd lcn ddn cd 20 ldn dbng dinh mrlc'
khdi dOng ndy gAy ra phrit sinh tia lfia diQn qu:i mrlc trdn cd g6p vd
nhiQt trong cuQn ddy phAn rlng. Ddng khdi dQng clgng cd, do d6, cAn
han chd bhng crich gi6m tliQn 6p dat l6n phdn rfng.
Trong thrrc td, cdc b0 bidn tldi dnng dd tlidu khidn tdc c10 'ilQn
cflng duoc sir dung dd han chd ddng tlQng co khi khdi d6ng. Cric bQ
ddi nay thrrdng c6 chrlc ndng han chd dbng diQn trong quri trinh
oilu rruE* rdc oQ oQNo co MOr curEu
33
bidn ddi, mot bo diQn trd kh6i dQng drroc thcm vdo mach phdn rlng d6ng
co khi khdi dQng tld han ch6'ddng. cdc diQn tr6 trong b0 di€n trd
khdi
dQng ldn lrrot drroc cfit ra (ho{c n6i tdt) trong qud trinh khdi d6ng,
vd
duoc tinh chgn sao cho ddng qua dQng co drJoc han chd d. mri'c cho ph6p,
trong khi van cldm brio m6men crQng co sinh ra dfi dd gia tdc dQng co.
2.1.4 CAc tr4ng th6i h6m
Trong chd dQ him, d6ng co hoat dQng d chd dO mdy phrit: nhQn
ndng luong tu tei vd bidn thinh diQn ndng. Tty theo cdch ti6u t:in ndng
lrrgng nd.y, ta c6 cfo phrrong ph:ip hdm khric nhau:
1- Hdm trii sinh
2- Hdm tlQng ning
3- Hdm ngugc
Hdm tdi sinh (Regeneratiue braking)
Trong chd d0 h6m trii sinh, dQng,co nh{n ndng luong tr} t6i, bidn
thdnh di6n ndng va tr6 vd ludi. Dray ld phuong phrip ham c6 hi€u sudt
cao nhdt.
7-
EQng co DC kich
til
d6c ldp
Mach tudng duong vd ddc tinh co cria clQng co DC kich
t,rong chd dQ hdm tdi sinh drroc bidu di6n tr6n hinh 2.7.
R./
L,r
dQc lap
Iu
lEt >
lvl
+
+r
+ cKTl
n)
tJ
'l
Hinh
"?'113,f
"
n'a," uf
b)
tdi sinh d6ng co kich ttl d6c ldp
duong; b) Dd.c tinh co.
Trong chc'do h6m tdi sinh, sdd E cdn ph6i ldn hon ngu6n 6p cung
cdp v vd ddng qua dQng co chay theo hrrd'ng ngudc lai so vdi chd d0 dOng
t!u, Khi sri'dung bQ bidn aldi brin d6n, cdn lft
Jr la d chd dO hdm trti sinh,
lr0 thong BBD - DC phai c6 khd ndng tdi ddng theo cd hai chi6u, hodc
plrrii dao chidu drroc diQn 6p ra. Dd thuc hiQn,tlrrgc didu nay, BBD phai
c6
2.7: Hdm
a) Mc.tch tuong
.
otlu xnEr,t rdc oQ oeNa co MOr curEu
33
bidn ddi, mot b0 diQn trd kh6i dQng duoc th€m vdo m4ch phdn d'ng
d6ng
co khi khdi dQng tld han chd dbng. cdc diQn trd trong b0 di€n
tr6 khdi
dQng ldn lrrot duoc c6t ra (ho{c ndi tdt) trong qud trinh khdi
dQng, vd
drroc tinh chon sao cho ddng qua dQng co drJoc han chd d. mf'c
cho ph6p,
trong khi v6n dim brio m6men dQng co sinh ra dn dd gia tdc dQng
co.
2.1.4 CAc trgng th6i hdm
Trong chd d0 hdm, d6ng co hoat cl0ne 6 chd d0 mdy phdt: nhAn
nlng luong til tai vd bidn thdnh di6n ndng. Tiy theo cdch ti6u trin ning
lugng nd.y, ta c6 cfo phuong phrip hdm khric nhau:
1- Hdm
t6i sinh
2- Hdm clQng ntrng
3- Him ngugc
7- Hd.rn
tdi sinh
(Regeneratiue braking)
Trong ch6'd0 h6m t:ii sinh, d6ng co nhan ndng luong tr] tdi, bidn
thdnh di6n ndng va trd v6 lrrdi. Day ld phrrong phrip ham c6 hi6u
sudt
cao nhdt.
kich til d6c tdp
Mach tudng duong vd ddc tinh co cria d6ng co DC kich tir d6c lap
trong chd dQ hdm tdi sinh duoc bidu di6n tr6n hinh 2.7.
DQng co DC
RUr,,
Iu
tEt >
+
+
tvl
"?'il3,f "
n'a' uf
@r
+ cKTl
r)
-l
b)
Hinh 2.2: Hd.rn tdi sinh d6ng co kich ti d6c tdp
a) Mc.rclt tuong duong; b) Edc tinh co.
Trong chc'd0 hdm tdi sinh, sdd E cdn phai ldn hon ngu6n dp cung
cdp v vi ddng qua dQng co ch6y theo hudng ngugc lai so vdi chd d0
d0ng
cd, Khi sfi'dung bQ bidn adi ban d6n, cdn lru f ld d chddQ ham tdi sinh,
lrQ tho'ng BBD - DC phdi cd kh6 ndng t6i dbng theo cd hai chidu,
hoic
phrii dao chidu drroc diQn 6p ra. Dd th{c hiQn
didu
niy,
BBD
ph6i
c6
$rrgc
,
CHUONG
phdn rlng vd tt
Blng cdch ilidu khidn tliQn dp phdn rrng' ddng
theo y6u cau truydn dQng'
rlng ld momen h6m c6 thd tlugc didu khidn
DOng cd DC hich tit ndi tidP
d chd d0 h6m tdi sin
DQng co kich tir ndi tidp kh6ng thd dnng
co DC kich til ilQc l4p'
bhng cdch ndi mach don giAn nhu dQng
cd kfch tr} ndi tidp trong
Phrrong phrip thrrdng sfi dung cho dQng
co nhu mQt dQng co kich til song song'
dQ ham t6i sinh li ndi tlQng
trd phu tld han chd dbng
kich tt lfc ndy drroc ndi tidp vdi mQt diQn
phdp khric' nhrt s6 ttd c{p
til trong mQt pham vi an todn' MQt phrrong
hinh thich hop
I chrrong niry, IA sfi dung bO bidn tldi chopper vdi cdu mQt dOng co ki
dOng tudng t{
tldu ndi lai cugn kich tU tld tlEng cd ho?t
tir doc lap.
2- Hom dQng nd.ng (Dynamic braking)
tlttgc thr'rc hiQn bXng "U:1
ViQc ham dQng ndng vdi cl6ng cd DC
i
dQng cd qua mQt q
fng
phdn
ndi
ve
cd
dOng
nai
t
,u
.dp
,rEudr, .urrg
mQt mdy phrit' t4o
trd thich hgp' DQng co hic ndy hoat tlQng nhrr
I
m6men h6m.
Sotld{lAudAyciradQngcoDCkhih6mdQngn6ngtrinhbDry6
2'9 cho tlQng co kich tr] ndi
2.8 cho tlQng co kich tr] tlOc l4p vd hinh
Ru
Lu
R,: L,r
I,-t
a)
c) Hd.m d6ng nd'ng
6nh hrrdng ddn ddc tinh co khi h6m'
.
ttt kich til
otEu xutEN rdc oQ oQua co MOr curEu
35
Iu
sl
s2
l
a)
b)
Hinh 2.9: so d6 ddu ddy khi hdrn d6ng niing dQng co kich
tt
nrii tidp
co;
b) Chd dQ hd,m dQng nd.ng tu klch tt
Hinh 2.10a bidu di6n d4c tinh co cfia rlQng co kich trr cl6c l{p khi
hdm cl6ng ning vdi c6.c gi6 tri diQn trd h6m kh6c nhau. Lft y ld trong
trudng hop hdm dQng ndng trJ kich tt, rlng vdi m6t gi:i tri ctia diQn trd
hdm sE c6 mQt gir{ tri tdi han (critical) cria t6'c d0 <o,r,, vd,i t6'c tlQ thdp
hon girl tri tdi han ndy chd tlO mdy phdt cria dQng cd s6 kh6ng x6y ra vi
didu kiQn tu kich kh6ng th6a (a\r,r, rr152 tr6n hinh 2.10). Do d6, vdi tdc dQ
nh6 hon t6'c d0 tdi han di n6i, m.Omen hdm blng zero vd. ndng luong chl
drroc ti6u hao blng ma sdt trong hO truydn clQng.
Vdi tl6ng cc kich tU ndi tidp, khi hdm dQng ntrng cdn d6o chidu cuQn
kich tu hoic phdn ring dd tr6nh vi6c ddng qua d6ng co dao chidu gdy khrt
til dQng co. So tl6 ddu ddy nhu hinh 2.9. Ddc tinh d6ng co khi h6m clQng
ning bidu di6n tr6n hinh 2.10b. Ddc tfnh ndy c6 thd tinh todn tir c6ng
th(tc (2.4) vd (2.5) bhng cdch thay gi6 tri V = 0 vd .8, ld tdng cria di6n
trd phdn rlng vd cliQn trd hdm, ddng thdi c6 tinh ddn ddc tinh trr h6a cria
a) Chil d6 d6ng
dQng co.
----
Kich trl dQc lqp
TrJ
kich
ttJ
Rht
t
b)
Hinh
2.7O: DQc
tinh
tt
co
cia d6ng
ldp;
co
DC khi hdm d6ng nd.ng
tt ndi tidp
(2.L0),
Theo c0ng thrlc
trong vr)ng tuydn tinh cria ddc tfnh tir h6a,
t,()'c d0 trd n6n tlOc l4p vdi m6men ddng co vd cho bdi c6ng thrfc:
a) DQng co ktch
d6c
(\h = R'
ffi
b) DQns co kich
(2'r7)
DAy cflng ld tdc d0 tdi han tr6n ddc tfnh hdm cria dQng co; dtrd,i tdc
CHUANG 2
3- Hd.m ngdqc
sone sone)' chd dQ
dOc lap (hoac kich til
tu
kich
.,.:"
dsns
vor
D6i
;;:Tr";:;"""Dc
nhidu
d6o chidu
co nin
:':.::::u;;
ngu6n hoac phdn tlng tlQng I
tinh
crrc
rakhi
xhy
hdm ngrrgc
, ^a ^x -x .hiArr nsdOc vdi
i'oat aong Dong qua. dQng :" ::
h6m. so d6 ddu
.nu uu dQng co vir sinh ra m6rne'
ndi vdi (
d chd tro ham ":"1:
cuc ti
nu- nsusc thtrc hiQn bxng crich dzio
ffil;iltf il;
::in:"J#:[;:
:1T::"'"'* il::1:1:
:il:TJJ".,:ff
il;;;'
:iff","H
::"fltr ff ;i;:""""
hinh 2'1lb'
phdn fng ho4c cuQn kich tU nhu
lu
CKT
sr
'--
A1
s2
T
+\
I-
b)
a)
co DC
Hinh 2'11: Hd'nt' nguoc d6ng
trl ndi tidp
td'p; b) DOng co DC lzich
d6c
tt
hich
DC
co
DQng
a)
fng dd han
diQn tro vb'o mach phAn
Th6ng thrrdng, cdn thOm
dbng h6m d ei6 tri cho Ph6P'
Dic tinh cd ciia clQng co kich
;
"#T#H; ;
:ff'J#";;r'o
nt""n
tir dOc lap,v1
t u:,u.i',
i'ii::':";:U:,::t
::1 i:"
(2'10)' Momerr
honc:?;,:i'i^:f'.:
"''cong thfc (2'5)
cdc
r--.--- Ja'h;'n
difns
dttug
dnug de'Jrarn
"o"*Khi hrm
zero'
ffId
"gda".du.el
:^;:':TitH
+ zeto llru
o
"v ^- ----'
,2._ clQ
)A gdn bXng zero' nOt'u' kh6rrg'
-. , t . tdc
uuu
cdp khi
cd, cdn ngdt ngudu cung
ngrroc lai'
cd se gia tdc theo chi6u
L-Lr Arr
C)
Kich ttr doc laP
Kich tJ ndi ti6p
6 clt'd d6 lt'd,nt. nguqc
Dd'c tirl|t. co d6ng co DC
oEu rcnEN rdc o0 o1xe co MOr cutEu
37
H6m
ld phuo'g phdp hdm cho hi6u suat thdp, vi n6ng ruong ciia
'gudc
tai vd ngudn ddu ti6u hao hdt tr6n di6n tro phdn rlng vd diQn trd hlm.
2.f.5 HC truy6'n dQng dQng cd DC kich trl dQc ldp c6 h6m
PhrAn l6n c6c h6 truy6n dQng cd hdm (multiquadrant drive) vdi cdc
bQ bidn ddi ban d6n thudng srr dung chd dO hdm tdi sinh.
Hinh 2.13 cho thdy cuc tjnh cria ngu6n V, sd'c di6n d6ng d6ug co E
vd chieu dbng phdn tng 1,, trong cric phdn tu lem vi6c kh:ic nhau. Cdc
dai lrrong V, E vd 1,, dudc xem lA drrong khi d6ng co hoat d6ng trong
phdn tu I (ctrd d6 d6ng co).
'
Khdo seit tr6n cho thdy rXng dd hC th6'ng hoat d6ng duoc <j. chd d6
d6ng co vd hdm tdi sinh theo chidu thudn (phdn td I ve II). b6 bidu doi
cdu cung cdp di6n rip drrong va c6 khd ndng dAn dbng theo cd hai chidu.
Dd h9 th6'ng hoat d6ng drro-c ci chd d6 d6ng co theo chi6u thuan vd hdrn
tdi sinh theo chi6u ngudc (phtin tu I va III). bo bidn cloi cdn c6 khd
rudng cung cdp di€n rip theo cr,i hai chiou nri khorig cdn kha ndng ddo
chidu dbng. D6' h9 thdug hoat ddug duoc d' cd l.rdr, phlin tu, b6 bi€n dOi
cdn c6 khri ndng tlzio chidu dbng vA dp.
L6
f
V<E
+
\-
Hdm theo chidu thuAn
V>E
\-
Dong co theo chi6u thudn
M
tvt>
tEt
G
+
_)
tvt<tEt
\_
3E
d6 didu khidn
Phdn tidp theo chuon g 2 sE t{p trung khrio srit vdn
diQn zip phAn
tdc d0 dQng co mQt chi6u bXng phrrong ph6p tlidu khidn
gdm:
rlng. Cdc hQ thdng BBD-DC tluoc khio sdt sE bao
- HQ mdY Phdt - dQug co
- H€ chinh lrru - dQng co
- HC BBD xung dp (Clt'opper) - dQng co
2.2 HE rvrAv pHAr - O0r,rc ca
ftF
THdNG WARD-LE1NARD)
.1"
DCSC
F - mAy ph6t DC
D - dQng cd
OCSC - dQng cd sd cdP d0ng
truydn dQng cho m6Y Ph6t F'
thudng la dQng cd kh6ng ddng bQ
CKTF, CKTD - cuQn kbh ti/ m6Y
phat F, cuon kich tiJ dong cd D
Hinh 2.14: So d6 nguYAn
Ii
he F-D
la hQ F-D' drroc
So d6 cdu tnic mriy ph:it-ilQug co, ho[c goi tdt
bny d hinh 2.14.
rip ra ctia
DiQn rip cung cap cho phdu ri'ng dQng cd D la diQn
phdt F. DiQn dp ndy duoc di6u :hinh bhng c:lch thay doi kich
CKTF'
mdy phrit F qua vi€c didu chinh cliQn :ip cung cdp cho
tt
:
otEu xutflN r6c oQ oQr'to co M)T cutEu
Phrrong
trinh
ddc
tinh
39
co cria hQ F-D:
EF & +R,
*=6--ffi*
(2.r2)
trong d6: Ep - stc diQn rlQng mdy phdt F, (V);
.Rp
- tliQn trd phdn ring mdy phrit, (Ohm).
KA - tn th6ng d6ng
co.
/
V = const. GiAm O
_----I
-
Dic tinh tq
nhiCn
Thay ddi V.
O = const
M
Hinh 2.75: Dac tinh co hA F-D
Hinh 3.2 bidu di6n dqc tinh co cria h9 F-D. HO thdng c6 thd hoat
rlQng linh hoat o cd bdh g6c phAn tu. Tuy nhi6n, dQ crllg d4c tinh co hQ
lrd bi suy gi6m so vdi d0 crl'ng ddc tinh co cia d6ng co do phdi kd th6m
tllQn trd phdn f'ng mriy ph:it trong m4ch phdn rlng.
Ddi di6u chinh tdc d0 cfia hQ hd khoring 6:1 tldn 8:1 (vdi hG c6 c6ng
rudt trung binh). Vdi he thdng didu khidn vdng kin, d6i di6u chinh tdc
dQ
D c6 thd l6n tdi 200:1 ho{c cao hon.
Nhrroc tlidm cria h6 ld c6ng sudt ldp ddt ldn:
luJt
ph.t.
dQng co chdp hdnh,
it nhdt gdp ba Idn c6ng
kh6 didu chinh sAu tdc tlQ do
tt
drr cfia m6y
I
CHUONG 2
40
2.s rdNG ouAN vE ne rHdruo s0 cHinH Lttu - o0ruc cd Dc
2.3.1 Cdc dang mach th6ng dung
Deng mech
Loel
chlnh
ltJrr
D6l cOng
sudt, kW
Tiln sd 6p
chlnh lft
< 0,5
(f: tdn s6'
G6c phlln trl
hoet dOng
f
Tia mQt pha
Iu
l'/di)
<15
Cdu mQt pha
didu khidn
bdn phdn
Cdu mQt pha
di6u khidn
toAn phdn
(<75 trong
cdc ddu
2t
Iu
mAy xe
diQn)
E
<15
(<75 trong
cdc ddu
m6y xe
2t
diQn)
Chinh lrru k6p
mQt pha
<15
2l
ba pha tia
<50
3l
ba pha cdu
didu khi6n
bdn phdn
< 100
3f
ba pha cdu
didu khidn
toAn phdn
< '150
6f
B
N
Chlnh luu k6p
otEu xutEt't r6c o0 oQxa co MOr cutEu
4'J.
2.3.2 Cdc th6ng sd d6nh gi6 chdt lrr{ng crta hQ
Khi dQng co hoat dQng vdi bQ chinh lrru c6 didu khidn, ddng qua
ddng co kh6ng phdi ld hlng so, c0ng nhu ddng cria ngudn AC cung cdp
cho bQ bidn ddi crlng khdng phdi lA dang sin. Didu ndy dnh hu6ng ddn
chdt lrrong dr{p rl'ng cria hQ thdng vd 6nh hrrdng l6n ngu6n cung cdp. M6t
so thdng sd sau ddy thrrdng dnng dd d:inh giri chdt lrrong cria ddp rlng
cria tlQng cd, crlng nhu dnh hrr&ng cria hQ thdng l6n ngudn AC cung cri'p.
Cdc th,6ng sd d6.nh gid chdt
ltgttg
dd.p itng erta dQng co
Dic tinh co cria d6ng co.
2- Tinh chdt cria dbng di6n qua dQng co: li c6 thd li6n tuc hodc gidn
doan. Didu ndy 6nh hudng l6n dic tinh co vd drip rlng qu:i d0 cfia hQ
1-
th6'ng.
3- Dbng phdn f'ng trung binh Iu: Khi d6ng co hoat dQng vd,i bO bidn
rl6i, ddng phdn drrg trung binh ld:
tt +T
1 '-
1,=
." !TJ| i..
"
dt
(2.73)
l1
lrong d6: iu - dbng phdn fng trl'c thdi (bidn thidn theo t);
? - chu kj bidn thi6n cfia dbng phdn ttng iu.
Trong ddng co DC hich td d6c ldp, m6men dQng co sinh ra
rling phdn i:ng trung binh
fi
lA u6i
4- Dbng phdn rl'ng hi6u dung luh6: dugc cho bdi c6ng thf'c:
(2.r4)
NhiAt sinh ra trong phdn tng dQng co
fi
lA udi ddng phdn ttng hi\u
lqrng,
5- Ddng phdn rl'ng dinh ir-: Srr chuydn mach (gAy ra tia lfia diQn) d
cd g6p d6ng co DC phu thu6c vAo gi:i tri dinh cfia dbng phdn rfng.
Cda thdng sd a4c ttrtrg 6nh ht&ng erta hQ lhn ngu6n roaxr chi6u
oung edp
f - H€ sd c6ng sudt ng6 vdo cria bQ bidn tldi, pF, duoc dinh nghia:
PF=
C6ng sudt thuc ngd udo BBD (W)
(VA\
(2.L5)
CHUONG 2
Ndu di€n rip ng6 vdo ld d4ng sin khdng m6o, chi c6 thdnh phdn hAi
cd bAn cfia ddng ng6 vdo t4o ra cdng sudt & ngd ra cria BBD. Vi vQy, c6
thd vidt bidu thrlc tr6n nhu sau:
Vp .1r.cosg,
oo
_
Vp'Ip
trong d6: Vp - di€n rip pha higu dung d ng6 vio BBD;
Ip - dbng pha hiQu dung d ng6 vdo BBD;
I1 - gi6 tri hiQu dgng hdi cd ben cfia ddng ng6 vio BBD;
gr - B6c l€ch pha gif,a diQn dp ngd vdo vi hii co bdn cria
ng6 vAo BBD
2- HC sd m6o d4ng, TIJD (Total Ha.rmonic Distortion), dinh
nhu sau:
_Ih
THD =
Ir
THD gd = THD x 100
trong d6: In - gid tri hiQu dgng dbng hdi b4c n;
In - gi6 tri hiQu dgng tdng cria cdc ddng hdi.
Gqi i ld dbng tfc thdi ng6 vdo BBD, dbng ndy c6 thd phdn
thdnh hdi co bAn vd cdc hAi b{c cao theo phAn tich Fourier nhu sau:
r
= Io
trong
d6:
+ }r",cosnof +b, sinzco/)
n=l
Io
-
Qn=
bn=
In-
= Io +
\J-zt^sin(zot+g,)
Q.
otEu xut{u r6c oQ oQNa co M)r curEu
2.3.3
43
Di€n 6p ng6 ra b0 chinh luu d chd d0 ddng li6n tgc
- Chinh luu mQt pha brin s6ug cd di€u khien:
Vt"2n
=
o'"
\ lo17
11
+ cos cr)
(2.24)
trong dd: V.i - di€n dp trung binh ng6 ra b0 chinh lrru;
Vp - trl hiQu dung rip pha ngudn xoay chidu cung cdp cho b0
chinh lrru:
- g6c kich
- Chinh luu mOt pha cdu didu khi6n bdn phdn:
cr
vo
=
Evu1l+
cosa)
(2.25)
T,
- Chinh luu mQt pha cAu diiiu khi6n todu phdn:
vo
-
212v"
n
..o"o
(2.26)
- Chinh luu ba pha tia cd diiiu khi€n:
v,,
=
3J^6%
2n
"oio
(2.27)
- Chinh lur ba pha cdu didu khidn bdn phdn:
v,t
}'l:v"
= 2r (1+ cosu)
(2.28)
- Chinh lurr ba pha cdu didu khidn toAn phdn:
Yo
-
3J64
t(
"o"o
(2.2e)
Hi€n td{ng chuydn m4ch
Cric c6ng thrlc tinh diQn rip trung binh ng6 ra chinh lLtu c6 di6u
khidn fi (2.24) ddn Q.29) dua tr6n gid thidt ddng chinh luu <j, chd d0
li€n tuc vA srr chuydn mach giua cilc linh kiQn trong mach chinh lrru ld
trlc thdi. Trong thrrc td, do diQn khring tti.n cria mriy bidn'tip cung cdp
cho chinh luu, di6u khring duoug dAy vd dieu khring th6rn vdo mach
gCR dc bdo vQ linh kien (chdng dildt), stl chuy6n rnach girta c:ic linh
kiQu c6ng sudt (SCR, diode) trong mach chinh luu kh6ng di6n ra tf'c
thdi mi crAn mQt khoAng thdi gian nhd't dinh.
HQ quri cria hiQn tugng chuydn rnach ld di6n dp ng6 ra ctia chinh
S.2.4
44
CHUANG 2
- Vdi chinh lrru mgt pha cdu di6u khidn todn phdn:
Av"^=
ov, f
+
Q}oa.
- Vdi chinh lrru mQt pha cdu didu khidn b:in phdn:
vf
av",, =
2*
(2.30b.
- Vdi chinh lrru ba pha:
AV",,
= PX'Ia
(2.30c)
TC
-
Quan h9
gifa sut dp trung binh do chuydn mach vd gdc chuydn
m4ch p:
aV",n
v.
= jS(cosa-cos(u+p))
z'
(2.30d)
trong d6: p - sd ldn nhdp nh6 (s6'xung) cria diQn :ip chinh lu' trong
chu kj' dp lrrdi; & - diQn khring m6t pha cria ngudn;
^I.7 - dbng trung binh ngo ra ctia bQ chinh lrru;
V7, - diQn dp ra cuc dai cfia b6 chinh ltru (khi a = O):
p - g6c chuydn mach.
C6 thd vidt lai c6ng thrlc (8.19a) - (8.19c) drrdi dang:
mQ
R"^'Ia
(2
Di6n 6p trung binh ng6 ra cfia b6 chinh lw khi kd ddn hi6n tdc
chuydn mach lA: Vao = Va - AV"Ndu kd th6m diQn dp sut tr6n linh ki6n c6ng sudt trong mach chi
Irtu, di6n dp trung binh ng6 ra cia bQ chinh luu s6 ld:
Vao = Va - AV"*-- V7
trong d6: Vr - diQn rip sut tr6n linh ki6n.
Ngodi ra, d6'i vdi b0 chinh lur hoat dQng trong chd tlQ nghich
hiQn tuong chuydn mach ldm gi6m g6c kich tdi da cho ph6p cria b6
lrru. Khi kd ddn hicn tudng chuydn mach vd thdi gian tdt cria scR,
kich tdi da cho ph6p cria bQ chtnh lur ld:
0mu=tr-lt-o-6
trong d6: p-"* - g6c chuydn m4ch tdi da (rlngvd,i lal6n nhdt);
6 - g6c t6t cria SCR, rlng vdi thdi gian tdt cfia SCR
AV",n =
oEu rcnEN rdc oQ oQNa co MQr cuEu
45
- DONc cd
2.4 HE rHdNG s0 cHir,tH
LIJIJ
2.4.f DQng cd kich trl dQc
lfp hoat dQng vdi b0 chinh lrlu
Mach trrong drrong cria hQ thdng BCL-DC nhrr hinh 2.L6, trong d6 L
bao gdm di6n cdm phdn rlng vd diQn cim phu th6m vdo mach phdn rlng.
ll.
Hinh 2.76: HQ thdng b6 chlnh luu - d6ng
co
DC kich ttI d6c ldp
trinh bidu di6n quan h6 gitta cdc gid tri trlc
,,chlnh luu, sri'c diQn dgng dQng co vd ddng phAn fng ld:
Phuong
thdi cfia di6n :ip
,ud=Ru';r*fff+E
l,rong d6: ua,
ia
ld, cdc gi6
tri
(2.33)
trlc thdi cria iliQn rip chinh lrru vd ddng phdn
rhrg.
Luu y ld E duoc gid thidt kh6ng ildi theo thdi gian trong phrrong
i,rinh tr6n, do trong thuc t6'thudng g4p qurin tinh co cfia hQ thdng ldn
lron nhi€u so vdi qurin tfnh di6n tr] ndn t6'c d6 cl6ng co c6 thd xem ld
kh6ng
ddi.
L
d chd d6 xric I4p, tiy thu6c th6ng sd clQng cd, cd'u hinh b6 chinh luu,.
kich vd m6men tAi, ddng phrdn rlng cria d6ng co c6 thd li6n tuc hoic
jirln doan. 6 dnd d6 dbng gidn doq.n, d{c tinh co cria dQng co rdt ddc,
gdc
ttltu sE kh6o s:it d phdn sau trong muc nd.y. Th6m vho d6, trong thrrc td,
ttgay ci khi kh6ng tdi, ddng qua dQng co cfrng c6 m6t giri tri nd,o d6
(f,hrrdng khodng 5-7OVo Ia) do m6men ma sd.t lu6n c6 trong h6 thdng. Vi
vfly, vdi thdng sd tlQng co vd cdu hinh b0 bidn tldi cho trudc, c6 thd xrlc
rlirrh drroc cuQn khring cAn th6m vdo phdn fng dd al6m bAo d6ng co lu6n
lror;t dQng d chd d0 ddng li6n tuc vdi moi gi6 tri cfia dbng phAn rlng ldn
46
Trong chd d0 dbng tliQn li6n tgc, phrrong trinh dic tinh co cfia dQnl
co la:
vd
Ka
---lVI
R,/ r,
(Ka)z
(2.34
Quan hQ gitra t6'c d0 vd ddng phdn rlng ctia dQng co:
vd
R,t r
xo- 111' 'u
(2.35
Trong d6, tiy thuQc cdu hinh b0 chinh hnr, gi6 tri cria V2 theo 96r
kich cr tinh theo c6ng thrl'c cho trong muc 2.3.3 d tr6n. Khi kd ddn hiQr
tugng chuydn mach do diOn khring ngudn, Va trong c6ng thrlc (2.35) dugr
thay bXng Vao nhu trinh bdy trong muc 2.3.4.
Thay ddi g6c kich a tr] 0 ddn n, trong chd dO dbng li6n tr,rc, ta duot
mQt ho tldc tinh co cfia ddng co ld nhrlng drrdng thEng nXm song song
nhau trong n(ra b6n ph6i cfia mit ph&ng (a, I) do dbng diQn ng6 ra cria
cdu chinh lrru chl cho ph6p dAn theo mQt chi6u (xem hinh 2.L7).
d chd tlg ddng gi6n doan, bidu thrl'c (2.94) vd (2.35) khdng thd 4!
dung. Khi d6, quan hO gifra t6'c tlQ vd m6men (ho{c ddng di6n) thrrdng
phAi gi6i bing mdy tinh. Hinh 2.17 bidu di6n tldc tinh co cria mQt tlQni
cd DC kich trl tlQc ldp 2.2kW, 1500v/p, cdp diQn bdi mQt cdu chinh hfrt
mQt pha tlidu khidn todn phdn c6 cliQn 6p ngudn AC la 230V, 50H1,
Hinh 2.17 cho thdy d{c tinh co cfra tlQng co rdt ddc trong ving girin cloq4
vd hQ th6'ng thudng kh6ng thd ldm viQc dn dinh d ving ndy ndu
c6 cfic phuong phrip didu chinh dac biQt.
Vr)ng dbng di6n girin do4n c6 thd gi6m tli bing crich:
- Tdng sd pha cria bQ chlnh lrru (vi du: dDng cdu chinh lrru ba
thay vi chinh luu mQt pha)
- Tdng rliQn khring trong mach phdn trog (t'i du: th6m diQn
phu vdo mach phAn rl'ng).
Hinh 2.18 ld ddc tinh co cfia dQng co khrio sdt trong hinh
nhung hic ndy duoc cdp diQn tr) cdu chinh lrru ba pha tlidu khidn
phdn v6i ngudn AC ba pha/50H2 c6 diQn rip pha la 100VAC. Ndu so
vdi hinh 2.18, c6 thd thdy ving ddng gidn doan da gi6m di dring kd.
oEu rcnEN r6c oQ o2rva co MQr cutEu
47
n (vg/ph)
|
BiCn lien tuc
800
1
Bi6n li6 r tuc
z9l
r2ool\
04
i
46810
o2
-300
-€00
-o,2
-900
-1200
-0,4
10 12 14 16 18 20
M(Nm)
Hinh 2.77: Dd.c tinh co dQng co
tt dQc ldp ld.m uiQc udi
bQ chlnh luu m6t pha cdu didu
hhidn tod.n phdn
DC kich
-1 500
-1 800
Hinh 2.78: DQc tinh co d6ng co
DC ktch tt dQc ldp ldm uiAc udi
b6 ehlnh luu ba pha cdu didu
khidn todn phd.n
Hinh 2.19a,b ld ddc tinh co cria mQt d6ng co DC kfch til dOc l4p
zl(W, 1800v/p, Ru = 0,5O, cdp diQn tr} mdt cdu chinh luu mOt pha didu
khidn bdn phdn. Hinh 2.19a ld ddc tinh co cria clQng cd khi chi c6 diQn
klrdng phAn rtng (Lt = 6mH) trong mach phAn rlng. Hinh 2.19b ld ddc
I,irrh co cria dQng cd khi th6m diQn khdng phg Zp = 24rnH vdo mach phdn
rtrrg (tdng tli6n'khring mach phAn ring hic nAy ld 30mH). C6 thd thdy
virng ddng gidn doan trong hinh 2.19b gi6m di nhi6u so vdi hinh 2.19a.
Vdi b0 chinh lmr tli6u khidn toAn phdn, khi g6c kich bidn thi6n
vi 0 +gQo, b0 bidn ddi lAm viQc 6 chd dO chinh hnr vd dQng co
lilrrr vi6c d chdd0 dQng co (vdi E > 0) (H.2.20a), hoic ch6'd6 hdm ngugc
(r'i < 0). Tuy nhi6n, d chd ctQ hdm ngudc, hi6u sudt cria hQ thdng rdt k6m
rr0n it khi sfi dung. Vdi g6c kich > 90o, ndu cuc tinh c0a SDD tldng co
rf rtrlc d6o chi6u: E < 0 vd lE l>lvd | , nhu hinh 2.20b, dQng co sE ldm viQc
rt r.hd d0 hdm tdi sinh. Lric nAy, bQ chlnh lrru ldm vi6c d chd dQ nghich
lrnr, chuydn ndng lrrong tt dQng co v6 ludi diQn.
Srlc diQn dQng cria dQng co trong tnrdng hop h6m tdi sinh nhu tr6n
t,hd
lr1
drroc tlAo chidu blng cdch:
- DQng cd mang tAi c6 tinh thd ndng ldm dQng co quay ngudc.
I
r'rurg pham
- Ddo chidu kich tU dQng co.
- DAo chidu phdn rlng dQng co.
CHUONG 2
48
1,0
0,9
0,8
o,7
0,6
I
i
0,5
0,4
0,3
0,2
a)o
0,1
i'
a=30o
10 msec
' o 2 4 6 I 101214
c=Oo
Hinh 2.19: Ddc tinh co dQng co DC ktch til dQc IQp ld'rn viQc
vdi bQ chtnh tttu mQt pha didu khidn bdn phdn
'a) Mg'ch phdn tng chl c6 Ln
Ru = 0,6d), Lu=
6mH;
VQn tdc n*:
""
=tr\
l"*^
b) Mqch phdn tXng c6 thAm diQn khdng phry Lp = 24mH
Ru = 0,6d1
Lu= 6rnH; VQn t6c
n*: n'
)
otEu xurEN rdc o0 oQxa co MOr cutEu
49
l;
t:
0sa<90ovAVa>E
Hinh
90o<a<180o vAlvdl <lEl
ldm uiAc crta dQng co DC
u6i b0 chlnh luu diAu khidn tod.n phdn
a) Chd dQ dQng co; b) Chd d6 hd,m tdi sinh
vdi b0 chlnh ltnr tlidu khidn bdn phdn, h6m t6i sinh kh6ng thd thr.rc
hiQn do diQn dp ra cfia b9 chlnh hnr kh6ng thd dao chidu. Do d6, dic tinh
co cfia hQ thdng chl nlm trong phdn trr thrt I cria mdt phEng d{c tinh co.
2.4.2DQng cd kich trl ndi ti6p hoat dQng vdi b0 chtnh lrru
Hinh 2.21 bidu di6n dQng co kich tr] n6'i ti6p dugc cung cdp tt bQ
chlnh luu c6 didu khidn.
2.2O: Cdc chd dQ
l!.
L=Lu+Ln+l-p
Hinh 2.27: HQ thiing
N6'u b6 qua
til
bQ
Rr = Ru+ Rn
chlnh luu - dQng
co
DC kich
du cria dQng co, quan hQ gitra
tt
ttX
ndi tidp
th6ng vd dbng phdn
thrg ld:
.
(D
= Ka,. i,r
M6men trlc thdi ctia dQng co lA:
rn = K.(0. ir1= K.KH.
(2.36)
i|
(2.37)
Mdmen trung binh do dQng co sinh ra:
M=K
=
"r,lljU.,l
\- o
)
K.Kyt.rSna
VSy, m6men do dQng co kich tr} ndi tidp sinh ra
(2.38)
tl
lQ vdi binh
CHUONG 2
fng dti ld,n ttd c6 thd b6 qua nhdp nhd cria ddng phdn rfng,
thi: f, -- Ina.Khi tl6, momen dQng co s6 tl lQ vdi binh phrrong cria
phdn rlng trung binh. Lric ndy, d{c tinh co ctia dQng co c6 thd suy ra
cOng thrlc (2.9) ho4c (2.10), trong d6, gid trf cria V drroc thay blng tli
mAch phdn
dp trung binh ng6 ra va (ho4c v6o, ndu kd ddn hiQn trrong chuydn mac
cfia bQ chinh lrrrr, tly thuQc vdo cdu hinh chinh hnr sir dgng'
vdi hc thdng b0 chinh ltnr - tlQng cd DC kich tir ndi tic'p, dbng tli
phdn rlng c6 thd 6 chd d0 li€n tgc trong mqt ddi rQng cria d{c tinh co.
thd giai thich didu nay ndu lur f rhng sfc diQn tlQng cfia dQng co
kich tir nO'i tidp tl Ie vdi dbng phdn ring (gi6 thidt tdc dQ dong co
kh6ng ddi). Khi momen t6i giam, dbng phdn fng giam trlong rlng,
rldn sfc diQn dQng crla dQng co gi6m theo vd do d6, Idm cho dbng diQn
thd tidp tgc duy
tri d chd dQ li6n tuc.
H\nh 2.22 bidu di6n tl{c tinh co cfia tlQng co DC kich tir n6'i
l,bkw, 110V, 1800v/p, cung cdp bdi cdu chlnh lrnr mQt pha {lidu khi
toin phdn (tlrrdng n6t lidn) vd bdn phdn (tlrrdng n6t drrt), vdi giA thidt
dbng phAn rlng li6n tuc vd Ph&ng.
n (vg/ph)
3000
2800
2600
Cdu 1 pha didu khidn hoin toAn
Cdu 1 pha didu khidn b6n Phdn
2400
2200
2000
1800
1600
1400
1200
1000
800
600
400
200
o2468101214161820
M(Nm)
Hinh 2.22: DQc tinh co dQng co DC kich til ndi tiilp
chlnh luu 3
otEu xutEN rdc oQ oQxo co Mer cutEu
51
2.5 HE rH0NG s0 CHil'tH LUU - DoNG Cd C6 sAO CntEU
Khi hoat ddng vdi bQ chtnh hnr didu khidn todn phAn, hQ thdng c6
thd ldm vi6c trong phdn tu I va IV, nghia ld d chd dQ dQng co theo chidu
thuQn vd hdm tdi sinh theo chidu ngugc lai. Dd c6 thd ldm viQc d c6 bdn
phdn trr cria mdt ph8ng tl4c tinh cd, c6 thd srl dung c6c phuong phdp:
1- D6o chidu dbng phdn rhg;
2- DAo chidu ddng kfch til.
2.5.1
Dio chiiu ddng phdn rftrg
viQc d6o chidu ddng phdn ring c6 thd thrrc hiQn v6i c6c so dd khdc
nhau nhrt chi ra tr6n hinh 2.23.
B9 chlnh
ldt
aoi eontqat d.6o ehi6u
C6 so dd nguy6n lf nhu hinh 2.28a, trong d6 dQng co duoc cdp diQn
til mQt cdu chlnh lur tlidu khidn todn phdn qua mQt bQ contact d6o chidu
TN. Muc dich cria bQ contact dao chidu TN la d6o chidu dbng qua dQng co
so vdi chidu ddng diQn qua bQ ehtnh trru. cdc contact d6o chidu ndy c6
thd ding tidp didm co khi nhrr hinh 2.28b hoic brin dan nhu hinh 2.28c.
ViQc dAo chidu drroc thrrc hi€n vdi ddng phdn rlng blng zero tld
t,rdnh c6c xung dp c6 thd sinh ra do tdi d6ng co c6 tinh c6m kh6ng.
l)dng phdn rl'ng duoc drra vd zero blng c6ch ttrng g6c kfch r6n mri'c cao
rrhdt, sau al6 ngrrng kich xung cho BCL khi dbng blng zero. Sau khi Iu= O,
rnQt khoang thdi gian tr6 tt 2-10ms duoc th6m vio trudc khi bO contact
rldo chi6u TN tdc d6ng nhXm d6m bao srr chuydn mach di6n ra khi ddng
lrlrdn rrng d.e t6t hodn todn.
Sau khi viQc chuydn m4ch d6 hoAn tdt, xung kich drroc dua trd lai
llOL vdi g6c kich ban ddu ld ldn nhdt vd sau d6 duoc gidm ddn. DQng co,
rkr d6, ltic tldu s€ hoat d6ng d chd dE h6m t6i sinh khidn tdc d0 gi6m ddn
vd zero sau d6 drroc tdng t6'c theo chidu nguoc lai cho ddn t6'c dQ ldm viQc
dn dinh.
HQ thdng thudng ttrroc thidt kd vdi vbng hdi tidp ddng rliQn
hqn chd ddng phdn ,lng d mrlc cho ph6p trong qud trinh qud dO.
nhlm
Khuydt didm ldn nhdt cfia sd dd hinh 2.28b ln d6p rtng qud dQ
rh{m. Ndu st dgng contact TN ld tiCp didm contactor, cdn lrru f ld thdi
ginn d6p rl'ng cria mQt contactor cd 50-1p0ms. Ngodi ra, cdn tinh tdi
CHUONG 2
contact TN di6n ra khi ddng -I, = 0. Do giri thdnh 16, phuong phdp ndy
drroc dilng vdi nhfrng truy6n dQng diQn c6ng sudt thdp, kh6ng tldi h6i
tldp rlng nhanh.
Vdi so tld hinh 2.23c, chdt luong ddp rlng qu6 d0 c6 thd c6i thiQn
ddng kd, tuy nhi€n gi5 thdnh cria hQ th0'ng cflng cao hon do cAn c6 th6m
mach didu khidn cho cdc kh6a b6n dAn.
A
l"
lr
ZN
i
j
\
\
Hinh 2.23: Ctic so d6 dd,o chidu ddng phdn tng
a) Chinh luu don udi chuydn mqch; b) Chuydn rngch,tieip didm
c) Chuydn mach bdn ddn; d) Chlnh luu kLp didu khidn rizng
e) Chlnh htu kdp didu khidn chung
chlnh ldu kbp
Bao gdm hai b0 chlnh lur tlidu khidn toAn phdn mdc song so
ngugc (antiparalell) nhu hinh 2.23d, e. N€u bQ chtnh lur 1 cho ph6p
cd hoat dQng 6 phdn trr I vd IV, b0 chlnh ltnr 2 s6 cho ph6p tlQng co
dOng 6 phdn tu II vd III. BO chinh hnr k6p c6 thd ho4t clQng
phrrong phdp didu khidn ri6ng (H.2.23d) ho{c didu khidn ch
(H.2.23e). Vdi BCL k6p tli6u khidn ri6ng, tai mQt thdi didm chi cho
mQt BCL hoat dQng cbn b0 kia I trang th6i kh6a (kh6ng c6 xung kfch).
BCL k6p diiu khidn chung, cA hai b0 chtnh lnr ho4t clQng ddng thdi, mQt
chd ttQ chtnh lur vd bQ cbn lai & chd dQ nghich lutr.
BQ
orEu t<urflw
rdc oQ oeuo cd
MOr
cuEu
ehlnh ltu hdp d.idu hhidn riOng
Gia thict bQ chinh lrru 1 dang hoat dQng d chd dQ chinh lurr, khi d6,
xung kfch vdi g6c kfch a, dudc drra tdi BcLl, cdn BCL2 s6 d trang thrii
kh6a. Dd drio chi6u, dQng co cdn drroc didu khidn dd lam viQc d g6c phdn
tu II (chd d0 hem t:ii sinh), sau d6 chuydn dan l6n phdn tu III (chd do
d6ng co). Dd thrrc hien didu ndy, vi6c cung cdp diQn cho dQng co can
chuydn tr] BcLl sang BCL2. Trrrdc khi BCL2 duoc kich, tdt ca c:ic scR
cfia BCL1 phii d tr4ng t]^6i #r dd trrinh su ng6n mach ngudn c6 thd xdy
BQ
ra.
Trinh tu chuydn mach duoc thrrc hi6n theo
c6c brrdc sau;
- Dbng phdn r1'ng duoc gidm vd zero bhng crich ting g6c kich cr1 ddn
mfc cao nhdt
- sau khi nhan bidt ddng phdn ri'ng dd v6 zero (qua crim bidn ddng),
rn6t khodng tr6 2-10ms drroc duy tri. Trong khoing thdi gian ndy, xung
kich ddn cri hai BCL ddu bi ngdt.
- sau d6, drra xung kich ddn BCL2 v6i g6c kich a2 sao cho hQ th6'ng
hoat dQng d chd d6 h6m trii sinh vdi ddng cli6n d mfc cao nhdt cho ph6p
rtd quri trinh hdm xdy ra nhanh nhdt. G6c kich c2 s6 duoc giim ddn
cho
rldn khi d6ng co dio chidu vd hoat d6ng dn dinh d chc'116 d6ng co vdi
chi6u quay ngrroc lai.
vdi b0 chinh lrr'k6p didu khidn ri6ng, vi6c do ddng phdn d'ng chinh
xdc dd dam brio chxc chin ddng d, hodn todn bXng zero trrrdc khi chuydn
rnach gifra hai bQ chinh lrru la rat quan trong dd trrinh vi6c ng6n mach
ngudn do SCR d c6 hai bQ chinh lrru ddu dAn.
chinh
ltu
hbp di6u hhidn ehung
Trong b6 chinh hnr k6p di6u khidn chung, xung kfch drroc drra tdi c6
Itai b6 chinh lrru nhtrng vdi g6c kich kh:ic nhau, sao iho tdng diQn rip DC
cria hai bQ chinh luu la zero dd kh6ng c6 dbng DC chay m6c vdng trong
hni bd chinh lrrr.r. Do d6:
BQ
Vai.1
i
Vao COS%,1
-
*
+Va2=Q
Vao COS%2
COSUI
=
Q
+ CoSd2 = 0
+ al+dz=780"
(2.3e)
CHUONG 2
64
cdc chd dO khdc nhau, diQn dp tf'c thdi d ng6 ra cfia chfng kh6c nhau,
d6n ddn c6 ddng cdn blng xoay chidu ch4y vdng trong hai b0 chlnh lrru.
Dd gi6m ddng c6n bhng, cuQn kh:ing cAn blng L1 vd L2 phili duoc th6m
vdo mach chinh lur nhrr hinh 2'23e. Nhu v$y, m{c dt cri hai BCL ddu
hoqt dQng, khi dOng cd dang Iim viQc theo mQt chi6u ndo il6 thi chl c6
mQt BCL cung cdp dbng cho phdn ring dQng co, cbn BCL kid chl tAi
dbng cdn blng.
Qu:i trinh d6o chidu tlQng co di6n ra nhu sau: giA sfi ban ddu dQng
cd ho+t dQng theo chidu thu{n (g6c phAn tu I) vdi BCL1 d chd clo chtnh
lUr. Khi dio chidu, g6c kich cr1 sE dugc tdng l6n vd cr2 gi6m di theo quan
hC (2.39). Srlc diQn clQng E cria dQng cd se ldn hon lVar I vd lV62l, n6n
tlQng co ho4t dQng E chd clQ hdm tdi sinh d g6c phdn tu U. Ddng phan
rlng lric ndy do BCL2 cung cdp. Vi cr2 drtoc girim ddn n6n dQng co giAm
tdc, sau d6 tdng tdc theo chidu nguoc lai cho tldn khi dat tdc d0 dn dinh.
Trong qud trinh ndy, ddng dQng co duoc gi8 d mrl'c gidi han eho ph6p
nhd mach vbng didu khidn ddng tliQn nhu hinh 2.24.
t
t,
I'i
lr
Hinh 2.24: So d6 hhdi phdn didu khidn b6 chlnh luu kdp
hidu didu khidn chung
khidn chung c6 mach tli6u khidn don
hon kidu tlidu khidn ri6ng. Ddng diQn phAn rlng dQng co c6 thd ddo
BQ chinh lrru k6p tlidu
c
ll
F
h
otEu xutEr,t r6c oQ oQNa co MQr cuEu
oc
khidn hG thdng trd n6n cdng k6nh, tdng giri thdnh, gi6m hiQu sudt va ha
sd c6ng sudt. Drip fng quri d0 trd n6n ch{m di do thdi h}ng phdn fng
tlng thdm.
2.5.2D6o chiiu kich
trl
Hinh 2.25 trinh bAy sd tld d6o chidu quay dQng co bhng c:lch d6o
chi6u kich tt. Ddng kich tir d6ng co c6 thd dAo chidu dnng b0 bidn ddi
k6p (H.Z.ZSa) hodc vdi b0 contact ddo chidu (H.2.25b). Ndu rtng vdi m6t
chidu cfia ddng kich tr}, dQng cd ldm viQc d phdn trr thrl I vd thrl IV, chidu
ngugc lai cria ddng kich tU sE tudng rl'ng vdi ving ldm viQc cria tlQng co d
g6c phdn
tu
thf III
vd
II. Vi ddng kich tU thrrdng nh6 hon rdt
nhidu so
vdi ddng phdn rlng, cdng suA't cria b9 didu khidn d6o chi6u clng nh6 hon,
vA do d6 giri thdnh s6 thdp hon nhidu.
EUL pnan ung
CKT
f
+
+
+
BCL kich
td
I
BCL kich td 2
kich til dQng co DC
a) Ding bQ bidn ddi k4p; U Dnng contact ddo chiau
Hinh 2.25:
Dd,o chidu
Tuy nhi6n, do thdi hing ldn cria cuQn kich tt, viQc d6o chidu ddng
kfch til s6 diSn ra trong thdi gian ddi hon nhidu so vdi qud trinh dio
lhidu ddng phdn fng. Ngodi ra, trong quri trinh d6o chidu ddng kich tt,
r,drr gitr ddng phdn ring bXng zero dd tr:inh 6nh hudng xdu cria diQn dp
trlrn rlng l6n vi6c chuydn mach d cd g6p dQng co. Didu ndy khidn m6men
rlQng co blng zero trong qud trinh dio chidu ddng kich tt vi cdng ldm
illng thOm thdi gian qud d0 cria h€ th6'ng. Vi v4y, dD gid thdnh thdp,
phuong phdp ndy it khi drrgc sfi dung, trit trrrdng hgp rlng dung cho cdc
lr$ thdng cdng sudt ldn vdi mdmen qurin tinh cao. Khi d6, do thdi hlng
nrl cfia he th6'ng ldn hon nhidu so vdi thdi hlng kich trl vA quydt dinh
CHUONG 2
cdc budc sau:
:
Teng g6c kich cfia b0 chinh hlu cung cdp cho phdn rtng l6n cao
nhdt dd dbng phdn ri'ng v6 zero.
- Ttrng g6c kich cfia bQ chinh lrru dang cung cdp cho kich tir l6n cao
nhdt dd ddng kich tt vd zero.
- Sau mQt khoing tr6 thich hgp, b0 chinh lft thf hai dtroc kich vdi
g6c kich thdp nh6t tld tldy nhanh quri trinh x:ic l4p cria ddng kich
theo chi6u ngrroc lai.
- Khi dbng kich tir dn dinh gdn dat gi:l tri xrlc l{p vd sri'c diQn
phdn rfng dd tl6o chi6u, bQ chinh ltnr cung cdp cho phdn r1'ng duoc
vdi g6c ldn nhdt dd dQne cd ham trii sinh. Sau c16, g6c kfch ndy d
gi6m ddn cho tdi khi dQng cd ldm viQc dn tlinh d t6'c ilQ lim viQc
theo chi6u nguoc lai.
2.6 B0 slEN o0r xuNc Ae
1- BQ Chopper
puoeeml
hidu gi&.m 6p (Chopper l6p A)
Hinh 2.26a 86 chopper kidu gidm dp (Chopper ldp A)
120,O0
100,00
80,00
60,o0
40,o0
20,o0
0,00
-20.00
ld
't
6,00
15,00
11,00
13.00
r2,00
1t,00
oAu xnEN rdc oO o1trc co Mor cutEu
DT
Hinh 2.26a trinh bAy so dd nguy6n ly cria bQ chopper kidu giAm rip.
Hinh 2.26b ld dang s6ng ng6 ra cfia b6 chopper loai ndy. Kh6a bdn d6n
S c6 thd ding cric linh ki6n di€n tfi c6ng sudt khric nhau nhrr thyristor
vA. mach t6t, GTO, MOSFET, transistor c6ng sudt ...
DiQn rip trung binh ngd ra cfia bd chopper kidu gi6m dp tinh theo
cdng thri'c:
va=
trong dd: y =
+-
-T
-^F
(2.40)
= +!roat=yv
|Juaat
00
(2.40a)
hO sd di6u chinh;
V - di6n :lp ngu6n DC cung cdp cho bg chopper.
Bing crich di6u khidn y trong khoAng 0 -+ 1, di6n rip tdi c6 thd bidn
l,hi6n trong khodng 0 -+ V.
Cdc phrrong phdp diriu khidn kh6a S c6 thd chia
lim hai loai:
- Didu khidn ti lC thdi gian (time ratio control)
- Didu khidn ddng (czrrent limit control)
Phuong phrip di6u khidn ti 16 thdi gian c6 thd chia ldm hai crich:
Td,n sd cd dinh: chu k! tl6ng cdt ? kh6ng ddi, thdi gian d6n ton Lhay
rl.ii dd thay ddi y .
Tdn sd thay ddi: y thay ddi bing crich gifr ton cd dinh vd thay ddi ?
lrrrrlc bXng crich thay ddi ci to, vd, T.
Vdi phuong ph6p thay ddi y bing crich girl to,, c6 dinh, tAn sO' d6ng
lt{l sc rdt thdp ndu cdn dat di6n rip ra V6 nh6. Tdn sd d6ng cdt thdp cria
lrr) chopper s6 rinh hrrdng kh6ng tdt dCn cl6c tinh dQng co. Ngodi ra, vi6c
lhrry ddi tdn sdhoat dQng ctia bQ chopper s6 gdy kh6 khnn cho vi6c thidt
hn rnach loc ng6 vAo ctia bQ chopper. Do d6, phuong phdp thay ddi tdn sd
tl khi duoc sfi dung.
Vdi phuong phdp dieu khidn dbng, 1 tlrroc di6u khidn gi:in tidp bhng
lrfi'h di6u khidn dbng tAi bidn thi6n gifra hai giri tri gidi han tr6n vd
rhtrli quanh giri tri ddng tdi cdn thidt. Thdi gian ON vd OFF cria kh6a S
rlrlr,tt: thay ddi mQt c:ich trr dQng. Khi dbng t6i gi6m ddn giri tri gidi han
drtrfi, kh6a S drroc kich ddn (ON), tai drroc ndi vdi ngurin vd dbng tdng
16rr. Khi ddng trii tfng ddn gi:i tri max ddt trudc, kh6a S tlrroc kfch tdt
cfia
s
cdng ttrng cao. Loi didm cfia phrrong phdp ndy ld didu khidn
ti6p ddng tai, do d6 c6 thd thict kd dd tr:inh cluoc hiQn trrong ddng
doan.
Tt
dang s6ng dbng d hinh 2.26, nhitng vdn dd quan trgng sau
lur f khi thidt kdvd sf dung bQ chopper:
1- Dbng ngudn c6 dang xung, vA do d6, c6 thd gAy ra dao dQng
lrrdi di6n cung cdp ndu bi6n dQ xung ddng niy ldn.
D+ng s6ng ng6 vdo bQ chopper c6 thd phAn tich thAnh thdnh
DC vd cdc thdnh phdn ddng hdi. Hdi co brin cria s6ng hii ddng
c6
s6'blng tdn s6'd6ng ngdt cria b6 chopper. s6ng hai ddng c6 thd g6y
nhi5u tron ceic thi61 bi sfr dung chung ngudn tliOn lud,i vdi bQ chr
hodc c6 thd sinh ra bti'c xa nhi6u cli€n tr]. Do d6, mach loc L-c
th
duoc s& dung d ng6 vdo bQ chopper dd han chd s6ng hdi sinh ra
tr6n
r
cung cdp cho bQ chopper.
Tdn s6'tl6ng ngdt cria b6 chopper cdng cao, mach loc cdn thi€t
nh6. Do d6 non cho b6 chopper lim viQc vdi tdn sd d6ng ng6t cao
c6 thd duoc.
ca
2- Di6n zip cung cdp cho d6ng co c6 dang xung vd do d6, bao
thdnh phdn DC vd cdc hdi bac cao c6 tdn sd ld boi tdn cfia tdn s6'
ng6t cria bQ chopper.
S6ng hdi trong ddng
tri y xdc dinh,
trii, vA tUdng rlng ld don s6ng ddng, tai mQt
phu thu6c vdo tdn sd d6ng c{t cria b6 chopper vd di
khring tai. D0 don s6ng ddng c6 rinh hu6ng ddn chdt lrrgng dr{p rlrrs
dQng co. Don s6ng dbng s6 gi6m xu6'ng khi tdng tdn s6'd6ng
cdt I
tdng di6n khring t6i. Do d6, thrrdng cho chopper vdi tdn so. ddng cdt
nhdt c6 thd duoc, sau d6, ndu dQ don s6ng dbng v6n ldn hon mfc
ph6p thi mdi cdn th6m cliQn khdng phu vdo mach t6i.
2- BQ ehopper kidu tdng 6p (Chopper l6p B)
86 chopper kidu tdng 6p c6 so d6 nguyGn lf nhu hinh 2.22a. Da
s6ng ng6 ra cfia bQ chopper niy trinh bdy tr6n hinh 2.22b.
Tq C
song song vdi t6i nhlm gi6m don s6ng tliQn dp tr6n t6i vn gi6m
xung diOn 6p cao sinh ra tr6n L khi d6ng c{t kh6a b6n d6n S.
Gia thidt tu c dri ld'n dd diQn dp tr6n tu la kh6ng ddi trong
.
trinh d6ng cdt khria K, diQn rrp trung binh tai hai didm a-b rd:
-,-
Ctlu xnEu rdc oQ oQxe co MOr cutEu
.T
Vob=
) fr!u"tat
isLa
= Va(l
-
(2.47)
y)
1".
5,00
4,00
3,00
2,00
1,00
0,00
Vao
300.00
250,00
200,00
'!50,00
100,00
50,00
0,00
ts
120,00
100,00
8b,00
60,00
40,00
20,00
0,00
385,00
380,00
390,00
395,00
400,00
Hinh 2.27: 86 chopper kidu td.ng dp (Chopper I6p B)
a) So dd nguyAn
l!;
b) Dqng s6ng
Di6n dp trung binh tr6n cuQn cAm Z:
v"=
-T
,.
-T
!lo!>at
rJo dt =!ltat=
TJo
o
(2.42)
DiQn rip ngudn:
V=Vt+Voa
Thay (2.42) vd (2.41) vdo (2.43), ta dtroc:
V=Va,t_r,
V
(2.43)
Theo c6ng thtc (2.44), diQn 6p trung binh ng6 ra c6 thd thay ddl
ddn - khi y thay ddi t'I 0 -+ 1. Trong thuc td, phu thuQc vdo gid tri c
tu c vd th6ng sd cfia tdi cfng nhrr b6 chopper, gi:i tri cta v6 c6 thd
ildi tU V ddn mQt giri tri cao hon.
v
BQ chopper kidu tdng rip drloc dr)ng trong cdc xe di6n chay
accu c6 c6ng sud't thdp (stt dung tr6n san golf, trong c6c ctta hdng,
xudng...). Trong cdc Ong dung ndy, dQng co DC duoc cung cdp tir
ngu6n diQn rip thdp (accu) qua b6 chopper ldp B. Nguy6n lj cria
chopper kidu tdng rip cflng duoc ding trong bQ chopper c6 thd hoat
drroc 6 ch6'dE hdm trii sinh.
2.7 HE rHdNc B0 cHoppER - DONc cd Dc 0 ctrd s0 s0ruc cd
L He thdng
hich tt dQc tep
kich trf dQc lAp c6 so dd nguy6n
nhu hinh 2.28a. Hinh 2.28b ld so tld tudng drrong cia mach hinh
trong hai chd dQ: s dan vd s tdt. Hinh 2.2gc m6 td dang dbng vd rip
d6ng co trong chd d6 x:lc ldp vd ddng phdn fng ld li6n tuc.
bQ Chopper - dQng co DC
HQ th6'ng bQ chopper-dQng co DC
ViQc giai thich hoat d6ng cria mach hinh 2.2ga dtatrOn c6c gie
thidt
- Mach loc L-C dnng dd gi6m nhdp nh6 cria rip vd ddng ng6 vdo
chopper. Ndu gi6 thidt b6 qua tdn hao tr6n mach loc va tu c dfi
diAn dp ngd udo bd chopper c6 thd gid thidt hh6ng ddi ud bdng V.
- Tny thu6c di6n cim mach phdn fng vd tdn s6. hoat dQng cria
chopper, ddng qua d6ng co c6 thd d chd d6 li6n tuc hodc girin doan.
nhi6n, vdi cdc linh kiQn bdn dan hiQn nay, bQ chopper c6 thd hoat
6 tdn sd dfi cao dd ddng d6ng co lu6n ld li6n tuc d chd d6 hoat dQng
thrrdng. chd d0 ddng girin doan lfc ndy chi c6 thd xd.y ra d giai doan
d0. Do d6, ndu khao srit d chd dQ xric lap nhu tidn hdnh d drrdi ddy,
Lhd gid. thidt ld ddng d6ng co lu6n liAn tuc.
Trong khodng S d6n (0 < t S y'I), ta c6 phuong trinh bidu di6n
phdn fng:
d;
R,.i,+2,,# +E=V
gtttt nmEN rdc oQ
F.
oQrua
co uQr cuEu
61
1".
a)
s
dAn
t..
'ru,oo
80,00
55,00
30,00
5.00
''u
L.r
!
I!2
12,OO
1
)E
Iut
1,00
10,00
9,00
--
7,00
1480,00
s t5t
1
48s,00
1490,00
c)
vd
lll
R,
80,00
55,00
30,00
5,00
-20,00
L,J
40,00
30,00
20,00
E
10,00
0,00
-t0
b)
b)
00
1400,00
t410,oo
.|42O,OO t43O,0O
144O,OO
d)
'45O,OO
148O,OO
Hinh 2.28
b) So d6 tuong duong; c) Ddng iu liAn
h!c; d.) Ddng iu gidn doan
Trong khodng S tdt (y'I < t < T), ta c6 phrrong trinh bidu
di6n mach
phdn rhg:
Ru.iu+L,*+E=o
(2.46)
l.rongd6:t'=t-t
Giai hc phuong trinh vi ph6n tr6n vd'i lurr j rrng 6 chd
dQ xdc lap,
a
bdt ddu qud trinh S tdt, ta tfnh duoc bidu thfc
cria iufl). Ti d6, cd
Ip tr6n hinh 2.2ge duoc tinh theo bidu thfc:
suy ra ddng.Irl vd
trong d6:
Don s6ng ddng di6n Aio drroc tfnh bdi c6ng
thrlc sau:
V (L+ert'n-stttu
61,,=Iuz-Iut -r4-lT)
--u"i-v)Ttt,,\
2 Ndu
ti
A
"o' rt
rdt b6,nghia le ? <<
lut r'
hay
- - tu,
*rr1,
ttt
,,
trong d6
ld tdn sd d6ng ngdt cfia kh6a S, bidu thrlc (g.88)
c6 thd tinh gdn dring:
/J
v v.r_v\
L1r=fozlcJ-=
-T)
,: = ,f"-4T(1
DQ don s6ng ddng
dat crlc dai khi
Aigrro =
v
T
Q
= 0,5, khi d6:
8f"*L,
DiQn dp trung binh ng6 ra bQ chopper
Ddng phdn rlng trung binh:
tinh theo bidu thrlc (8.29).
yv-E
\,-Ru
Vi tir th6ng dong
co ld kh6ng ddi, m6men dQng co sinh
ra chl
thu6c vdo thdnh phdn trung binh ctia ddng phdn
rtng: M = K@I,r.
Th6ng thrrdng, ddng kh6ng trii cria dQng
co trong hQ th6,ng
d6ng di6n c6 m6t gid trf nhdt dinh I* ndo
d6. Dd dQng co ldm vi6c
chinh vdi moi t6i, cdn chon di6n c6m mach phdn
:ldtsd16].didu
tdn
d6ng cdt f* sao cho I* > Ai**.
2' EQ thdng bQ chopper - dQng ed Dc hieh
ttx n6i ti6p
Khi gidi thich hoat rlQng cfia dQng co DC kfch trl
n6'i ti6p cdn
ddn quan ho phi tuydn, do srr b6o hda cfia
d4c tfnh trl h6a, gifra tir
r
otEu xutEN
rdc o0
o2t'to co
M)r cutEu
rg b6o hda cria d{c tuydn trl h6a phu thuQc vdo gid tri trung binh .I, cfia
rlbng phdn fng. Khi d6, quan hQ gira srlc diQn dQng, dbng diQn vd tdc dQ
c0a dQng co
li:
E=K.o.or= ftI).a=K^.o)
(2.53)
Gid tri c&a K^ tinh duoc tr} ddc tinh tir h6a cria dQng co. Dic tinh tr]
h6a ndy c6 thd tlrrgc nhd sdn xudt dQng co cho drrdi dang b6ng ho4c dd
thi, hodc ciing c6 thd nh{n dugc qua thi nghiQm tru. c tidp tr6n dQng co
cdn kh6o sdt.
Ngodi ra, ciing gi6 thidt d drny ld tdn sd bE chopper c6 thd chon dri
ldn dd dbng qua clQng co lu6n li6n tuc. Khi d6, phrrong trinh d{c tinh co
cria dQng cd DC kich trl ndi tidp hoat dQng vdi b0 bidn tldi chopper li:
(2.54)
Vdi mQt gid
trinh tr,t sau:
tri
y, dac tinh co cria hQ thdng c6 thd
tinh
drroc theo
- Cho trudc /r,'
- Tinh I'r.- tU d4c tinh tr] h6a cria dQng co;
- Tinh to tt c6ng th(tc (2.54);
- Tinh m6men tU cdng thtc: M = KQIu -- K* In
Vi dU 2.10 trinh bdy cdch tfnh to:in hoat dQng cria mQt dQng co DC
kich til ndi tidp vdi b0 chopper.
z.s HE rHdNG s0 cHoppeR - D0Nc cd Dc 0
cnfs0 nAn TAt stNH
thdng bQ Chopper - dQng eo DC hieh til d.Qe lQ.p
BQ chopper kidu tlng dp (Chopper ld'p B) drroc srl dqng dd cung cdp
cho dQng co DC d chd tlQ ham tdi sinh. So tld tudng drrong cria hQ thdng
ndy trinh bAy tr6n hinh 2.29a, dang s6ng diQn 6p vd ddng tlQng co tr€n
hinh 2.29b.
DiQn cim mach phdn tng Lu lfc ndy d6ng vai trb nhu cuQn cdrr Z
trong m4ch h\nh 2.27a. Mach loc L-C tr6n hinh 2.29a c6 tdc dung loc cdc
nhdp nh6 cria diQn rip vA dbng ngudn. Tu C, ngodi ra, cdn c6 tdc dgng
tao dudng d6n cho ddng phAn rlng trong khoAng thdi gian kh6a S t{t,
trdnh c6c xung 6p edy ra do sq thay tldi dQt ngQt "dbng.{iQn qua L. Do
1- HQ
.LA*
(-^n^-^-^t-)
7
110
r20
la
'|
R
D
c
0
E4
L
s
00
80
60
40
20
83
1",
E2
8l
80
a)
990
vd
140.00
120.00
1 00.00
s0.00
60.00
40.00
20.00
50.00
40.00
30.00
20.00
10.00
0.00
-r0.00
910,00 920,00 93o,OO 94o,OO 95o.OO
900,00
Chd d0 dong gidn do4n
b)
Hinh 2'29: HQ thdng b6 chopper ' dQng co DC kich td itQc ta.p rdm uiac
chd d6 hdm tdi sinh
a) So d6 nguy|n t! hQ thdng; b) Dqng s6ng ddng, dp d ng6 ra
b6 c
trinh vi phAn bidu di6n hoat d6ng cfia h6:
Trong hhodng trt nd.ng lttqng (0 < t <
lI,), kh6a S d6n,
Phuong
fng chay qua S:
dbng
s;
dt
Ruiu+Lu7=E
i,/ (O) =
I,/1
Trong khodng trd nilng tuqng uA lu6i
phdn rftrg chay vd ngudn:
Ry,
(t
s t S T): Kh6a S tdt,
rl;
:u,,f'u?*V=E
dt
i, UI)
Vi
clQng co hic ndy
= I,e
hoat dQng nhu mdy ph6t:
Va=E-RuIu
Dign dp trung binh ddt l6n tl0ne cd (xem
(2.57
otEu
xurEr'tr6c oQ
DeNG
co MOr cutEu
65
Tn Q.57) vd (2.58) suy ra:
E
r_
- -(1-y)V
Ru
(2.5e)
'u
Luu y
tlfrng d chd
ld
ddng phdn rlng hic ndy c6 chi6u ngugc
lai
so vdi chi6u
clQ dQng co.
Girii cric phrrong trinh (2.55) vn (2.56) cho ph6p tinh drroc don s6ng
dtrng phdn ftng Liu. Bidu thrlc tinh Ai.. cing tudng tu nhrr (2.49) hodc
(1,60). Don s6ng ddng crrc clai xdy ra tai y 0,5.
=
.T
C6ng sudt trd v6 lrrd'i: Pu' = I [v.i,,dt
TJ
vT
(2.60)
C6ng thf'c (2.59) cho thA'y tai mdt t6'c dQ xdc dinh, ddng d6ng co
dUqc han chO'blng crlch gi:im y , Tuy nhi6n, lu6n c6 mQt gid tri gidi han
ln,r,, do ddc tinh cria linh kiQn hodc mach. Do d6, tdong rl'ng vdi ]a;n vA V
fho trrldc, sE c6 mQt gi:i tri td'i han c0a t6'c d6 md .khi vuot qu:i t6'c dQ
llly (trong trudng hop kich tir ctra d6ng co khdng thd gidm di), s6 kh6ng
lhd Cidu khidn bd chopper dd han chd drroc dbng phdn rlng (xem vi du 2.8)
thdng bQ Chopper - d.Qng cd DC hieh til ndi tidp
Mach tudng duong cria hQ thdng ndy clng gi6'ng nhrr mach trinh
lly tr6.r hinh 2.29a. Tuy nhi6n, cd.n luu f ld crrc tinh cu6n kich ttr phrii
llo chi6u so vdi khi hoat ilQng d chd d0 cl6ng co. DQng co hic ndy hoat
lQrrg nhu mQt mdy phrit DC tu kich til.
Vdi gia thidt su bao hda cria dic tinh trl h6a phu thuQc vdo giri tri
ftung binh cria ddng phdn rtng nhu d muc 2.7.2, tdc dQ dQng co tfnh bdi
rlg thfc:
(1- y)V + R,l,,
2- HQ
0)=-
Kn,
(2.6L)
Vdi mQt gi6 tri cho trudc cfia y, ddc tinh cd hoec ddc tinh tdc dd ctia
co DC kfch tU ndi tidp tinh theo cdc budc sau:
- Chon.fr,
- Tinh ra
K^
tt dic tinh til h6a
2.e HE rH0'Nc B0 cHoppER - oONc cd Dc l.Am vlEc noAr oOn
nnrEu cdc pnAru ru
Trong mgc ndy s6 khio s:it h€ thO'ng bQ chopper - dQng co DC
dQng dugc d ch6'dd h6m trii sinh, bao g6m hQ thdng hoat tldng d
I vi II, hQ thdng hoat dQng d phdn tu I ve IV, vd hO thdng hoat
duoc d cA bdn phdn trr cfia mdt phEng dic tfnh co.
Trong thgc td, mdt mach loc drtoc ddt girla ngudn DC vn b0
vd mQt vdng hdi ti6p Am dbng dd han chd dbng qua bQ chopper d
cho ph6p, c6 mit trong cdu hinh bQ chopper hoat dQng 6 nhi6u g6c
trr. Tuy nhi6n, dd don gidn cho vi6c gidi tich mach, mach loc vd vbng
tidp dbng s6 khdng x6t d dAy.
2.9.f He thdng bQ chopper - dQng cd DC hoqt dQng d phdn td I
HQ chopper - dQng co DC hoat dQng d phdn trr I vd II ddi h
chopper cung cdp dign rip duong nhung dbng diQn phrii c6 khd
chi6u. C6 hai so tld thrrdng ding nhrr trinh bdy dudi ddy.
So dd 7: BQ ehopper v6i eontact d.do ehidu
phdn tu
I ud.II udi c6ng td.c dd.o
,,tltt
KHTEN
rcic oQ oONe co Mer curEu
67
d6 h6 th6'ng ndy trinh bdy tr6n hinh 2.80a. c6 thd xem so d6
rrrly fir su kdt hop girla mach chopper d chd cl6 cl6ng co (H.2.2ga) vir
rrrr,rr,fr chopper d chd dQ ham trii sinh (H.2.2ga). S ld kh6a bdn dAn drroc
rlirlrr khidn dan trong khodng yT vd tdt trolg khozing (1
- y)?. c ln
r,lrtl,rrct di6u khidn bdng tay.
s<r
Khi
c
d6ng, mach c6 cdu hinh tuong tu nhu mach hi'h 2.80a vd
d che cl6 dong co. Mach tuo'Dg dtrong ctia h6 thong nhrr hinh
'J il()lr. Lfc nAy, di6n the diOm a duong hon di6u the diOm b.
116 tho'ng chuydn sang hoat d6ng o chd d6 ham trii sinh (g6c phdn
Irr ll)khi kh6a c hd ra, vd cuc tinh di6n rip ddt l6n phdn fng dtroc d6o
llrit\u bdng b6 contact d6o chi6u T-N, khien diejm b hic ndy drrong hon
rltdrn o. HQ thdng ldc ndy hoat d6ng o chd d6 ham trii sinh nhrr hinh
t !ltl, trd ndng lrtong v6 lrrdi. Mach tuong dLrong ctia.h6 th6'ng nhu hinh
Irrrrrl rl6ng
'/ il0c.
ohuy6'n tr} chd dQ cl6ng
lrlr, lrddc nhd sau:
co"
sarg chd d6 hdrn trii sinh thrrc hi6n theo
- Kh6a bdn dAn,S cluoc kich tdt vd khda C hd rnach. Do d6, dbng
rf l4rr phdn rlng s6 chriy qua D2, ngu6u v vd D1. Naug
luo-ng trtr trong
;rlrdrr ri'ng dong co drroc dua trri lai ngudn, vd do d6, dbng phdn fng s6
lltlrrt xu6'ng zero.
- sau mot khoring thdi gian tr6 thich hop dc d:irn bzio ddng phdn
tlrrg gizirn xudng ddn zero, b6 contact drio chidu T-N tric dOng cld tldo
r,lril'\u phdn r1'ng dQng co. Tidp d6, khda brin dAn s drroc kich vdi hQ s6'y
llrlt'h hop dd bdt ddu quri trinh trd n6ng ltrong vC lrrOi.
so dd kidu nhy drroc dirng r6ng rdi trong truydn d6ng cric xe di6n
ttgdrrr vd cdc xe diQn srl dung accu.
Ditng chopper l6p C (bQ dao d.bng)
Trong mQt s6' rlng dung,
didu khidn d6'g co *!iervo, mriy c6ng
'hu
rrg, rldi h6i srr chuydn mach 6m vd nhanh tir chd d6 ct6ng cd sang chd d6
ft6rrr vd ngugc lai. Khi d6, bo chopper ld'p c c6 so d6 ngrry6n ry nhrr hinh
tf ftlrr duoc sfi dung. Khoa brin ddn 51 vd diode D2tao thdnh mQt mach
frltrrlrrrer, s2 vd Dltao thdnh m6t mach chopper khric. sr vd s2 dLroc didu
llridrr d6ng cdt nguoc pha nhau, trong d6 s' duoc kich dAn trong khoring
0 .- t < yT, cbn 52 dtroc |rfch dAn troug khoeing yT < t < T.
So dd 2:
Dz
+
vd
a)
1,4
t,0
o,&
0,&
0,o
o,@
o,o
t,a
Vctz
t,@
0,0
o.o
o.€
0,&
0.@
vd
l.2O
0.s -L.
8:$ F'
0.20 r'
o.@ F.
40o L
9.@
2,@
1,@
o,@
-1,@
4.O
<,@
l,o
2,@
t.@
q,@
-1,@
-2po
4,@
Dr Sl DzSz
b)
Hinh 2.37: BQ chopper l6p C + dQng co DC
a) So iI6 nguyan t!; b) DcnE s6ng ' khodng d6'n cdc linh, kiQn
Dang s6ng cria tin hiQu di6u khidn vd dbng dp ng6 ra duoc tri'rl
tr6n hinh 2.31b. Mot sd dac tlidm sau cdn lur y tld c6 thd hidu tlrrgc
tlQng cria m4ch:
- Trong mach rrdy khilng xd,y ra hiQn tuqng ddng gidn d'ogn,
k] tdn sdho4t dQng ndo.
- Ddng in vd i, c6 thd ddn theo ci hai chidu. Do d6, trong
0 < t < fI, dQng co drtoc ndi vdi ngudn qua 51 ho{c D1' Nhrr vQy'
ttu U KHIEN
rcjc oe DING co Mor cutEu
69
l,lrrrrr ri'ng'd6ng co duo-c ugdu rnach qua D2 hoic Sr. Tuo-ng ri'ng, rli6u dp
rl<lng co ld 0 vd Loc d6 bi€il thi6n ddng ,,, ld am. Dieu ndy gi:ii thich
rlrrrrli sting duoc trinh bdy tr6n hinh 2.31b.
Ir.rr
'l'rr dang song dien dp dat l6n dorrg co rr6n hirrh
2.3lb, tinh duoc
lip
trung
binh
tr6n
d6ng
co:
'lr,,,rr
Va=N
'l'tr ddy, suy ra: Iu
tA/-
F
= Jl-----D
totl
(2.62)
oong thf'c (2.62) cho thdy dong co ldm vi€c ci' ch€ dd d6ng co' (1,/ > 0)
lrlrr y > (E/v), vd o che dQ ham tdi sinh khi v < (Erv). Didm rdm viec
lrlrrrrrg teii xdy ra khi .t = (E lV).
Vdi giri tri cho trudc crla y, d6 don s6ng ddng tinh theo c6ng thd'c
tii l1)) hodc (2.50). C6ng thf'c ndy cho thdy ring d6 don s6ng ddng kh6ng
|lrrr t,hudc vdo giri tri cria tO'c d6 d6ng co. vo'i m6t gid tri y cho trrldc, str
tlrrrv ddi tdc dQ sd dA' den str thay ddi v6 dbng tru'g binh nhrrng d6 clon
,',rrry1 rlbng girl nguy6n.
Irc thong bq chopper - d6ng cd DC hoat d6ng o phdn trr r vi fv
136 chopper ldp D c6 cau
lrtnh nhu rnach hinh 2.32 duoc
l?.1).?
,lrrrrg (b0 d6o r{p).
C6 nhi6u crich didu khidn
v
hinh 2.32. Sau ddy
l,ri t'hopper
sdt phuong phdp diiiu
Itlrialn thrldng sti dung nhdt.
tJrr.y luAt didu khidn czic kh6a
lrrin dAn 51 vd. 52 theo phuong
,,,, khdo
lrlrrip ndy nhr,I sau:
- 51 vd 52 duoc kich dAn
li,tr:h pha mOt khoing thdi
girru ?.
- Chu k) d6ng tdt
Itlr/ra bdn dAn
m6i
Hinh 2.32: 86 cltopper ldp
D + d6ng co DC
ld 2?.
- M6i kh6a bdn dAn, Sy vd 52, duoc kich dAn trong kho|ng 2^lT.
l- 0,60t-0,10 l- - 0,20r-1,00
0.80 l-
vdk"
r.m0.80
F--
0.40
0.20
F-l--
0.60r--
:-c-
t2o,oo
L_
FFF-
E0.00
60,00
10,00
20,00
---
4.00 ;3.50 F -
3,00 l-
-
i;;EEZ
is
4,00
3,00 E
f:
?#r=
L
0,00
992,00
995.00
994.00
996 oo
Thdi gian (ms)
a)
sls2
slD2 s1s2 s2D1
1,20
1.00
0.80
8rl8
o,20
0.00
1,20
r.00
0.80
8:?8
0,20
0,00
F=
F:.
E:i
0,00
-20,00
-40,00
:8888
100,00
120,00
01
01
00
00
09
50
00
50
00
50
09 00
o0 00
80,00 r80.00 r -'
40.00 t 20.00 l- 0,00 | .20.00
992.00
-
99'l
oo
D2Sr D1D2 S2Dl DrD2
990'oo
Thdi gian (ms)
KHTEN
r6c oQ oONo co
MOr cutEu
Do dd, tr6n hinh 2.33, Sr sE drrqc kfch d6n tqi I = 0 vd kich tdt tai
rgyl, 52 duockich d6n t4it= ?vAkfchtdtt4i t =T +z^(I. D6 thi
dp vA ddng diQn ng6 ra bQ chopper trinh bAy tr6n hinh 2.83, ddng
khoeng
dan diQn cria cdc linh kiQn trong m4ch ciing dudc trinh bey
Scl
lung
rlng.
TU dd
f
thi tr€n, nh{n thdy:
; . Vdi 0,5 < T < 7, 51 ud 52 kh6ng thd tdt d6ng thdi . Do d6, diQn rip
lfO ra bQ chopper ld +V hodc 0, vd diQn dp trung binh ng6 ra V6 > 0. HC
lhdng hic ndy hoat dQng d g6c phdn trr l.
, - Uli 0 < y 1 0,5, 51 uti 52 khing thd ddn d6ng thdi. Do d6, rliQn dp
l;0 ra bQ chopper le -yhod.c 0, vA diQn dp trung binh ng6 raVa < 0. HC
Stdng hic nAy hoat dQng d g6c phdn trr IV.
DiQn rip trung binh ng6 ra cia bQ chopper (diQn dp
-2t
I
v6- | lvat =2v(y-o,b)
T
,T
vo=i )GDat=2v(,t-o,b)
Uot0,5<y<1:
:
Vdi0<y<0,5:
dIt l€n tlQng
co):
(2.63)
2^(r
Nhu vfy, bidu thrlc (2.63) c6 thd dnng dd tinh diQn rip trung binh
ra
cria bQ chopper ldp D trong ddi bidn thidn cria y til 0 -+ 1.
Bl0
, Ddng phdn fng trung binh:
7,,=
"
vo-E
R,
=
zvQ-,,il-E
R,r
(2.64)
19.8 H6 thdng bQ chopper - dQng cd DC hoqt dQng E bdn phdn trr
, He th6'ng sfi dung bQ chopper tdp E nhrr trinh bdy d hinh 2.84.
l,
l-
t9
*l
s1
D3n
+
s4
*l
vd
-
s"
a
CHUdNG
BQ chopper ndy c6
CAah
thd duoc didu khidn theo cdc cdch
sau.
I
- Hoat tlQng 0 phdn trr I vd II: 52 drroc kich d6n li6n tgc, ,S1 vA
tlugc tli6u khidn d6ng tdt ngugc pha nhau. Khi il6, ta duoc bQ chopp,
/
kidu tlAo dbng nhu hinh 2.31a.
- Hoat dQng d phdn tu III vd IV: 53 drroc kich d6n li6n tuc, 51 vA /
dugc didu khidn d6ng tdt ngugc pha nhau. Khi tl6, ta drtoc bQ chopg
kidu d6o dbng nhung cuc tinh diQn rip ra nguoc lai.
I
Khi d6o chidu quay dQng co, vi du chuydn til g6c phAn trr I
hoat dQng d g6c phdn tu III, qud trinh tli6u khidn cdc kh6a brin d6n
hinh nhrt sau:
- GiAm y tldn girl tri crr. c tidu, dbng tlQng co s6 dio chidu vi dat
tri cuc dai (2.59). Dbng niy s6 duoc han chd bdi vbng hdi tidp dbng
trong mach didu khidn. DQng co hoat dQng d chd clQ hdm teii sinh
giim t6'c.'
- Khi t6'c rl0 gi6m ddn 0, 52 drtoc kich tdt, 53 duoc kich dAn.
kh6a Sr vd Sa drroc kich cl6ng tdt vdi hO sd di6u chinh T tudng rlng vdi
tlO cdn thidt.
Do cdc kh6a brin d6n aldi h6i c6 thdi gian tdt nhdt dinh, tt4c bi
khi srl dung SCR, giri tri crJc tidu cfia di€n rip ra ctia bQ chopper, vd
rl'ng ld gi6 tri cuc tidu cria t6'c tlQ dQng cd, s6 bi gidi han. Ngodi
trdnh trr)ng d6n xdy ra gifra 51 vd Sa ho4c 52 vd 53, mQt kho6ng
gian chdt duoc dua vdo khi chuydn m4ch xung kich cho c6c cdp
tr6n. Di6u ndy sd han chd diQn rlp cttc dai d ng6 ra bQ chopper, vd
rlng lA t6'c d0 tdi cla cria tlQng co c[ng bi han ch6'.
Cdch 2
Kh6a bdn d6n 51, 52 ctng diode D1, Dz }aqp thdnh mach
kidu d6o :ip nhrr hinh 2.32. Mach chopper ndy hoat tlQng d g6c phAn
vd IV. ViQc kich cdc kh6a Sr, Sz thuc hiQn nhrr trinh biy trong 2.9.
Tuong tU, Sg, Sr vd diode Ds, Dt t4o thdnh mach chopper hoat
6 g6c phdn tu II va III.
Cdc mach chopper tr6n kh6ng ho4t tlQng ddng thdi, nghia ld
chopper g6m S1, 52 dang hoat tlQng
thi b0 chopper gdm 53, Sa s6
ultr xnEN r6c oq oQNo co M)r
()huydn mach
tt
g6c phAn trr
73
cutEu
I
sang
III
duoc thrrc hiQn nhu sau:
- Tdt cd,c kh6a Sr vd Sz. Dirng tlQng co ltic ndy s6 ch6y qua D1,
rrgrrrlrr vvd diode D2,vd. nhanh ch6ng gi6m xudng 0. srlc diQn dong dong
tinh + d b6n tr:ii.
- Kich 53 vd Sa vdi y trong khoing 0 -+ 0,5, thudng 6 gi6 tri gdn 0,5'
llnrrg dQng cd sO chay theo chidu ngugc lai vd dat giri tri crJc dai theo
r,0rrg thrirc Q.6t). Ddng ndy s6 duoc han chd bdi vbng hOi tidp ddng tliQn
Irilrrg mach didu khidn. DOng cd hoat clQng d g6c phdn tu II va giAm t6'c.
- Khi t6'c tlQ dat gdn zero, y s6 drroc hi€u chinh cldn giri tri cdn thidt
I r rrng khoing 0,5 + 1, dQng cd sE tdng tdc theo chidu nguoc lai ddn didm
lArrr viQc dn clinh trong g6c phdn tu III.'
rrr,
l.r0n hinh 2.34 sE c6 crlc
Cdah 3
kich cric khd,a b:in dfin trinh bdy tr6n hinh 2.35a,b. ViQc kich
r,rrc kh6a b:ln dan drga tr6n nguyen tac kich gidng nhrr phdn trinh bdy
llong cdch 2 vdi mQt s6'thay ddi nhtr sau:
- Cdc mach chopper hop thdnh bdi (Sr, Sz) vd (Ss, S+) s6 duoc di6u
hlricn ddng thdi (thay vi didu khidn ri6ng rE nhu d cdch 2)'
- Kh6a (Sr vir Sn), (Sz vA St hgp thbnh c6c cf,p bd phg (complementa4r
pha
lrrlr), nghla lDr cric kh6a trong tirng cqp ndy s6 drroc kich d6n ngrroc
So dd
rrlrnu.
Chu kj tl6ng ng6t cria m6i kh6a ld 2?. Trong khoing thdi gian d6,
lroat dQng cfra bO chopper c6 thd chia thhnh bdn khodng, kf hiQu I, II,
lll vi IV nhrr trinh biy tr6n hinh 2.35.
Gia thiot rlQng co hoat dQng d pldn tu I (chd c10 dong co), dang s6ng
rlr)ng vd dp tr6n tlQng co nhrr hinh 2.35a. Dang s6ng ndy c6 thd gi6i
l,hich nhu sau:
- Trong khoing I, 51 vd Sz ddn. DiQn rip cung cdp cho clQng cd, do
116, sE lA duong vd ddng phAn rlng t[ng.
- Trong khodng II, 52 tdt, Sr vd 53 tlrrgc kich d6n. Vi ddng qua tlQng
co dang ch6y theo chidu duong n6n s6 kh6p m4ch qua D1 vd s1. Lric ndy
rlp tr6n clQng co bhng 0 vDr dbng dQng co gidm. Kh6a Sr d trang thdi t6t
tlo bi phAn c\tc ngugc bdi tliQn 6p sut qua D1 (tlang ddn).
- Trong khoang III, Sz drroc kich dan trd lai. Do il6, dien rip tr6n
CHUONG
- Trong khoAng IV, S, t6t, Sz vd Sa nh{n tin hi6u kich. Dbng d6ng
co lric nay, vin duy tri chi6u dtrong, s6 chriy qua s2 vir D2. Kh6a sa
trang th{i t6t do bi phrin cuc ngudc b6i diQn dp roi tt6n D2 (dang d6n).
Lm f ld diQn dp ra cria bQ chopper gi6'ng nhrr trinh bAy tr6n hi
2.33, do d6, cdc c6ng thrl'c (2.69) vd (2.64) duoc dp dung cho mach ndy.
|,20
1,00
0.80
0,60
0,40
0,20
0,00
1,20
't,00
0,80
0,60
0.40
0,20
0.00
1.20
1.00
o,20
0.00
1,20
t,00
0,80
0,60
0,40
0,20
0.00
992,00
€.+€
sts2 srDr srsz
szDe
vd
120,00
100,00
80,00
60,00
40,00
20.00
00,00
-20,00
133
_:F:: l::: l::: l:::
:::E_:l:::l_::l:::
:
|
l:il1
;:SSJ
t,oo
J
il[
tfit
992
,00
994,00
996,00
Thdi gian (ms)
Hinh 2.35a
998.00
xnErv r6c oQ olxa co M1r cnEu
ptf tt
lo
n
I
ilj
0 9t)
)
v
0
n
996,00
Thdi gian (ms)
t1t(xl
tI
txl
lur lnl
tut txi
aril rl)
,il0 rl,
a
a
rh ril)
In
[
Inl'
t-
ntx)il txl
n rx)
til In)
h,t)t)
,0 (x)
092,00
994,00
996,00
998,00
1000,00
Thdigian (ms)
D3D4 s3D3 D3D4 s4D4
tdi sinh (phd.n tu II) 0,5 s y 3 1 ud, va < E
Chd d0 ldm vi6c tlQng co (phdn t'.I I) xay ra khi Iu > O.Ch6'dO lam
viQc c6 thd chuydn sang hdm trii sinh (phAn tu II) blng c:lch girim y holc
f tlrrg E sao cho Va < E hoic /, < O (2.64). Dang s6ng ddng vd rip trdn
rfQrrg co lric ndy nhu trinh biy tr6n hinh 2.35b. Trong m6t chu kj 2?., e6
llr{i chia hoat dQng cfia bQ chopper hic nAy thdnh bdn khoAng nhu trinh
lrAy trdn hinh 2.35b. Hoat dQng cria mach chopper trong m6i khodng c6
Htnh. 2.35b: chd dQ hd.m
- Trong kho6ng I, 51 vd 53 nhAn tin hiQu kich d6n. Srl'c diQn
duong cria dQng co ltic ndy ldm cho dbng phdn rlng iu chriy qua D3 vd
Trong khoring thdi gian nAy, I iul t6ng,ldm tdng ndng luong tfch
trong diQn khdng mach phdn rtng. S1 tdt do bi phdn cuc ngudc b6i
6p roi tr6n D3.
- Trong khodng II, S3 ttt. Ddng phdn rtlrg hic ndy chay qua
ngudn V vd diode Da, vir ndng lrrong dtroc trd l4i ngudn. Mac dn 51 vd
nhan tin hiQu kich trong khodng thdi gian nay,. ed.c kh6a tr6n v6n t6t
bi phdn cuc ngudc bdi c:ic diode D3 vir Da. DiQn rip cung cdp cho dQng
lric ndy ld Vvd liul giilm.
- Trong khodng IV, S4 drroc kich dAn. Ddng phdn ring hic nhy
chriy qua sr va D* l{h6a s2 cfing nh{n drroc tin hi6u rlidu khidn nhr
khdng dan tlrroc do bi phdn cu.c ngudc bdi di6n rip sut qua Da. Bi6n d
ddng phdn wrg lrlc ndy tdng l6n.
- Trong kho6ng IV, S4 tdt, ddng phdn ri:rg chAy qua D3, ngudn V
Da, vd, ntrng hlong duoc tr6 vd luOi.
ChC'd0 ldm viQc d6ng co vd hdm t6i sinh theo chidu nguoc lai (
tu III va I9 nh€in drroc vdi 0 < 1 < 0,b, khi d6 Va < 0. Chd d6.ldm vi6c
co (phdn tu III) nh{n tlrroc khi he sd y drroc chinh sao cho lvdl >
Tuong tu, chd dQ hem trti sinh (phdn tu IV)
chinh y sao cho lDl > lvl.
Iic ndy
lDl
nhQn duoc khi did
Phrrong phrip cli6u khidn ndy c6 mach didu khidn don giAn hon
1
vd 2 dA trinh bdy d tr6n.
sil
rAp cHUdNG
2
Vi drr 2.1. Ddng cd DC kich tU dQc lfp c6 th6ng sd:
Pd^= 29kW; Vd^ = 44OY; Ia- = 76A]' na^ = IOOOv/p; Ru = 0,B8Cl
a) Chon mriy ph6t dd c6 thd kdt hgp vdi dQng co tr6n thAnh hC F-D.
b) Gia thict kich tir dQng co git kh6ng ddi vd bhng rlinh mrlc trong
sudt dai didu chlnh tdc dQ, x6y dqng cric ddc tinh n ='f(I) cria hQ F-D
tron tuong rlng vdi cdc didm ldm viQc c6 ddng t6i = 16- vd tdc d0 ldn lrrot
le 750, 500 vd 250v/p.
c) Xdc dinh ddi didu chinh tdc d0 cria hQ tr6n khi kfch til dQng co li
dinh mfc vd ddng ctrc d4i cho ph6p cfia dQng co lit I* - 2Ia^.
77
otEu xutEv r6c oQ o2xa co M1r cnEu
Hinh 2.36
(|tci
a) Cdng sudt vdo cria dQng co:
= 440x76 = 33,4 kW
Mdy phrlt ph6i chon sao cho cdng sudt tlinh mrlc mriy ph6t
I',t,nF ) c6ng sudt dinh mrtc dQtg.co P6^B'
Tra bAng catalog mdy ph6t chon duoc mdy c6 th6ng sd sau:
C)
Pd* = 41 kW; Vd* = 440 Y; Ia^ = 89A; rldm = L47o v/p; 'R7 = 0'336
Pd*D = Va^.Ia^
b) Tdng ctiQn trd Phdn rlng cfia hQ:
Rz= Ruo + Rue = 0,38 + 0'336 = 0'716
Hbng sd Ko cria dQng co:
va^ -Ru'Ia*
Kea*
-
@d^
-
440- pr3-8-x76
t04,72
Cl
= 8,926V.s/rad
d4c
Xdy d.4tng dqc tinh tdc iIQ qua didm (nt = 750u lp' I' = 76A): Vi
nfia
tlidm
mQt
th6m
tim
rtnh tdc dQ cria hO la dudng th&ng n6n ta cAn
tinh ndy.
tr6n d{c tinh. d ddy, ta tim didm kh6ng railg trldng crla d{c
srlc rliQn dQng cria mdy ph6t cdn thidt tld tlEng cd lim viec vdi
I,t = 76A l4i n = 750v/p (tor = 78,54rad/s):
Ert = K@a^. @1 * 16^R2= 3,926 x 78,54+ 76 x 0'716 = 362'5 V
Tdc
t10
kh6ng tai l)t trldng cria tlQng co khi d6:
En - 364
..
(&t=U;:=-s,s26
= 92.33 rad/s
Ttrorg
tg d{c tinh tdc dQ qua didm (zz = 500v/p, I,t =
- 76A) c6 cac didm kh6ng t6i lj trrdng tudng ung ldn
n"z = 632 v/p; noe = 882 vlp
(ns = 25ov/p,Iu
tfnh tdc d0 niy v6 tr6n hinh 2.86.
c) Ttr didu ki6n dbng quri tAi cho ph6p cria dQng cd: .I-o
= 216^,
tlQ thdp nhdt crja hQ o\";" drroc xic dinh til ddc tinh
mi 6 tl6 ddng
dat duoc khi n = 0 (xem hinh 2.86).
Srl'c di6n tlgng mdy phdt cdn thiet dd ddc tinh tdc
dQ qua
(n = o, It = 2Ia):
EF*in = R2x 2Ia^,= 0,716 x 2 x T6 10g,g! V
=
TrOn ddc tfnh nAy, tai Iu = Ia^, l6c d9 d6ng co ld:
EF^in-R:-'Id^ 108,83-0 71tr'vnA
o)6;. -=
ri{ntn
= 13'86 rad/s
3,926
-Bu^
C:{c ddc
-
= L32 v/p
Ddi didu chinh (vdng hd) cria hC F-D da thidt kd:
zmin
D=ft^^* -1000 -nE4
=
zmin
"o'
-
1000
750
500
250
132
76
Hinh 2.37: Dec tinh tdc
lu(A)
dQ he
F-D cila ui d.u 2.1
KHTEN
rdc oQ o2Na ca
MQr
cnAu
Yl arl 2.2. DQng co DC kich tir
dQc lap c6 th6ng s6': R, = O,25dl,
cdp
tir mQt cdu chinh lur mEt pha didu
duoc
cung
0,896
V.s/rad,
=
n bdn phdn. Dien dp AC cung cdp cho cdu chinh hnr c6 tri hiQu dung
, tdn sd 6OHz. Gie thidt diQn c6m trong mach dfi ldn tld ddng Iu c6
coi lA li6n tgc vd ph8ng. Ngoii ra kich til dtroc gifr khdng ddi vd
ng dinh mrlc. 86 qua ma sdt vi tdn hao kh6ng t6i. DQng co ldm viQc
tAi c6 M = 45 Nm t4i n = 1000v/P. Tinh:
ilrl
l,
l"
1- G6c
kich a cdn thidt cria
bQ
chinh lur.
2- He sd c6ng sudt ng6 vdo cria b0 chinh lrru
khi
tl6.
0lll
1- Ddng phdn rrng
,, =#=o**
t4i didm ldm vi€c:
=50,23 A
Di€n 6p cdn cung cdp cho d6ng co:
va = K.o .ro+.Q ./,2 = 0,896x
G6c
10091< 2n
60
* 0,25x50,23 =106,39 Y
kich a cdn thidt ctia b0 chinh lur:
,"
2- Ndu dbng
(1 + cos(cr) )
=#x
tdi ld li6n tgc vA phEng, cdng sudt ra ctia b0 ehinh lrru:
Po =Va '/,2 = 106,38x50,23
86 qua tdn hao tr6n
oCp tU ngudn
= u = 82,2
bQ
=5343,5 W
chlnh lttu, Po c0ng ld cOng sudt thuc P; cung
xoay chidu.
Goi i" ld ddng ng6 vdo bQ chlnh hnr nhrr hinh b6n, i" s6 c6 dang nhu
htnh (a) do dbng f, ld li6n tuc vA phing theo gi6 thidt dd bdi. Gid tri
t
hi0u dr,rng cria
i":
?[--A
Ishd=
n
,ijiiji@
HC sd c6ng sudt ng6 vdo bQ chinh
=ifr=
Hscs
lrrr"r:
,offi=0.6e4
Vi dq 2.3. DQng co DC kfch tt
dQc lap c6 th6ng sd: R,, = 0
K@a^= 3,164 v.s/rad, duoc cung cdp tt mot cdu chinh lrru mQt pha
khidn todn phdn. Di6n rip AC cung cdp cho cdu chiuh luu c6 tri h
dung 440V, tAn sd 6OHz. Gid thidt diQD cdrn trong rnach dri ldn dd
Iu c6 thd coi ld li6n tgc vd phi'g. Ngodi ra, kich tir duoc gitr kh6ng
vd blng dinh mfc trong qud trinh di6u hhien. 86 rlua ma sd.t vd tdn
kh6ng tdi.
1- Ndu ddng tdi
a) M6men
Ir=
tr6n
45A vd g6c kich u = 60". tiulr:
truc dQng co ;
b) Tdc d0 dOng co;
c) HQ sd c6ng sudt ngd vdo bd chinh luu.
2-
Gi thidt dQng cd dang hoat dQng nhd d cau 1 thi srl'c dien d0
cria dQng cd dudc d6o chidu (vi du drio chi6u dion rip phan rlng
didm), dQng co d chd d0 ham tzii sinh, tinh:
bing ti
a) G6c kich a'dd ddng qua dQng co vAn ld 4;tA 6 thdi didm
chi6u srlc cliQn dQng;
b) COng sudt trri vC lrrOi khi tlij.
ciai
v" = 44ov
I
M = K' o "I'1 = 3'164 x 45 = 142'4 Nm
DiQn dp trung binh ng6 ra cia bQ chinh hnr:
1- M6men dQng co sinh ra:
vo
-
2Ji ^v
Tn
x oos cr
khi d6:
E =Va - Ru'Iu
x
-' 2tD' 4!0
co-*
60o
-
198'
Sdc di€n dQng dQng co
= 198'07
-0'25x 45 - 186'8
0?
y
y
Tdc tlQ dQng co:
,=*=
KA
1t?? =59,olrad'ts ho{c 564\rtP
3,164
COng sudt thr/c ng6utro
b6 bidn ddi:
4 =Va 'Iu =L98,07 x45 = 8g7g,2 W
Goi i. la ddng n86 vao b0 chinh lur nhrr hinh b6n, l" s6 c6 dsps nhrr
hlnh (a) do dbng .I, ld 116o tlrc va ph6ng theo gi6 trrigi aa aai--bia tn
hlfu dung cfia i":
I_
'cild
HQ sd c6ng
suil
ngo
vdo b6 chlnh
flBcs
=
=In=45 A
=
-
lrr':
P.
8913,2
V".I"na
440x45
= 0,45
2- Ndu srl'c diQn dOq cria dQng co d6o dau vd ddng qua dQng
cd vdn
lhn. chiiiu nhu c[, tlong co hoat dQng d ch6' d0 hem tdi sinh. -Kbj do,
lllD ap trung binh ngd ra cria ciu chinh lur ld:
V
Va
= E + Ru . Iu = (-tgo,gy) +0,25x45 = -17 5,Ej7
G6c
kich cAn thi€t
cria
b0 chinh lrr':
cosq=-ICIfi- + G=116,8g"
2,l2xV
C0ng sudt dQng co1,6 vd lrrdi:
P,,
=Va' I u = 175,57 x 45 = 7gOO,7 W
Ittu'v: Khi hfrm t{i sinh, tdc dO va srlc diQn dong cria dQng gd sE
r ddn theo.thdi giax
N6'u ddng phAn fng cAn duy tri I mrlc ru = 45A
qud
trinh hdm, 96, kich a cdn phai giam tudng rrng. Dd thuc /riQn
J
nAy, ilQng co cdn duoc didu khidn kidu vdng kin vdi hdi tidp
/bos
duy tri dbng phdn fog la hhng sdva thay ddi li6n tuc g6c kich q,
lu l.l. DQng co DC ki.h tt ndi tidp c6 Pu^ = 1b kw, V6^ = 2f,ov,
r 900v/p, drroc cdp {iqn lai mQt cdu chlnh lrru mot pha tlidu yyaidn
1
phAn' DiQn dp AC c\ug
cdp cho cdu chinh lrru c6
tri hiQu dqngzOov,
60Hz' Tdng diQx
'6rfng_ c6 thd xem ld tr& phdn rlng vi cuon kfch til la 0,1b0, lru"e
licn tuc vd prr&rrg. Gie thidt mach tu dQng e 4 liL
tlnh vd tu th6ng donc
thfc: K@
1- M6men dQng co, dbng phdn rlng vd hQ sd c6ng sudt b0 chtnh
86 qua ma sdt vA tdn hao khOng tdi.
2- Tinh c6e gi6 trf tron ndu bQ chinh lrrrr bay gid la cdu chinh
toin
mQt pha didu khidn
Phdn.
Giai
1- Tdc tlQ dOng cd: o =
T =ry
= 94,2
ra.d' I s
DiQn :ip trung binh ng6 ra bQ chinh lmr:
!-n,,
vo
Ta c6:
=#G+
6-
coso)
(R,
,=vo
KA
=9#t1+
cos30')
=2!8,48 V
+ Re,)'Iu _Vd -(Ru + Re)' Iu
KKhtlu
Suy ra ddng phdn rlng:
Iu=
vd
(KKH). or+(.Ru +
Rnt)
2t8,48
=73,41 A
0,03x94,2+0,15
M6men dQng co: M = K'Kor'I"u = 0,03x?3,4L2 =L6]^,7 Nm
86 qua tdn hao tr6n b0 bidn tldi, c6ng sudt thuc drra vdo bo bidn tldi
4 = Va' It = 2L8,48x73'4L = L6062'I W
C6ng sudt bidu kidn n86 vdo b6. bidn tldi:
VI --
260 xla, +r
t
/180-
= L7 423,6 VA
HO sd cdng sudt bQ chinh hnr:
p- 16062,1
f/scs
=fr=
1742g,6
=0.g2
2- Ndu bQ chinh luu b6y gid ld cdu chinh ltnr mQt pha di6u
todn phdn, cdc c6ng thrl'c tinh dbng .In vd m6men M clr;.g nhrt tr6n
vdi:
zJ-zv ,
,?
Vo =
-^., =- 2Jdx26o
,
T(cosc) ff(cos3O')
TU d6 tinh,drroi:: .[s = 68,05
A,
= 202,8 V
M = 138,92 Nm'
86 qua tdn hao tr€n b0 chinh htu, c6ng sudt thrr. c drra vdo
b0
KHTEN
r6c oQ
D2NG
co MOr cutEu
C0ng sudt bidu kidn ng6 vdo bQ bidn ddi:
VI =26Ox68,05 = L7693UA
H9 sd cdng sudt bQ chinh hnr:
Hscs
=I=ry=0,28
w 17693
Luu !: Vdi ctng g6c kich o, he sd cOng sudt cria chlnh lnr didu
lhtJn bdn phdn cao hon chinh lrru tli6u khidn todn phdn.
Yl du 2.6. DQng co DC kich tr} dOc l,4p 12b HP (lHp = T46W),600 V,
lf00v/p duoc didu khidn tdc dO blng mQt cdu chlnh lrru ba pha didu khidn
Itln phdn. Cdu chtnh lrru drroc cung cdp tt ngudn xoay chidu ba pha 480 V
($ aayl, 60 Hz. Ddng phdn rhg djnh mri'c cria dQng co le rcb A. Cd; th6ng
dkhac c&a dQng colh: 8, =0,O874dl,Ly= 6,5mH, K@ = 0,33 V/v/ph. 86
lur tdn hao tr6n chinh lrru vd ngudn. Ddng.t, coi ld li6n tuc vd phEng.
1- Tinh t6'c d0 kh6ng trii vdi g6c kfch a lAn ludt le 0o vA 80". Gi6
lhldt dbng kh6ng tAi blng tOVo ddng dinh mrlc.
, 2- Tinh g6c kich cr ttd dQng co hoat dQng d tfc tlQ 1800 v/p vdi
lt. Iua^. Tinh h€ sd cdng sudt ngu6n khi tl6.
3- Tfnh d0 dn dinh tdc clQ vdi g6c kich vd tlidm ldm viOc d cdu 2
1- Chd dQ khdng
tii:
It=
DiQn dp pha cria ngudn AC: V
DiQn dp trung binh ng6 ra cd,u
vo
Vdia=0o:
'
TO'c
=}JaIt
-
tOVo
, Id^ = 16,5 A
480
=277 Y
v3
chlnh lrru td:
'v."o"o
= 648x cosa
[v]
V6=648Y
Va=E+Ru-Iu
-
Va- RxIa= 648 -16,5x.0,0874 = 646,6 V
d0 kh6ng tAi vdi c = 0:
E
n"=#=
646'6
Vdio=30o: Va=56t,2Y
=1959 ulph
Tdc d0 kh6ng
2-
tli vdi c = 30o:
,o= E 559.8 =1696 ulph
KO=ffii
tai dinh
I,t= Id* = 165 A
Dign dp cdn cung cdp cho tlQng co tld tlQng co lim vi6c vdi
ChL6
d0
n = 1800 v/ph:
Vj = E + RnIu
G6c
tri
16^
KQn+ RrIu =0,33x1800+0,0874x165 = 608,4 V
-
kich s cdn thidt:
.
Giri
=
mrfc:
co..p =
'
]?.
648=
u99in
648
=0,94+ a = 20,1o
hiQu dung cfia dbng ngudn:
-
I Aha
tz-
={Ett"
=
t,
A
{=tt6S =134,64
C6ng sudt hiQu dung ng6 vAo bQ chlnh lrru:
VI =3,277x134,64 = 111885,8 VA
86 qua tdn hao tr6n bQ chlnh lrru, c6ng sudt thqrc dua vdo bQ
Irnr blng c6ng sudt dua ra dQng co: Pt=Va.Iu= 608,4x165 = 100386 W
HQ sd c6ng sudt bQ chlnh lw:
100386
Hscs
-4vI - 111885.8 -0.9
3- D0 dn dinh tdc tlQ:
d
chddQ kh6ng tai(Iu= !\Vo l,ta^), stc diOn dOng dQng co s6 lA
kich cr = 20,7? nhu 6 cAu 2):
E =Va -(16,5x0,0874) = 606,96 Y
Tdc t10 khdng
tdi cfia
tlQng co
no
=6E
khi
(
d6:
606€
=T-BB =1839.3 ulph
D0 dn dinh tdc d0:
Ltto/o =
1839,3 -1800
x100 = 2,18%
1839,3
Vl drr 2.6. MQt dQng co DC kich tU dQc lflp
E = 2A0Y, nu -- 3.Ct,
cdp ngudn til mQt cAu chlnh lmr mQt pha tlidu khidn toAn phdn. Ngudn
xoay'chidu cung cdp cho cdu chlnh lnr c6 tliQn dp 220V, tdn sd SOHz
diQn c6m ngudn lmH. GiA thidt tliQn khdng mach phdn rturg dfi ldn
c6
KHTEN
r6c oQ o2uo co M)r curEu
l. Vdi cAu chlnh hnr mgt pha didu khidn toAn phdn, sgt dp trung binh
ohuydn mach lA:
LV,-
vay:
='X'
n
'
I't
,,={ft=#=81,56A
tnu
(V6 = Q,gy" 'cosc =
-;
-99V ; Ea=
3C);
R"^ = 2X"/n = O,2e)
Sqt dp trung binh do chuydn mach:
LV"^
1
=ff
n =0,2x31,56 = G,gl2v
G6c chuydn m4ch p:
t
2L
av"^ =-v'o-
=
6,812
=
'
-?
;-.o* o
-
cos (cr +
*[.or(r20")
r
2t
p)]
_ cos(120. +
p)]
|r = 4'3160
Vl dq 2.7. 86 chinh lrru tia ba pha drtgc cung cdp bdi ngudn xoay chidu ba
pha c6 cli6n rip pha 150V, tdn sd lcOHz. BQ chinh luu ndy cdp ngudn cho
mQt dQng co DC kich tr} tlQc tQp c6 Ru = 2,5{t hoat dQng d chd dQ hAm tdi
rfnh vdi E = -250V. Gie thidt dign khdng phAn rlng dfi ldn dd ddng /, c6
thd coi ld li6n tuc vd. ph8ng. Ndu diQn cdm tr6n m6i pha cria ngudn xoay
chidu ld 3mH, tinh g6c kfch cAn thidt dd ddng phdn rlng hic ndy ld
04,9A. G6c chuydn mach khi tl6 ld bao nhi6u?
otdi
Vdi b0 chinh lur tia ba pha, sut dp trung binh do chuydn m4ch:
Ly^=ff u
Dd duy tri dbng Iu= 64,9A, diQn dp trung binh ng6 ra cfia bQ chinh
luu cdn c6 gi6 tri ld:
vao = E *
G6c
vr-
4-t"( nu* +2n)I = -250 + 64,9 x (z,s +0, 45) = -58,545 v
kich c cdn thidt:
^t;
.V" .coso
cosc
-58'545
Sr;t dp trung binh do chuydn mach:
Lv"^ =J/'o- * ;"o" o
29,2! =
#
-
"f
cos(109,5'+[) = 0,3U9
+
cos
(c + P)]
cos (109, 5")
-
cos
(too,s" * r, )]
p = 22,29"
Vt dq 2:8. DQng co DC kich tr} tlQc l4p c6 V6^ = 230V, Id^ =
rrdm = 500v/ph, R,r = 0.115d1 vh, Lu = 1lmH, drrgc cung cdp bdi mQt
chopper tdng rip. BQ chopper c6 V = 230V, tdn sd ldm vi6c 400H2.
co lAm viQc d ch6'tlQ hdm tdi sinh, tinh:
1- T6'c d0 dQng co vi c6ng sudt
Gie thi6t giit K@ = K(Da^.
trd v6 ngudn t4i Iu = Ia^ vd T = O
2- Ndu h€ sd di6u chinh nh6 nhdt cho ph6p T-in =0,1, tinh tdc
dai cho ph6p tld dQng co lim viQc an todn (Iu S Ia) vdi KiD6^.
Giei
1-
Tt thdng dQng co:
6q =Vr-- RrIo* - 230-0,115x90 = 4,!9
@d^
52,33
Vslra.d.
vdi In = 90A vd y = 0,5, sfc di6n dQng cfia dQng co ld:
E = (1 - y). V + IuRn = 0,bx 280+ 90x 0,115 = L25 V
Tdc d0 dQng co:
; =+
= 29,83 lrod,ts'l
KO=,",1
4.r9
n=288 t iphl
Tfnh
cOng sudt dgng c6 tuA vd lrrdi:
""
!
7u
=+=
! =z.s
f
1u
cu_
38,3
T '
= 0,026;
(!
P=t
P, -r)'rr- i*7,
[V
!-
95,65 [nzs]i
_(t-r)
9
\t
r
_ft
-T
+e ril'rt -, etu -l
r-
T
--i -1
It _'
lnsl
clQ
otEu xutEr,t r6c o0 o2Na co M)r cutEu
87
2- Dd dQng co lAm viQc an todn, Iu 3 16^. T6'c tlQ crtc dai cho ph6p
cria rlQng co tfnh duoc vdi T = y -in vd ,I7 = Id^. V6i tdc d0 llm viQc l6n hcm
l,0c tlQ ndy, dbng .I, sE ldn hon I7* vd khdng thd didu khidn drroc (vi khdng
t,hd girim y hcrn nra). Srlc rliQn dQng cria ddng co vdi y = 0,1 vir /u = 90A:
E =(L-T).V +RuIn =(1-0,1)x280+0,115x90=217 V
suy ra:
0."*
=
n^^* =
+KO= 4,79
?\7= = n,a [radtsl
494
[ulPh']
Vl drr 2.9: DQng cd DC kfch tU tlOc lap c6 V6^ = 250V, Ia^
= 2OA,
SQQv/ph, Ru = 2,5d1, drroc cung cdp bdi mdt bQ chopper c6 diQn dp
vdo V = 250Y, tdn sd ldm vi6c 400}J2. BQ chopper hoat ddng d g6c
phdn trr I.
It,1,,,
=
1196
1- Tinh h€ s6' di6u chinh 1 cdn thict dd t6'c d0 gidm xudng cbn
400v/ph vdi tii dinh mrlc.
2- Tinh gi6 tri diQn cdm nh6 nhdt cria mach phdn ftrg ad dem b6o
rlryn s6ng ddng phdn rlng < 7O7o 16^
(irii
1-
Til th6ng dQng co:
rr
Ka ='d^ - RuIa^ - 250-2.5x20 = 3,18 [Vstradl
adn
l0x2n
Srlc diQn tlQng cria dQng co
E = K@a=
khi n = 400 v/ph:
s,ls"+#
= 183
DiQn rip cung cdp cho phdn rlng dQng co
V4 =
RtIu
+E
=2,5x20+
He sd didu chinh y cAn thidt
2- Ta c6 c6ng thrlc
""
C6
=
khi
V
d6:
133 = 183
, , =+=
#
V
= 0,73
tinh don s6ng dbng dQng co:
V ff *
z4;
n-Tttu
-s-frtr,t -"-(r-t)Ttr,,l
t-
"-n'
1
thd chrftrg minh drrgc Aio dat cqc dai khi y = 0,5, khi d6:
88
Theo diCu kien dd bdi, dgn s6ng dbng cuc dai
qud
LOVo
/ru-
kh6ng drroc
16^:
x <
'y
*=:-
L0%I,r
I| <
l}%Idn
2Rnl+
Vi dq 2.10. DQng cd DC kfch trl ndi tidp c6 Va^= 220Y, Id^= 100A. D
trd phdn fng: 0,06Q, di€n cdm phdn fng: 2mH, di6n trd cuQn kich
'0,040, diQn c6m cuQn kich tt: 18mH. Ddc' tinh til h6a cria dQng co
n = 7O0v/ph cho trong bdng sau:
(dac tinh do duoc blng crich cho dQng cd hoat dQng nhrr mQt mdy phdt
chc'd0 kh6ng tdi: d6ng co drloc quay bdi mQt dQng co so cdp va cuQn ki
tr] tluoc cdp diQn til mQt ngudn ri6ng. sric criQn dOng E drroc do tr6n
phdn rlng). DQng co n6i tr6n drrgc cung cdp til mOt b0 chopper tdn
OOHz, cliQn dp ngudn 22OVDC.
Tinh t6'c dQ tlQng co khi
T
= 0,7 vd m6men t6i =
Gi:ii. T6'c d0 tai tl6 d{c tfnh til h6a drroc do:
DiQn :ip cdm rlng
M6men:
khi
ar
LBO
Ma^.
='OO^l'n =78,3 [rad.tsl
60
d6:
E=KQ1n - K^=Ke=E
o)
M=KQI,=K^Iu
TrI cdc cOng thrlc tr6n vd d6c tinh tir h6a cfia tlQng cd, suy ra:
M6men dinh drrlc (tqi Iu = 10OA) = 242 Nm.
l50Vo M6^ = 1,58x 247- 370,5 Nm
C6 thd suy ra dbng trrdng rtrg vdi lSOVo M6^tU b6ng I{W e tr6n (vi dU
qua tld thi IuM) hodc bxng c6ch noi suy). Dbng phdn ring khi d6: /,r 1BBA.
=
HQ
sdK- tai
L50vo
M6^: K^
=Y=ry
rt 131,
=2,79
[Vslrod.]
89
,p
=
TV -=I
uRt
K^
-
0, 7 x
220 :-133 x 0,1
2,79
= 50,4 radls
n = 48L,3 lulphl
Vi dq 2.r1: DQng co c6 thdng sd nhrr d vf du 2.8 duoc cdp ngudn tir mQt
bQ chopper kidu d6o dbng (hoat dQng d phAn tu I vd II). BQ chopper drroc
cung cdp tr} ngudn V = 2}OYDC vA tdn sd hoat dQng c&a bQ chopper li
f = 4OOHz.
1- Tinh t6c d0 dQng co khi hoat clQng d chd d0 dQng co v6i y = 0,5 vi
M = l/2 Ma^.
2- Tinh tdc clQ dOng co khi hoat d6ng d chd d0 hdm tdi sinh vdi
Y=0,5vd,M=Ma^.
ciii. 1K@ = KQa^ =4,L9 [Vslrad]
Srlc diQn dQng ctia ddng co khi hoat dQng d chd rlQ dQng co vdi
y = 0,5 vd. M = Vz M6^ (nghia ld Iu = 0,5 Iy6^):
E = TV - RuIu = 0,5x230 - 0,115x45 = 109,8 V
TOc d0 d6ng co
khi
d6:
E 109.8
t=ft'=-ffi=26'2
lradlsl
=250,4 lul phl
2- Khi hoat dQng 6 chd d0 ham tdi sinh v6i M - Ma^ thi .I/ = -Id^.
VQy sri'c rliQn dQng cfia dQng co khi d6:
E = TV - RuIu =0,5x230 + 0,115x90 = t25,4 [Vl
n
TOc tlQ d6ng co:
E
L25.4
'=ft'=ffi=29'9
lradlsl; n=286
[ulPh)
Vt dq 2.r2: DQng cd DC kich tir dOc lap c6 Va^ = 280V, Ia^ = g0A,
na^= 500v/ph, R,t= 0,115C), L,t= lI mH. DQng cd d6dc cung cdp bdi bO
chopper l6p E, di6u khidn theo cdch 3. Ngudn DC cung cdp cho b6
chopper la 230VDC, tdn s6'ldm viQc cria bQ chopper ld 400 Hz.
1- Ndu y€u cAu tlQng co ldm viQc 6 phdn trr
II
vdi M = Ma^ vd
CHUONG
2- Ndu y6u cdu dQng co ldm viQc d phdn tu III vdi M = tl2Ma*
n - Oov/ph, tinh hQ sd didu chinh 1.
(Gia thidt tt th6ng tlQng co gif, kh6ng ddi vd blng tlfnh mrlc
qud trinh tlidu khidn)
ci'ii. 1- Tt th6ng dQng co:
yq =Va^ - RuIa^ - 230 - 0,115x 90 = 4,79 lVslradl
500x
@d^
2rl60
n = 300v/ph:
2nx300
Srlc diQn tlQng cria dQng co n6'u
2nn
(D=60
60 =-=31.4
lrad.lsl
E = KQrl=4,19x37,4 = 131,6 V
BQ chopper ldp
E tlidu khidn theo cdch 3 c6 ddng phdn fng
binh tlrrgc tinh theo c6ng thrlc:
Iu=
dQng co lhm viQc d phdn
2v (y-0,5)- E
Rrt
tu II, do d6 Ix= -90A (vi M = Ma).Ta
2x230(y - 0,5)- 131,6
-90 =
1-
Tai n = 400v/ph,
0,115
+
Y
c6:
=0,76
srirc diQn tlQng cfia dQng co:
t-2nx4oo
60
=
41.g [rad.lsl
+ E = K@<o= 4,19x41,9 =175,4 V
Ndu dOng cd lam viQc d phdn tu III vdi M = Vz Ma^, ta c6:
-45 -2x230('t
:
9:5-_)+L75,4 =+
0.115
T = 0,11
sAr rAp
2.1. DQng cd DC kich tU dQc lap c6 th6ng s6: V6^ = 230Y, rtdm = 500v/p,
Ia^ = 4oA, Ru = 0,478{1, Pd^ = 7,46kW' DQng co tluoc cdp tliQn
mOt cdu chinh hnr mQt pha didu khidn hodn todn. DiQn 6p ludi 230V
60Hz cung cdp cho cAu chinh hnr qua mqt bidn 6p mQt pha. GiA
mach phdn rftrg c6 cliQn khdng dfi l&x dd dbng qua dQng co ld li6n
vdi mOmen tAi ldn hon SOVo m0men tlinh mrXc cria dQng co. DiQn trd
vd ili6n kh6ns cia ngudn vh bidn 6p c6 thd b6 qua. Ddng kich tU git
KHTEN
t)
b)
rdc oQ DeNG co
MOr curEu
DQng co cdn drrgc cung cdp cliQn dp rlinh mrx'c khi <ldy tai, hdy
chon bidn rip thich hgp nhdt troug ba bidn dp sau:
L) 230/260V
2) 23012L0V
3) 230/400V
Vdi bidn dp dd chon d tr6n, tinh:
kich cld dQng co ldm viQc vdi m6men dinh mrlc & 50vo t6c
tlQ dinh mrlc
1) G6c
niy duoc d6o chidu dd lim viQc d chd ttO
hdm tdi sinh. Tinh g6c kich cdn thidt dd m6men dQng co la dinh
mrl'c 6 300v/p. 86 qua ma sdt tr6n truc tlQng co.
2) Phdn dng dQng co hic
Lam
lai bdi
1 vdi cdu chlnh lrru tic ndy ld cdu chinh hnr mQt pha rlidu
khidn brin phdn. 86 cdu b-ii/.
kich til doc lqp duoc cung cdp b&i mOt cdu chinh lrnr mQt
pha didu khidn bdn phdn. cuQn kich tu cia dQng co ciing duoc cung
cdp tr} mQt cdu chinh lmr m6t pha di6u khidn bdn phdn kh6c. DiQn rtp
kich tir giir d mrtc cyc dqr. Ngudn AC c6 th6ng sd zosv/ooHz. DQng co
c6 R,, = O,lzdt, di6n trd cuQn kich tir la 2200. HQ sd Knt
= l,Olb y/A_
rad/s. DQng co lam vioc vdi m6men tai le zbNm tai 7o0v/p. 86 qua
tdn hao do ma sdt. Dbng kich tt vd phan fng rd li6n tuc vd ph8ng.
Tinh:
DQng co DC
a) Ddng kich
til
b) G6c kich cAn
thidt cfia b9 chlnh
lrru
c) H€ sd c6ng su61 ng6 vdo cria bQ chinh
lur
(Lur y: K<b = KnIn)
rad/s. DQng co ldm viQc vdi g6c kich 4bo, ddng phdn fng bbA. 86 qua
tdn hao do ma sdt. Ddng kich til va phan fng la liGnluc ve phEng.
Tinh:
a) M6men dQng co
b) Tdc dQ dQng co
c) HQ sd c6ng sudt ng6 vdo cria b0 chinh lu-r
2'5. Ndu cdc tfnh srl'c diQn dgng cria dQng co dang hoat dQng
d cau b,
duoc dAo chidu nguoc lai (vi du: dirng b6 contact tl6o
chidu diQn
cung cdp cho phdn ring dQng co), hdy tinh:
a) G6c kich cdn
thidt cria bQ chinh lrru cung cdp cho phdn rlng
dd ddng.I, tai thdi didm drio chidu lA 55A.
b) C6ng sua't dgng co trri vd ludi khi d6.
Gie thidt kich
tt
gifr nguydn nhrr d bdi 2.4.
2.6. DQng co DC kich tir dQc l{p c6 th6ng s6: V6* 800V,
nd^ = 7
=
Er = 0,35C), Pd^ = lbkw, diQn trd cu6n kich til ,Rpl 250{t.
=
drroc cdp di6n bdi mQt cdu chinh ltnr ba pha didu
khidn hodn
Cu6n kich tir ciing drrgc cung cdp tr} mQt cAu chinh lur.r
ba pha
khidn todn phan vdi g6c kfch chinh sao cho 6p ra cria cau
chinh I
crlc dai vd gitr nguyOn trong sudt quri trinh didu khidn
t6,c d6.
dien AC cung cdp cho cdu chinh lur c6 th6ng sd: ba pha,
6OHz,
pha 208V. HQ s6 Ke1= 1,15 V/A-rad/s. Ddng phdn
rrng vd dbng kfch
gi6 thidt li li6n tuc vd phEng. 86 qua ma sdt vd tdn
hao kh6ng
HAy tfnh:
a) G6c kich a1 cria bQ chinh luu cung cdp cho phdn rlng,
ndu dQng
lAm vi€c vdi tdc d0 dinh mfc vd cung cdp ra tai c6ng
sudt di
mf'c.
b) Tdc d6 kh6ng tdi cria dQng co ndu g6c kich a1 gitr
nhrr d c6u a
ddng khdng tdi cria dQng co ld LOVo dbng rlinh mrfc.
c) G6c kfch cr1 cfia b6 chinh lrru cung cdp cho phdn fng,
n6'u tr6ng
ldm viQc vdi 25Vo t6'c d0 dinh mrlc vd.1,, [o^.
=
d) Ndu y6u cdu hQ thdng ph6i d6m bio kh6 ndng qu:i tAi
vd a;o = o)d.m, tfnh pham vi didu chinh t6'c d6 D.
M^u = )[a[,
(Dinh nghia D = o;.*/ro.i,, tei I,r Ia^)
=
2.7. Lirm lai bdi 2.6 ndu cric bQ chinh lrru cung cdp cho phan
rhg vd ki
tir cria dQng co hic ndy li chinh hn ba pha cdu didu khidn b6n phdn.
2.8. D6ng co DC kich tir d6c lAp c6 th6ng s6: V6^ b00V,
Ia^ = 60t
=
Ru = 1,5d2, drrgc cung cdp bdi mOt b0 chinh hnr k6p ba pha.
DiQn d
pha ngudn xoay chidu cung cdp cho cdu chinh lurr ld
420v,50H2. GiA
thidt sut dp tr6n
KHTEN
r6c
oQ oQNa
co MQr cnEu
a) DQng co hoat tlQng d chd tlQ dQng co vdi ddng tdi tlinh mrlc vA
diQn dp cung cdp cho dQng co ld 450V.
b) DQng cd hoat dQng d chd tlQ hfrm tdi sinh vdi ddng trii dinh mric
vA diQn dp cung cdn cho dQng co ld 450V.
c) DQng cd hoat dQng d c}id aO hdm ngrtdc vdi dbng tdi tlinh mrlc,
rliQn dp cung cdp cho dQng co ld 400V vi diQn trd phu trong
mach phdn fng ld 0,5O .
tt
ndi tidp c6 Vd* = 600V, diQn tr& tdng cria phdn
dng vi cuQn kich tU le 0,160. Dbng qua clQng co ld 210.4. khi hoat
dQng vdi tdc d0 600v/ph. DQng co mang tfui c6 m6men bidn thi6n tdc
dQ cho bdi c6ng lhltc: M" = Aro2.
DQng co dugc cung cdp bdi mQt cdu chinh lur ba pha didu khidn
todn phdn. Gie thidt mach til dQng co c6 thd coi lA tuy6h tinh vd
dbng qua dQng co lA li6n tUc vd ph8ng. Hdy tinh:
a) Gid tri cria A, ndu dQng co hoat dQng vdi tdc dQ 600v/ph vdi dbng
phdn rlng la 210A.
b) DiQn :ip pha cria ngudn xoay chidu cdn cung cdp cho cdu chtnh lrru
ndu mudn dQng co hoat dQng vdi tdc dQ 600v/ph tai g6c kich c = 0.
c) Ddi didu chinh g6c kich cr dd tdc dO bidn thi6n tr} O tldn 600v/ph.
DQng co DC kfch
kich tr]
lfp
c6 th6ng s6 P6^= 2,2kW, Vd*= 22OY,
Ia^ = LL,6A, rldm = 1500v/ph, Ru = 2d2, Lu = 32,5rnlL DOng co duoc
cung cdp tU mQt bQ chopper kidu gi6m 6p c6 tAn sd d6ng c6t Id
600H2, dien dp ngudn cria b0 chopper le,220V. DQng co mang tAi c6
m6men tl lQ thu4n vdi tdc tlQ. Tai T = 0,9, tdc tlQ dQng co ld 1260v/ph.
DQng co DC
Tinh gid trf 1vd
dQ
tlOc
don s6ng dbng n€u dQng co ldm viQc vd'i tdc
tlQ
800v/ph.
tt
ndi tidp cd Vd^ = 220V, /a. = 100A, Ru = O,OOC),
Ru = 0,04d2, L,r= 2mH, Lkr= 18mH. D{c tinh tU h6a cria dQng cd khi
do d tdc tlQ 700v/p (btng c6ch cho tlQng co hoat dQng nhu mdy phdt
kh6ng tAi, kich tU tlQc IQp) cho trong bAng sau:
DQng co DC kich
Ddna ktch tU (A)
Di6n dp ra (V)
25
50
66.s
124
75
158,5
100
't25
181
198.5
1s0
211
175
221.s
2.12. DQng cd DC kich tr} dQc l4p c6 dinh mr1c 230V, 1000v/ph, 20A,
tr& phdn ri'ng 1f), cliQn crim phAn rlng 50mH. DQng co drroc cung
bdi b0 chopper ldp B (che dQ hnm t6i sinh) v<j'i tdn s6' hoat
500H2.
a) Tinh tdc dQ dQng co vd c6ng suat dEng co phrit ra vdi y = 0,5
dbng phdn rl'ng lh dinh rnti'c.
b) Tinh d0 don s6ng ddng crtc dai
fti
nh6 nhdt cua y ld 0,2. Tinh tdc d0 an tohn crlc dai
ddng phdn rlng kh6ng vrro-t qud dinh mrlc.
c) Ndu gi6
Ndu ddng kich tU gizim cdn 80alo dinh mri'c, tinh t6'c d0 an tod.n
dai ctia dQng co khi d6, gid thidt quan hQ gitra tr) thdng d6ng co
dbng kich tU ld tuydn tinh.
2.13. DQng cd DC kfch tr] noi tiep d bei 2.11 drtoc cung cdp boi bQ chop
lAm viQc d chd dQ ham t6i sinh. Di6n rip ngu6n cung cdp cho
chopper la 220VDC.
t6'c d0 d6ng co vdi y - 0,5 vd rnOmen tzii bXug 2 ldn
dinh mrl'c. 86 qua tdn hao ma sdt vd quat gi6.
b) Tinh y ndu dQng co hoat d6ng d 500v/p vd m6men tai
m6men dinh mfc.
a) Tinh
bX
2.14. DQng cd DC kich til alQc ldp c6 cdc giri tri dinh mrlc: 7,46kW,
500v/p, 40A. DiQn trd vh diQn crim phdn rlng d6ng co ldn lrrot
0,478Q vd 13mH. DQng co dttoc cung cdp bdi bQ chopper ldp D,
sd d6ng cdt 400H2, ngu6n cung cdp cho b6 chopper Ie 230VDC.
a) DQng cd dudc hdm dilng til tdc d6 500v/p bhng him trii si
Vdng didu khidn ddng diQn trong hQ th6'ng s6 thay ddi 1
cdch trr tl6ng cld duy tri dbng hdm bing dinh mf'c. Quri tri
him xdy ra ch{m vi c6 thd gi:i thiCt ld dQng co o chd dQ xric
tai moi tdc ctQ. Tinh vd v6 sr.r thay d6i cfia 1 theo tdc dg clQng
b) Ndu tlQng co hoat dQng d g6c phdn tu I tai n = 300v/p. Tinh
tri y khi Iu = 54.
c*ong
l\
3
^?
DtEu KHIEN vONG KiN DONc cd Dc
Khi sai sd tinh cria
truydn d6ng vdug hd d6ng co DC kh6ng thd
[hdn mdn y6u cdu cilra hQ truydn d6ng, d6ng co DC s6 drroc didu khien
llroo kidu vdng kin (closed-loop). Khi dd, c6c vdng hdi tiSp se drroc st?
rlung dd han chd cric thdng sd cdn di6u khidn trong d6ng co o mri'c gidi
Itqn an todn, ddng thdi nang cao chdt lugng drip ri'ng qu:i dQ cria h6 thdng.
hO
Trong chuong nhy sE khrio srlt ho di6u khidn toc dQ dQ'g co DC theo
hi6u vdng kin didn hinh. cdc hd truydn dOng c6 cdu hinh nhu vay drroc srl
dyng rQng rdi trong cOng nghiOp tir c6 1+ 10.000kW hodc cao hon. HQ
[ruydn ddng chinh lrnr - dQng co DC sE ddoc phan tich vi h6 loai ndy drroc
rrl dung rdng rdi trong cdng nghiQp hon hO chopper - dOng co DC. Tuy
rrhi6n, cdu hinh tudng tu c0il.g rip dung cho hQ chopper - dQng co DC.
3.1 sd Dd xndl rdr,rc ouAT nE rn0'ruc stEu rnrEN vONc
DoNc Cd
KiN
DC
MQt he di6u khidn t6'c dQ dQng co DC didn hinh vdi hai vdng didu
khidn duoc gid'i thiQu trdn hinh 3.1. Cric vdng di6u khi6n bao gdm vdng
didu khidn dbng cliQn (goi td,t: udng d,dn.g dian.) vit vdng didu khien tdc
d0 Gq, tdt: udng t6c dQ).
T6'c d0 ctia hQ th6'ng duoc h6i tidp, thudng ding mriy phrit t6c, vi
duoc loc b6 cric don s6ng AC bang mach loc. Tin hi6u ndy drJoc so siinh
vdi tin hi6u tdc d0 det (r)r/, vd sai s6'toc dQ drroc khudch dai qua rnach
hiQu chinh vdng t6'c dQ. Mach hi6u chinh ndy c6 th6' ld khdu ti le (P)
ho4c ti l€ - tich phdn (PI). Mach hiQu chinh vdng t6'c dQ ding hhdu PI
c6 ba muc clfch: dn clinh hQ thdug vd hi6u chiuh h6 sd dQm ctia drip ri'ng
quri clQ tdc clQ d gidi h4n mong mu6n, girip dat sai sd tinh gifra t6'c dQ
CHUONO
Ngu6n 3
BO chlnh luu
chlnh Khau
dQ b6o hda
KhAu hi6u
tiic
KhAu hi€u chlnh Mach ktch
ddng di6n
Hinh 3.7: HQ thdng didu khidn udng hin d6ng co DC - b6 chlnh luu
Ngd ra cria khau bdo hba vbng didu khidn tdc ilO ding lam tin
,
ddt cho vdng di6u khidn dbng cli6n. Tin hi6u nay kdt hop vdi vdng di
khidn ddng diQn nhxm han ch6'ddng phdn rlng d6ng co d mrlc cho ph6
trong qud trinh qud rlQ. T6c d6ng cfia vbng dbng di6n s6 duoc kh6o
chi tidt d phdn sau nhung c6 thd gi6i thich v6n t&t: r<hi Iu 1 I^o,,
d.6: I^* ld dbng phdn fng crr. c dai cho ph6p, vdng hdi tidp ddng
6nh htrdng l6n hQ thdng vd d6p rlng hQ th6'ng quydt dinh bdi vdng
d0. Khi sai sd tdc d0 ldn hon mt?c ndo d6, ng6 ra kh6u bdo hda s6
mfc gidi han, khi d6 dQng co s6 duoc didu khidn theo vbng hdi
ddng, nghla ld dbng dQng co s6 duoc duy tri d mf'c crr. c dai cho ph6p.
Didu niy girip ttdp rlrrg tdc do dOng co di6n ra nhanh ddng thdi gidi han
dbng phdn tng 6 md'c q4 toan eho ph6p. Khi sai sd tdc dQ gi6m xudn
drrdi mri'c ni.o d6,
lfc ndy vdng tdc rlQ mdi c6 t6c dQng trd lai l6n ddp
hQ thdng.
3.2 HAM TRUYEN cAc
1- DQng eo DC
hieh
pTIAru
tt
rfr
dQc
lep
Gia thidt kfch tt dQng co rluoc gitl kh6ng ddi, ta c6 m6 hinh dQng co
DC kich tr} dOc l{p m6 td tr€n hinh 3.2a. Ngodi ra, ctng gia thidt mach
til dQng co lA tuydn tinh.
KHIEN V1NG KiN DQNG
ca
DC
Hlnh 8.2: Hd,rn truydn dQng co DC
Phuong trinh mach vbng diQn 6p cho phdn fng d6ng
a
ud=e+Ruiu+ Lndlu
-dt
e=KQro
hong tlo:
Phrrong
trinh
cdn
(3.1)
(3.2)
blng m6men tr6n truc
dQng co:
m= m"+B,,*;4
(3.3)
dt
gd6:
J-
co:
rn=KQIu
(3.4)
m6men qudn tinh tlQng co vd. m6men qudn tinh cria hQ
thdng quy ddi v6 truc dQng co;
B - hC sd ma sdt; rn" - m6men c6n quy ttdi vd truc dQng co.
Ap dung bidn ttdi Laplace, cdc phrrong trinh (B.l)+ (8.4) trd thinh:
'
V(s) = EG) + R"I"(s) +
E(s) = KA e{s)
LaI{s)
(3.5)
(3.6)
-
TU (3.5), suy ra:
trong d6: ru =
Lr_
Ru
thbi hing phdn fng (thdi hing diQn til) ctia dQng
Til bidu thrlc (3.7) suy ra:
ro(s)
trong d6:
.I
t* =
;
-
ItttG) -M"(s)l
I
-
(8.
- thdi hXng co cria h6 thdng.
cdc quan hQ ndy c6 thd bidu di6n bing so d6 khdi nhrr hinh 8.2b.
Trr hinh 3.2b c6 thd suy ra quan h6 gifra tdc do to(s) vdi di6n
phdn fng Va(s) vd mdmen tdi M"(s):
ro(s)=
trong d6:
r*7ffivat"l
+
.*.ffi,M"(s)
11
nu
G,(s)
- = 1+ sr,,(Ka)1 +Bsr_
H{s)
= K@
(3.11
(3.1
I
GzG)= - B
I+sTm
(3.
r
(ro)2
D
Hz(s) =
r+sT/
(3.1
Bidu thrl'c (3.11) cho thdy tdc dQ o(s) li x€p chdng cria drip rlng
dQng co vdi tin hiQu vdo ldn lrrot ld, VaG) vd, M"(s).
X6t drip fng cria tdc
dQ d6ng co o(s)
vdi di6n rip phdrl.rtng V,tk) 0
nAy, xem M"(s) = 0). Tt cric bidu thri'c (3.11), (8.1la) vd (8.11b), ta c6:
o(s)
KA
(3.1
ItEu xut4t't vorue,xln;&ttc-oo Dc
99
<<c- (didu'ndy xdy ra trong hdu hdt cdc trrrdng hgp trong
thuc to, nhrr'vQy tu c6 thd b6 qua vi bidu thrlc (8.12) drroc don gian lai
lhu sau:
Ne'u ro
o{s)
V2(s)
-=
KO
(Xa)t +RuB+sRuBr^)
irong d6:
(3.12a)
(3.12b)
h^=
KO
(ro)2
+ RuB
ta1 I 'lp
(3.12c)
(3.12d)
Tt hinh 3.2b:
KO
o{s) E
=
/r(")
1+s%
k*,
-= 1+"%
(3'13)
Do d6, tr} cdng thrlc (3.12) vA (8.18), suy ra:
g*&9 k*B(r+ sr^) h^r(r+sr^)
+i"]
V4(s)= Va(s) c,{s) -- Ko(l+st-1) -- -11a"r_rt
(3.14)
vay, nhlm muc dich d6 ding cho vi6c gi6i tfch hoat d6ng cria hQ
ihdng trong tnrdng hop chl x6t anh hudng cria diQn dp phdn rtug l6n tdc
d0 (xem M"(s) = 0), clQng co c6 thd bidu di6n bdi hai kh6'i ndi ti6'p nhu
hlnh 3.2c. Cdc h€ sd h* h^t, k*z clrroc bidu di6n theo c6ng thrl,c:
(3.14a)
(3.14b)
(3.14c)
Trong trrrdng hop x6t ddn t6c dQng cria m6men tfui M"(s), so dd khdi
hlnh 3.Zb drroc sfi dgog.
2- Hdm
truydn
ddi
Thdi hlng ciia bQ chlnh lrru c6 ttidu khidn thay ddi theo diQn dp rti6u
lhidn, vi du: vdi b0 chlnh lnr cdu mQt pha ttidu khidn hodn toan vd tdn
fd dp cung cdp ld 50H2, thdi hlng ndy bi6-n thi6n tir 0 ) 10ms. Tuy
bQ bidn
100
X6t chinh lrru cdu didu khidn hodn todn, diQn :ip trung binh ng6
lrrr.r vdi eia thidt dbng chinh ltnr lh li6n tuc cho bdi c6ng thfc:
Va = Vao cosoX6t tn/dng hop ddng bQ dang cosin, nghia ld di6n :ip ddng bQ
cria cdu chinh
bdi c6ng thri'c:
U66
= V66^ CoSrit
(3.
Goi di6n dp ttidu khidn bQ chinh lur ld u6p, g6c kich cr xAy ra
Ud,k = Udb, nghia lh;
(3.1
= V66;, COSOL
Til c6c bidu thri'c tr6n, c6 thd suy ra hdm truydn cfia bQ chinh
alidu khidn hodn toln:
%(s)
(3.1
=nuo
U6p
ffi
Trong tntdng hop chinh hnr cdu didu khidn kh6ng hoA.n toin,
gi6 thidt ld ddng chinh lrru li6n tuc vd. diQir dp ddng b6 c6 dang:
udb=Vdb^(1 + cosot)
(3.1
C6 thd suy ra hdm truy6n cfia bO
chinl luu c[ng Ia h]ng sdnhu (9.16).
Trong trudng hop tli6n dp ddng b6 ld dang rd,ng cua, tl sd girta V7
V6e thay ddi theo gi6 tri cria di6n 6p didu khidn. Lric ndy, vin c6
bidu diSn him truydn bQ chtnh lrru theo (8.16) v6i K66Ia trung binh gi
tri so'ldn nhdt vd nh6 nhdt cfia ti sd Vd
van
chinh
KhAu hiQu chtnh thubrg
d.yns h khdu tl lQ (P) holc ti
le " tich phen eI).
3- Kh6.u hi?a
Hinh 3.3 bidu di6n
khAu ti 16 tich phAn kdt hop
vdi kh6'i cQng trrl vA khdu
+Vr
-v2
b6o hda.
Hdm truydn khAu pI
tr6n hinh 3.3:
tin hiAu + khdu
bd,o hda
KHIEN
voua xitt o2tto co Dc
t1,"
KHAo
= R2Q;
ftp
R2
=
(3.18b)
RL
sAr rE rH0r'rc srEu rnrEN vdNG riru s0Hc cd Dc
I
KhAu hi€u
chinhi
io"io
'u"n
i
KhAu hiQu
chlnh
;;;;;;6;
^.
-1,_L
BQ chrnh
.
..
l1
^"--i
":l:f:
KhAu hdi tidp tdc ddng
Hinh 3.4: So d6 khtii he thdng udi khd.u hiQu chlnh vdng
tdc dQ ld. khd.u fi Ie P
He thd:rg vdi hai vbng hdi tidp c6 so dd khdi nhu hinh 3.4a, trong
dO nrau hiQu chinh vbng dbng diQn gi6 thi6t sfi dr;ng khAu tl lQ vdi he sd
lrhudch d.ai kr KhAu hiQu chlnh vbng tdc dQ bao gdm cri khAu b6o hba,
nghia la khi tin hi6u sai lQch tdc dQ ng6 vdo cfia khdu hiQu chinh ldn
hon mqt mrlc ndo d6, ng6 ra cfia kh6u hiQu chinh s6 girl nguy6n 6 gi6 tri
ofc tl+i YIm.
Dd giai tich, ldn lugt x6t ddp ilrg ng6 ra cria hQ thdng vdi ng6 vho ld:
- Tdc d0 dilt ata9), khi d6 Mc(s) = 0
- M6men cln M"(s), khi d6 c&(s) 0
3.3.1 Xdt hQ
thdng vdi
rrra
Trong phdn niy s6 kh6o s6t t6c dQng cria vdng didu khidn
ddng
vbng di6u khidn tdc dQ. Ddp rlng cria tdc
hC
thdng khi M"(s) = O tl
dO
chdt lA tdc dQ kh6ng td;i ctnhQ th6'ng.
Trrrdc hdt x6t vdng h6i tidp ddng ddnh ddu blng drrdng n6t
drlt
hinh 3.4a. Til so dd khdi vbng hdi ti6.p dbng suy ra:
h'ku k^r:::^t
/,r(s)
yrG-t =
trong
d6:
l+
k^u .kta .k^t
1+ t-s
1+ t-rs
Kr" =
-]L!u:kqL+ k* .kr .kbd .k*r
(3.
Tn2=
-
r^ .knrr kt .ku .k^, + t^t
L+kuu kr kbd.k^l
(3.1
Vi th6ng thr.tdng: knu.fu .k66.k^1 >>
dd th6a didu ki€n ndy)
NOn:
krc =
7m2
Tt
day suy
|
r
(ui dq; c6 thd chon k1 dri
1
h*
= lm
(3.:
IuG)
ra: t'rG-t=,.rc=E
-u-- - -1
(3
So dd khdi hC thdng ldc ndy s6 don gi6n nhu
hinh 8.4b.
Tdc dqng erto vbng didu hhidn d.dng
Khi tin hiQu sai lQch girta tin hiQu t6'c dO det vd tin hiQu tdc tlQ
tidp dri l6n (ui du: t<hi khdi dQng dQng co, thay ddi tdc dQ...), ngd ra
khAu hi6u chinh vdng tdc d0 s6 ld. Vr^. Theo (8.21), vdng
dbng di6n s6 duy tri ddng phdn rlng d gid tri:
Iu^ = K1g V1^
Nhrr vdy hoAn toAn c6 thd han chd ddng phdn fng 6 mrlc cho
ndo d6 blng c:ich tfnh chon c6c gi6 tri phr) hop cria Krc vd,
V1^.
Khi vdng dbng diQn tdc dQng vd han ch6. ddng phdn fng 6 mtc I,
vdng di6u khidn t6'c dQ bi "cdt" kh6i hc th6'ng vd t6'c d0 l(c
ndy chi p
thuQc vio ddng phdn ring. vf dg, khi kh6i dQng vd sai sd
tdc d0 e*
\
KHTEN
vdt'ta xiN o2na co DC
IYo'k*',
= s(l+ t_s)
o{s)
to(t) =
,ld
103
Ir^
(3.23)
k,r,z (7-e'tt"^l
(3.24)
Tdc dqtng efi.a vbng didu hhidn tdc dO voi hh6.u hiQu chtnh ti
rc @)
X6t khdu hiQu chlnh vdng t6'c dQ lA khAu tt lQ vdi h€ sd tt lC &,. Til
dd khdi hinh 3.4b, suy ra ddp rlng ng6 ra o{s) vdi tfn hi0u vAo rU(s):
(3.25)
kw
hz=
trong d6:
(3.25b)
1+ kn .k, .k^z.ktc
-
Ndu:
ta
(3.25a)
lm
-
17=
nAy),
.kn2.krc
l+ kO .k,.k*2.krc
ldn dd clat didu kiQn
'ko= 1
-kff
c6:
(3.25c)
7m
7^=
-
kft
Theo (3.25) vA (3.25a), ndu
lQp, d,6p rtng tdc d9 6 ng6 ra li:
(3.25d)
.hr.k^2.krc
tin
hiQu rtdt
o16
ld hdm ndc, 6 chd dQ xdc
to(t=-)' = k''k^2'hlc
ad
1+ kn .k, .h^z.krc
DAy
ld tdc dQ kh6ng tdi
c;fia hQ
@.26)
thdng.
Sai sd xdc lQp cfia tdc tlQ:
t*(t
Ctch
=
-)
=
(3.27)
l+ k, .k,.k^2.krc
Tdc d.yng crta abng di6u khidn tdc dO v6i hhdu hiQu chtnh
ph6.n (PI)
X6t khdu hiQu chinh vdng tdc dQ ld khAu
ham truydn
tn' &,(ll.st,),
8l*
tt
tl
fi
rc
-
lC - tich phdn (pI) vdi
sd dd khdi hinh 3.4b suy ra:
<'(s) 1
(1+
'ffi=6ffi?
trong d6 rz tinh theo bidu thrlc (3.25b).
r,
.s)
(3'28)
CHUONG'.
Theo (3.28), ndu tin hiQu d4t o6 ld hdm ndc,6 chd dA xdc ldp, d6
tlng t6'c dQ d ng6 ra li:
<,{t--) =$-
(8,
re,ft
Sai s6'x:lc
lfp
cria tdc
€*(f
3.3.2
X6t hQ thdng vdi
dQ:
=-)=0
(8.
Mo
Trong phdn ndy s6 kh6o s:it d6p rl'ng cria h6 th6'ng vdi t6i M,(s),
ndy ta xem ab = 0. D:ip rl'ng cia tdc dO theo m6men tili M,(s) lfc ndy,
f nghia vdt lf, ld clQ sut tdc khi mang trii cria hQ thdng.
So dd kh6'i h9 thdng lric ndy bidu di6n tr6n hinh B.ba.
Hinh 3.F: So d6 khdi hC thdng khi x6t dnh hu6ng crta M"(s)
XU he thdng voi hhd.u hiQu chinh vdng tde dQ td. hhd.u fi rc e)
Tir so dd khdi hinh 8.5a, suy ra:
IuG)
=
1r
n
I-xo.ar.(s)+h kaal-ku,r.InG)+k*(-ap <,{s)]}
r ,,^t fro+
ri(s)
= -l ---:
h.kaa.k..kr.tf
*t
H;A:kMTl
L
(3'31)
Vi: &r. kua.k,. k11>> K<D vA kt.koa.knu>>Ru, n6n bidu thfc (g.81)
c6 thd nit gon thdnh:
Rutfltrt
voNa xiN oQuc co DC
Suy ra quan hQ gifra c{s)
v}
M"(s):
(3.33)
d6:
I(
=
KQ'k''k'
1*
kwB
1
h-o= Ko reA
,q tuhtr =
B
*,
I^
=T,
KI
KA.k,.kft
Y7:
t: ,fit'
suy
ra: K = 1 + h,. kp. krc. k^z
>> 1, quan hQ gitra to(s) vd M"(s) duoc don gi6n thAnh:
-1
M"G)_ KQ .k.
"(s)
1
.hn .krc 1+
(3.34)
st,
t0i: M" - li hdm nd.c, gi6 tri xric ldp cfia o(/), nghla lA
nang tdi cria hQ th6'ng 6 trang thrii xic lQp, s6 ld:
dQ
sut tdc khi
M"
=-) - - KA.k,.kfi .krc
Nhu vQy, khi thidt kd, c6 thd chon gi6 tri cria k.
o0a h6 th6'ng nh6 hon mQt gid tri dn tlinh trrrdc.
to(f
(3.35)
sao cho dQ
XAt he thdng voi hhd.u hiQu chlnh vbng tde dO td hhdu
Ph&n (PI)
tt
sut
tQ
tO'c
- tich
Tr] hinh 3.5a, thay'khdu hi6u chinh vbng tdc d0 hic ndy ld kh6u
lC -
tictr pnan
o{s)
-@J1,,),
sT-
sau d6
rft ggn, ta duoc:
_ -Ir.knu
s
tuI"G)=
-
yi
-!-'P*'Ko .h,-kfi
<r{s)
@-
t
ti
KQ .ku nn
(3.36)
I
KQ .h, .kfl
<< 1, n6n bidu thric (8.86) c6 thd vidt lai:
_ -rr.knr
s
Ka.k,,.kfi l+r. *+9,.r]
(3.37)
106
trong d6:
T2=
hn .hu,.k,rz.htc
vdi: M,. - ld hdm ndc,
mang
tdi
vi
gid, tri xdc lAp ctia crr(t),
ld d6 sut toc
t:ii cfia hQ th6'ng <i' trang th:ii xric l{p, s6 ld:'ghia
,1,_. =1i^"M" -ru''l'nrt
s+o s KO.h,r.leS1 1+t,,..r*a,, .ar."2 -o
Nhrr vay, vdi khau hi6u chirrh pI ci' vb'g t6c do. d6 sut toc khi
cria h6 th6'ng d chd d6 xdc lAp s€ bdug zero.
drr 3.r. Mo hinh didu khien t6'c dQ dQ'g co st? du'g Matlab.
cho d6ng co DC kich tir d6c lap c6 c6c th6'g sd v6t ry
. M6men qudn tinh ctia r6to
. H0 sd ma sd.t cria hQ thdng co
. Hing sd hlc di6n d6ng
. Di€n tr<i phdn fng
. DiQn crim phAn fng
'hrr
(3'
m
sau:
./ = 0,01 kg.rnzlsz
B = 0,1 Nms
Ko = 6,61 Nm/A
ft,r=1C2
Z
= 0,5H
V,t
[yl
Th6ng sd nhqp (input)
.
DiQn rip ngudn cdp cho phdn
Th6ng s6'xuat (output)
.
T6'c d0 d6ng
fng
co
,,
Hdm truy6l theo c6ng th['c (8.12)
ro(s)
V7\s)
-=
KA
(Ka)" + R,, . B(t+ s. r,r)(1 + s. r,,,)
Ydu edu thidt hd
Ndu ho th6'*g kh6'g duoc thiet kd theo ki6'u vd'g kin, dQ'g co
c6 thd quay vdi v{n tdc 0,1 rad/s vd,i di6n dp lgO vio ld lV (didu ndy
drroc chf'ng minh bhng nr6 phdng h6 thoirg didu khieu vdng hcil. Vi
sd cric y€u cdu ddi v<fi d6ug co ld phzii c1ua.v vtii vqr. toc rno'g ,ru()*,
so to'c dQ xdc lap phzii thdp hon t%. cac y6u cdu khzic doi vdi dac ti
dQng ld dOng co phzii duoc taug toc dd' tdc clo xric lap caug s<fnr cd
tdt, troug trrrd'g hop
'dy chfng ta rnoug 'ruorr tho.i gia' thiet lap vei
t6'c ddt ld tha'p hon hoac bxng 2s. Do t6c d6 thrrc cao hdn t6t do
dat s
lim hrr hd'g thidt bi, you cau ddi vdi d6 vot lo ld tha'p hon |c/c.
KHTEN
vONa xir,t oQno co DC
. Thdi gian thidt ldp vdn t6'c thdp hon 2 gidy
- DQ vot ld thdp }n'on |Vo
. Sai s6'tdc
rlQ d
xic l{p thdp tron
LVo.
IItOng ddn
l. M6 ph6ng
khidn vdng hd
' L4p mQt m-file mdi dd nhdp th6ng sd d6ng cd, lurr trf, file (vi du
fdl tOn dcl.m).
hQ th6'ng di6u
+file
tl]ang
,I=0. 0l ;
B=0. l;
KPhi=O. 0I;
Ru=l;
Lu=0. 5;
I
.
L,flp mQt mod,el (g.le simul,ink) m6i vd lrru trfr (vi du vdi t6n
dc-uongho.mdl).
KPhi
(J'Lu!3+(J'Ru>(Lu'B)>+((E'Ru)+Kphi 2)
CHUONG 3
Trinh
Budc
t{ tgo m6 hinh m6 ph6ng
1: Tt thtr viQn simurinklcontinuous ggi khdi rransfer
Function; nhdp d6i chuQt vd quy dinh th6ng sd nhrr sau cho khdi ndv:
2: Tit thrr vi6n SimulbLh / Sources ggi
quy dinh th6ng s6'nhtr sau cho khdi ndv:
Budc
chuQt
vi
DtEu xutEN
Budc
voxa xitt
oONc
co
3: Tt thrr viQn SimulinklSink ggi khdi
workspace; nhdp ddi chuQt
chgn format ghi ld Arcay:
4: Tt thu
109
DC
Scope
vri
vd dnt t6n cho khdi To workspace Id w
To
vd
viQn Simulink / Signals and Systems ggi khdi
Subsystem; nhdn ph6i chuQt chon Block properties vd quy tlinh th6ng sd'
Brtdc
nhrJ sau:
LT2
CHUONG 9
. Nh{n x6t thdy c6 sai sd 6 x6c lAp vd
* Khdu hiAu chinh udn tdc dang pID
dQ
vot
16.
khri
cao.
. ThOm vdo hQ s6'Kp - 100; Kd = 1; Ki = 1 trong dcl.m
' Tit simulink lcontinuous ggi kh6i rransfer Function;
chu6t vd quy dinh th6ng sd nhrr sau cho kh6'i ndv:
hi6n m6 ph6ng vA v6 girin dd ddp rlng vAn t6'c:
nhdp d6i
KHTEN
voxa xlx o1rua co Dc
H
Clock
To workspace
tubeystem
+
1,4
((J'
Ru)
r (1u.8))s
+
((B.Ru)+ Kphi^2)
rllttrl
ttttttl
ttttttl
---{----t---t---t___t___r_
1,2
'l
a
E
0,.
€
o't
9.
0,+
t
o,2
0
0 0,1 0,2 0,3 0,4 0,s 0,6 0,7 0,8 0,9
1
Thdi gian, [sl
Ddp ring hQ thdng nhanh hon nhidu so vdi hQ thdng vdng kfn trudc
Tuy nhi6n dQ vot ld cao.
Thng Kd dd di6u khidn giAm dQ vot
Cho m6 ph6ng
lai vd ldy kdt
qu6:
_l---__,_-___
16'.
Thay ddi Kd = 19.
CHUONG 3
LT4
Nhrr vfly ta stl dung khAu hi€u chlnh PID vdi:
Kp=100; Ki= 200; Kd =10
Vi ds 3.2. HA truydn ilQng dQng cd DC - bQ chopper
KhEi ctQng Matlab 6 vdo Demo/Blocksets chgn Power system:
Graphics
Language
Gallery
More Examples
+Toolboxes
+Simulink
-Blocksets
CDMA Helerence
Communications
DSP
Dials & Gauges
Fixed Point
Motorola DDK
chgn frle chopper - Fed DC Motor Drive vd Run Chopper- Fed DC.
M6 te m4ch: DQng co DC tlrroc cdp ngudn th6ng qua mQt bQ chopper
chrta kh6a GTO T1 vd diode hodn ndng lrrqng Dl. DQng cd k6o tdi co ddc
trung bdi m6men qurin tinh J, hQ sd ma sdt, vi m6men tei TL'
Khau hiQu chinh dbng dang mach tr6 so sdnh dbng diQn do drrgc vdi
dbng ct4t vd tao xung d6ng c6t Gro sao cho ddng dQng cd theo s6t gid
tri d4t.
Mach vbng didu khidn t6'c d0 srl dung khAu hiQu chlnh
tao ra ei6tri dbng t14t cho mqch vbng dbng diQn'
DiQn 6p vd dOng drroc hidn thi qua c6c khdi tlo.
PI
dd
gttu xut{N voxa
xiu oONa
co
DC
115
Load lorque OC w.anim
(N m)
sHpt24ov
Speed controlle(
tr
More Inlo
M6 ph6ng
1- Chay m6 ph6ng. Quan sdt ddng d6ng co, di6n r{p
khdi dQng trdn cdc khdi.
vi
t6'c dQ hic
Khi kdt thfc thdi gian m6 ph6ng (1,5s), hQ thd'g dat trang th6i x6c
l$p, c6c gt4 t4 6 xdtc lap c6 thd ghi nhdn bhng cdch chon trrrdc d6:
2-
TVorkspace VOlSave to workspace/Final state" trong Simulation /Parameters.
3- Thav thd giri tri khong ddi wref vd rL brii hai hdm ndc vdi thdi
3ian b6t ddu khdc nhau. Tdc do dat thay d6i tu 120 ddn 160 rad./s rJ t = 0,4s
vA mOmen thay ddi tu 5 ddn 2b Nm 6 t = L,2s. chgn "workspace I/o/Load
from workspaceanitial state" trong simulation/Parameters. chay m6 ph6ng
lgi vA quan srit drip rhrg cria hO truyOn ddng.
Chl/;dng
cd l(H0ttc odnc B0 - DGu KHIfN
rdc D0 DONc cd KHoNc oONc e0
DONc
;J
A
-.
--4.
l\
bi0t ld DCKDB rdto ldng
c6 nhidu mr tlidm hdn so vdi tlQng co DC, nhrr khdng rldi h6i b6o
thrrdng xuy6n, clQ tin c{y cao, khdi luong vd qu:in tinh nh6 hon, giri
hon vd c6 khd n6ng lhm viQc 6 m6i trrrdng dQc hai hoqc c6 khri
chdy nd. Do d6, DCKDB drtoc stl dqng rQng rdi trong cdng nghiQp
tdt cA cric loai tlQng co klidc. Tuy nhi6n, cho tldn gAn tlAy, phAn
DCKDB drrgc sfi dung trong cdc trlg dung vdi tdc ilo kh6ng tldi, do
phrrong ph6p ttidu khidn tdc do DCKDB trrrdc tldy thrrdng d{t ho6c
hi6u sudt k6m.
Vdi sg ph6t tridn m4nh m6 cria kY thuQt bdn din cOng sudt cao
kI thuat vi xfi lf, hiQn nay nhfrng b0 didu khidn DCKDB dd duoc
tao v6i tldp rlng cao hdn vd gi6 thdnh 16 hon cdc b0 tlidu khidn dong
DC. Do d6, DCKDB c6 thd thay thd tlrrgc tlQng co DC trong rdt nhidu
dung. Dg kidn trong tudng lai gdn, DCKDB s6 drrgc srl dung rQng
trong hdu hdt cric hQ truydn tlQng didu chinh tdc d0.
Chrrong ndy s6 kh6o s6t t{p trung cdc phuong ph6p didu khidn
dO DCKDB ba pha. Ddc tinh crla DCKDB cfrng drrgc khAo s6t, nhung
tQp trung vAo sd ild trrong drrong cria dQng co vi cdc c6ng thrlc tinh
cAn thidt - chi tidt v6 phdn nbry c6 thd tham khAo th6m trong c6c
DQng co khOng tldng b0 (DCKDB), tlac
liQu v6 mdy tliQn quaY.
4.1 oAp UHc cOn o0NG Gd KHONG sdr'rc s0
DCI(DB ba pha c6 ddy qudn ba pha phia statol.'R6to cria
@ua co xoa - oAu xutflN rdc oe oeva co
KDB
vA duoc ngdn mach d hai ddu bdi hai vbng kim loai (ddng hodc
!ltom)' Dbng diQn cdm rlng hinh thanh tr6n ldng s6c r6to c6 cing sd pha
Vl s6'cuc tU nhrr phia stator.
Khi stator drroc cung cdp bdi ngudn ba pha can blng vdi tan s0.f,, tir
lrudng quay vdi tdc d0 0)66 s6 drrgc tao ra. euan hQ gifra tdc d0 c&a tu
lrrrdng quay vA tdn s6'/cfia ngudn ba pha li:
,,ruu
trong d6: p - s6'd6i
'
=
W- - q'
pp
(rad/s)
(4.1)
crr. c;
- tdn sd g6c cfia ngudn ba pha cung cdp cho dQng co: a1 _ 2n
f.
Ndu t6'c dQ quay cfia r6to la <o, dQ sai lQch giira tdc d6 tu trudng quay
'ttator vi tdc dQ r6to ld:
cor
(4t =
OJat - O) = S. AaA
trong d6 <4r g9i ld t6'c dO trudt.
Th6ng s6's goi li d9 trrlot, ta c6:
(4.2)
O),* -(rl
S= -s-
(4.3)
@at
ho{c:
a=(7-s)rha
(4.4)
Vi c6 tdc
dQ trrong tl6'i giira r6to vd tir trrrdng quay stator, di6n rip
cam rlng ba pha s6 dtroc sinh ra trong r6to. Tan sd ciia diQn
:ip ndy
vdi tdc d0 trudt theo c6ng
G).
=
ti
thfc:
s.a:tadls)
lQ
(4.5)
M6men dQng co sinh ra:
* = -tot
.@- .F^ .sin6.
trong d6: O- - til th6ng tr6n mQt cqrc, Wb;
F^ - gi6 tri dlnh cfia sfc tr} dQng (mml) r6to, A-vbng
6, - g6c lQch pha gifa srlc til dQng r6to (r6to mmf)
khe hd kh6ng khi (air_gap mrnf)
(4.6)
vd
Ddu trrr chl m6men tdc trQng theo hrrdng gidm g6c l6ch pha giita
til dQng r6to vA std trong khe hd kh6ng khi.
std
srl,c
Ddp fing.efio DCIAB O eh6 dQ tinh
Mgch tudng drrong mQt pha cfia DCKDB cho & hinh 4.ra, trong d6:
1-
M6men M bao gdm cA mOmen tdn hao do ma sdt, qu4t gi6 tr6n
t
clQng co.
Tdn hao ddng r6to:
s.Pa,
r6to
@.
Lrrgng s.P41 cbn goi ld c6ng sudt truqt' vi n6 tl lQ vdi d0 tnrdt s
-
3
R"I;'
= tdn hao ddng
cing mQt c6ng sudt di€n til Par.
TU c6ng thfc (4.16) suy ra:
rr
c6ng sudt
trtqt
(
s'Odb
Cdng sudt dien tir d4t crr. c d4i, vd trrdng rlng ld m6men diQn
dQng co d4t crr. c dai, tai d0 tnlgt sn:
til
(X,+X)2
Mdmen
crr.
c tl4i cfia dQng co (cdn goi
M*= z@ao
=3 -I
li
m6men
tdi han):
v?
Ddu (+) trong bidu thrlc (4.2L) vd (4.22) trlong rlng vdi chd d0
cd, cdn ddu (-) trrong rlng vdi chd t10 mdy phdt.
COng thric (4.22) cho thdy mdmen cuc dai cria DCKDB kh6ng
thuOc vdo gid tri cfia diQn trd r6to R'2. Tuy nhi6n, c6ng thfc (4'21)
thdy etf tri cria s- tl lQ vdi gi6 tri diQn trd rdto cfia dQng co. C6ng t
(4.L2) vd (4.21) ciing cho thdy gtf tri cria ddng r6to t4i didm momen
crr. c d4i kh6ng phg thuQc vdo gi6 trf cfia diQn trd rOto.
crta DCKDB didn
hinh
ca
KDB - DtEu KHTEN r6c
o6
oONo
ca
LzL
KDB
Hinh 4.2 bidu di6n quan hQ t6'c d0 - mdmen vd t6'c dQ - dbng cria
didn hinh.
Th6ng thudng, vdi phAn 16r- cdc loai tii, didm ldm viQp cfia tlQng co
6n dinhkhi 0 < s (s- vi kh6ngdn dinh khi s >s-.8 vfy, doan d{c
hfft,h
.o trong khoring s ) sn thudng goi ld doan d{c tinh kh6ng dn tllnh
eilu dQng co. Ndu diQn trd r6tt cfia dQng co c6 96, tri nh6, srJ thay tldi
'fdc dE dQng co trong khoing kh6ng t6i ddn dinh mf'c chi cd vii phdn
ir[m t6'c d0 tlinh mri'c. DQng co c6 thd ldm viQc qud tdi trong thdi gian
trgdn vdi m6men nh6 hon M** (mlmen tdi han). NOu m6men tdi vrrot
qud m6men tdi han, dQng co s6 mdt ddng bO vd dirng lai, khi tl6, thidt bi
bilo v6 dQng co phAi tdm viec dd cdt clEng co ra kh6i ngudn cung cdp,
trdnh phrit n6ng qud mrlc gAy hrr hai dQng co.
2- Gidn d.6 a6cto
Gi6n dd v6cto cfia m4ch
trrong drrong hinh 4.1b cho
tr€n hinh 4.3. Dbng trl hria
1,,, drrdc ldy ldm chudn vd sri'c
diQn dQng stator, E, sdm pha
00o so vdi I^. Ddng r6to .I2
c0ng chinh ld thdnh phdn
l,ao ra m6men dQng co vd
chfm pha mQt g6c @2 so vdi
E. Ddng stator f1 ld tdng
v6cto cfia dbng trl }r6a I^ vd
dbng r6to fr. frf thdng khe
I.o
Hinh 4.3: Gid.n d6 udcto mqch tuong
duong m1t pha crtq. DC KDB
hd kh6ng khf O cing pha vdi
dbng tr] }r6a I^ vd c6 bi6n dQ
tl lQ vdi dbng tt h6a ndy khi kh6ng
tinh ddn su bao hba.
Dbng 11, I'2 vd, I^ t1o ra cdc sri'c tr] dQng tudng r1'ng d stator, r6to vA
khe hd kh6ng khi (srfc tr} dQng h6 cdm). Trrong tq, O ti6u bidu cho tr]
thdng khe hd kh6ng khi (tt thdng h6 cim). Tdng qurit, m6men dQng co
sinh ra c6 khuynh hrrdng k6o tt thdng khe hd kh6ng khi vd sri'c til dQng
cria cuQn ddy tl6ng truc vdi nhau. V{y, mdmen do ilQng co sinh ra tl lQ
vdi tich cfia bi6n d0 tir th6ng khe hd khOng khf vd srlc tr] clQng cuQn d6y
(stator hodc r6to) vi sin cld'a g6e l6ch pha gif,a chring, nghla ld:
lfa
c6,: 6z
thay gid tri ndy vio cdng thrlc tren, ta suy ra:
fufr = K@. 12.cos@2
= n/2 -
tD2,
3. DCKDB r6ta,l6ng *6e
DCKDB rdto ldng s6c drtoc dilng rdt r6ng rdi trong nhi6u rtng
cOng nghiQp. Blng cdch lua chon cdc inidt tg kh6c nhau dd thay
diQn trd vi diQn khring r6to, kdt hop vdi cdc mtc dQ khdc nhau cfia
rfurg r6nh sdu ho{c ldng s6c k6p, c6 thd thidt kd cdc loai DCKDB c6
tinh phi hop vdi cric rlng dung cdng nghiQp da dang. DCKDB cd
thtrdng tlrrgc chd tao phri hop vdi tirng rtng dung cu thd. Vdi cOng sudt
vUa vd nh6 - dudi 150kW - dQng co ldng s6c thUdng drroc chd tao
mQt sd loai quy chudn nhdt dinh. Tu) theo ti6u chudn ri6ng cria
m6i qudc gia c6 quy chudn kh:ic nhau cho DCKDB. Ngudi thidt kethdng s6 chon loai dQng co cd tl{c tfnh gAn vdi y6u cdu cfia minh nhdt.
Ti6u chudn NEMA cfia M! phdn loai DCKDB thinh 5 ldp: A, B,
D vi F. Hinh 4.4 cho thdy d{c tinh cd ti6u bidu cria cdc DCKDB th
c:ic ldp khdc nhau.
(%.ou)
c)
100
i:.
=g
I
)esign
E
lt
5% slip
\
,
,t
60
,,
la
a.
8,,
40
I
A
t
t
tr"
I
l'
.,
20
\l
1l
t
0
50
\
\
\
100 150 200 250
M(%Md,)
300
Hinh 4.{: DQc tinh co tiOu bidu ?ila cdc loai DCKDB
rdto l6ng s6c khdc nhau
DCKDB ldp A c6 tliQn trd vA diQn khring r6to nh6, do d6 c6 d0
dinh mrlc th,dp (2 - 4Vo), hiQu sudt vd hQ sd c6ng sudt cao. DQng co
I,ONG
co
KDB - DtEu KHTEN r6c
oO oONa co
KDB
723
thdng didu chinh tdc d0 ding bi6-n tAn ngu6n dp, dQng co ldp A t6
lrr thich hop nhdt ndu kh6ng c6 cilc y6u cdu dac biet khric.
r'rlc hQ
DCKDB ldp B cfing c6 d0 trudt dinh mri'c thdp vd m6men khdi alOng
lnrng binh. Tuy nhi6n, ddng khdi d0ng cria dQng co loai ndy chi blng 70
80Vo d6ng co ldp A cing c6ng sudt, do tlqng cd dudc thidt kd vdi rdto
lrlnh sAu ho{c l6ng s6c k6p dd diQn kh:ing rdto khd cao nhXm gi6m ddng
hhdi dQng nhung ct5 dign trd khdi ddng cao dd duy tri mdmen khdi tl6ng
kh6ng nh6 hon d6ng co ldp A.
DCKDB ldp C sfi dung r6to ldng s6c k6p vdi diQn trd r6to ldn hon
rlQng co ldp B. DQng co loai ndy c6 m6men khdi dQng cao (cd 2,5 ldn
M,t,) vd. ddng khdi dQng thdp hon dQng co ldp B. Tuy nhi6n, so vdi dQng
r:<t ldp B, dQng co ldp C c6 m6men cuc dai thdp (cd 2 Ma), hiQu sudt
th0p hon vd d0 tnrot dinh mf'c cao hon.
DCKDB ldp D ding r6to ldng s6c don vdi diQn trd r6to cao vd diQn
khdi dQng cao (cd 3ldn M6),
vr\ ddng khdi dQng thdp. Tuy nhi6n, dQng co c6 dQ truot dinh mri'c cao
6,50Vo) vd hiQu sudt thdp.
DCKDB ldp F c6 d{c tinh co cfng (d0 truot tlfnh mr?c cd 2-4Vo) vir
rldng khdi dQng thdp. Tuy nhi6n, tlQng co c6 m6men cuc dai vd m6men
khdi tlOng thdp.
khd,ng r6to thdp. Do d6, dQng co c6 m6men
4- DCKDB r6to d.dy qudn
IJu didm quan trgng cta DCKDB r6to dAy qudn ld c6 thd th6m diQn
trd vdo mach rdto d6 ddng, do d6 dQng co thrrdng drroc chd tao vdi diQn
trd r6to thdp tld tdng hiQu sudt khi ldm vi6c. Khi khdi tlQng, diQn trd
phu cd thd drroc th6m' vdo tlQng co dd tdng m6men khdi dQng ddn mrlc
y6u cdu. Ngodi ra, cfing c6 thd dua ngudn diQn rip vio r6to dd tlidu khidn
tdc d0 dQng co.
Hinh 4.5 bidu di6n quan hQ t6'c tlQ - m6men vd tdc d0 - dbng diQn
ctia DCKDB rdto dAy qudn khi thay ddi diQn trd phu th6m vdo m4ch
rdto.
Tuy nhi6n, dQng co loai niy c6 nhidu khuydt tlidm so vdi dQng co
ldng s6c: giri thdnh cao hdn, cdn b6o dudng chdi than vd vdnh truot, kh6
sfi dung 6 mdi trrrdng khdc nghiQt hodc d6 chdy nd... Do d6, dQng co loai
nhy kh6ng th6ng dung nhu dQng co l6ng s6c.
trd phrJ
vd c6ng t5c to
GiAm di€n trd phq
oonglu rni
A., vA
A, md
I
D6ng A'
l.
D6ng A,
Hinh 4'5: EQc tinh
x:,y"i:r':7_":;r:":::r::;",::
qudn hhi thav
4.2 KHit oQnc vA nAwr oQr,rc cd rnoruc odr,rc s0
4.2.1Khtti dQng
Khi khdi rl6ng DCKDB brng cdch n6'i trrrc ti€p d6ng co vao l
ddng khdi dQng cao cfia d6ng co c6 thd 6nh hudng tldn lrrCi
diOn vd
thidt bi stl dung chung ludi di6n nay. Do d6, thudng phai tfnh d6n
phrrong ph6p girim dbng khdi d6ng khi sfi dung DCKDB.
Ddi vdi DCKDB r6to ddy qudn nhu d6 crip d tr6n, c6 thd
thOm
trd vdo r6to dd gidm ddng khdi dQng va tdng m6men khdi dQng.
Ddi v
cd d6ng co r6to ldng s6c vd ddy qudn, c6 thd sfr dung phrrong
phdp giA
cli6n rip stator, thay ddi tdn s6'cung cdp cho stator hodc
thay ddi
khdng stator. Vdi tlOng co r6to dAy qudn, cbn c6 thd sir
dung phr
co
KDB - DtEu KHTEN
rdc oo o)rvo ca
KDB
Phuong phdp th6ng dUng dd khdi dQng DCKDB r6to ldng s6c ld
dp stator bbng crich ddi ndi Y-A, hodc ding biSn rip t\r ng6u. Vdi
phdp khdi dQng Y-A, clQng co tldu A khi hoat clQng binh thrrdng.
khEi dQng, stator duoc ddu Y, cho ph6p gidm dbng khdi dQng
ng 3 ldn, nhung ddng thdi m6men khdi dQng cfing gidm tli cd 3 ldn.
I phuong phdp khdi dQng dDng bidn rip trt ngAu, ndu goi ti s6'gita
thrl edp vd so cdp bidn :ip ld a1, ddng vd m6men khdi dQng cria
l0rrg co gi6m di a72 ldn. Ngoii ra, do qurin tinh diQn til kh:i ldn cfia r6to,
ry ddi ndi trl mach khdi dQng sang mach hoat dQng binh thudng c6 thd
fly ra cdc xung dbng qud dQ rdt cao.
1,1,2 Cdc
chd d0 ham
C[ng gidng nhrr tlQng co DC, cdc chd tlQ hem ctia DCKDB c6 thd
fltlu ra thdnh:
1- Hdm trii sinh
2- Hdrn ngugc
3- Hdm dQng n5.ng
Ddi vd'i chd d0 h6m tlQng ndng, c6 mQt so'cdu hinh khdc nhau dd
thyc hien. Trong phAn ndy, chi khAo sdt h6m dQng nlng kich til tlQc lQp
lA cau hinh drroc sfi dgng rQng rii nhdt.
(Phdn hdm tdi sinh vd hdm ngrroc xin tham kh6o trong c6c gi6o
lrlrrh Ky thu{t diQn hoac M6y alien)
(Xem
vi du 4.1)
Hdm dQng nd.ng hich ttl ilQc lQp
Hdm tlQng ning dtroc srl dung cho edc hO truydn rlOng kh6ng tlAo
chi6u.
kich tt tlQc lfp, tlQng co drrgc cdt ra kh6i ngudn
roay chidu ba pha vi drrgc n61vdi ngudn DC. Cdc cdch ddu ndi ngudn DC
Vdi tl6ng co trinh bhy tr6n hinh 4.6.A,8. Cdu hinh (c) va (f) cho ddng
chqy trong c6c pha cfia d6y qudn stator ld nhtr nhau, tuy nhi6n albi h6i
tldi ndi m4ch phrlc tap. Cdc cdu hinh (a), (b), (d) vd (e) thtrdng drroc s&
dqrng hon do kdt ndi don gidn.
Dbng mQt chidu chay trong stator s6 tao ra tit tnldng tinh (drlng
yOn). Dbng r6to cdm dng s6 sinh ra m6men hdm ditng rdto mQt cdch
rrharih ch6ng. M6men hdm vd thdi gian hdm c6 thd tlrroc di6u khidn bdi
Khi hdm
clQng ndng
BQ
chlnh lrru
Htnh 4.6.* Kdt ndi DCKDB dd th@ hian hdm dQng nd,ng
'v3
1t2
Hinh 4.68.: Cdc so dd ddu ngu6n DC khi hdm dQng nang hich
d|c lfup DCKDB
til
Mach hJdng drrong cria dQng co 6 chd dQ hiim dQng ndng kich trf dQc
l{p suy ra til mach htdng drrong & chd tlQ tlinh mrlc (tdn sd g6c ol vA tdo,
t10 tldng b0 ld cqda) nhrr trinh biy drrdi d6y:
olr'to co xoa - oEu xutEtt rdc oQ D2NG co KDB
- M4ch tudng duong cria
t27
6 tAn sd co, hinh 4.7a, dugc suy ra
tU mqch trrong duong cria dQng co d tdn sd o. Tdc t10 tl6ng bO cria dQng co
d tAn sd orr
li
dQng co
roaor.
- Chia cdc d4i lrrgng trong m4ch hinh 4.7a c}l.o (Wu/roa;), ta
mqch nhu
tlrrgc
hinh 4.7b.
- Lrru f 1d d chd d0 hem tlQng ndng kich til dQc l{p, a}r = 0 vd 111461 - 0,
thay'cdc gi6 tri niy vio m4ch hinh 4.7b ta drroc mach trtong drrong cfia
kh6ng tldne b0 trong chd d0 hdm dQng ndng tr6n hinh 4.7c.
COG
"o
Ddu trrl trong thinh phdn [-R'zl(l - s)] chi mOmen hic niy ld 6m vA
tlQng co nhfn ndng lrrgng co ttd bidn thinh ndng luong diQn. Khi da lft
/ lA mOmen c6 chidu ngugc lai so vdi chd clQ dQng cd, s6 kh6ng cdn kd
ddn ddu trt niy trong mach trJong tlrrong. MQt htu f khdc lA khi thay
olrbr = 0 vAo mach hinh 4.7b, sE nhdn drroc d phdn phia tr6i dudng tillt
n6t AB mQt ngudn v6 cing ldn ndi tidp vdi mQt diQn trd v6 cing ldn.
PhAn mqch niy, do d6, c6 thd thay blng mQt ngudn ddng lar. Bdt ky
[dng tr& ndo ndi tidp vdi ngudn dbng tldu kh6ng 6nh hrrdng tldn gid tri
c0a ngudn dbng, vA do d6 c6 thd b6 qua nhrr Xr. Tuy nhi6n, Rr c6 thd
ttugc gifr lai nhu tr6n hinh 4.7c ndu mudn tinh ddn tdn hao tr6n diQn trd
ddy qudn stator.
ffix,
#*,
-Ri
1-s
Ri'.o
odbl-o
rB
b)
Hlnh 4.7: So d6 tudng duong crta DC KDB d chd dQ
hdm d6ng ndng h,i.ch td dQc lQp
Gid tri cria ngudn ddng d8ng tri 16l drtoc suy ra tt dbng mQt chidu
cung cdp cho dQng co d chd d6 hdm vd so ad adu n6'i ngu6n mdt
vdo dQng co. Ngudn ddng.I6l dugc xem ld ngudn ddng AC, c6 gi6 tri
cho khi chay qua d6y qudn ba pha stator s6 sinh ra srlc til tlQng (
c6 ctng bi6n d0 nhu srlc trl clQng sinh ra bdi ddng 12.
B6ng
drJd'i
ddy cho quan hQ grfta l61vd.I7 theo cdc so dd trOn hinh 4.6.
Dbng 161 trong mach hinh 4.7c duoc phAn chia gifra tdng trd n
r6to vd di6n khdng tr} h6a X*. Vdi nhfrng gi6 tri nh6 cria (1 - s), n
ld tdc dQ thdp, dbng rdto c6 gi6 tri nh6. Vi v4y, ddng trl h6a s6 .c6 gi|
gdn blng,Ial. Lttu f ld trong thrrc t6, thrldng ding .I4, vd trrong rlng ld
c6 gi6 tri cao dd ham nhanh. Do d6, vdi cdc giri tri nh6 cria (1 - s),
tri cfia I^ c6 thd dfi ldn dd mach tir cria d6ng co lAm viQc d doan b6o
Khi d6, mach trl cfia tlQng co ld phi tuydn vd girl tri cfia X," s6 bidn
phu thudc vio giri tri cfia dbng trl }n6a I^.
PhAn tich str hoat tlQng cria dQng co 6 ch6 d6 h6m ddng nf,ng
tinh tdi su phi tuydn ctia ddc tinh trl h6a c6 thd tidn hdnh nhrr sau.
Tr) m4ch trrong duong hinh 4.7c:
f,
I2*x2^=trz
_
ltll
\2
I
+(xr+x^)21
L[r_sJ
E=X^I^
r,
J
(4.
Thay (4.27) vAo (4.26), kdt hop vdi (4.25), suy ra:
'
I'r=T*
x^
@
oQuo cd xoa -
oAu xnEx r6c
N
oQxe cd KDB
L29
M6men hdm tfnh bdi c6ng thrlc:
3 .Lr.&
M= roat
- l-s
(4.30)
Mdmen hdm thrrc tr6n truc dQng co bao gdm th6m m6men ma sd.t,
tdn hao do qu4t gi6.
Dd tinh ddc tinh co cria dQng co d chd tlQ h6m, c6 x6t tdi 6nh hudng
cria su phi tuydn cfia d{c tuydn tr} h6a cria tlQng cd, vA trdnh gi6i cdc
phuong trinh phi tuydn phfc tap, thrrdng lim theo trinh trr sau:
- Cho trrrdc mQt gi6 tri I^, suy ra gid
tri E tuong rftrg theo d{c tinh
E = f(I)
- Tinh
X- tit c6ng thric: X^ = !
rm
crlc
Sm=
1-
(4.32)
'E'
(Xr+X^)
M6men hdm crrc dai:
M*- = 2aat
,'4'*2
=t (Xr+X^)
,
(4.33)
V{y, theo (4.33), m6men h6m crlc d4i M* dQc lQp vdi R2. Trong
ving tuydn tinh cfia tl{c tinh trl h6a, tai mQt gi6 tr! cho tnrdc cria tdc d0,
m6men tt lQ vdi 122 . V6i tdc dQ thdp; nghia ld (1 - s)'nh6, s{ tl lQ cria
130
N€u sfi dqng DCKDB r6to ddy qudn, c6 thd th6m di6n trd phg
r6to tld c6i thiQn d{c tinh him d t6'c d0 cao. Khi cdn h6m nhanh,
ctia diQn trd phu c6 thd chon sao cho m6men hdm dat gi6 tri crr. c
tdc d0 cao. Khi tdc d0 gidm di, diQn trd phu drroc cdt bCt kh6i
duy tri mOmen hdm cao.
D{c tinh co cfia dQng co d chd tlQ hdm dQng ndng kfch tU dQc
trinh bAy tr6n hinh 4.8. (Xem vi dU 5.2).
t I*'
R'rr t R'r,
Ioo
t ",,
Hinh 4.8: DQc tinh co DCI(EB 6 chd
dQ hd;m ddng ndng
rdt higu qui dd hdne dirng DCKDB
thudng tlugc srl dung trong ttrgc td. Vi phrrong phdp hdm nAy ti6u
cOng sudt it hdn nhidu so vdi phrrcrng phdp him ngrrgc, n6n hAm
ndng kich tU dQc'l{p cfrng clugc srl dUng dd hdm ha tei thdntrng, vi
trong cdc hQ thdng tdi k6o cfia m6.
Phrrong phdp hdm dQng niing
4.3 DtEu KHIEN ro'c s0 sOnc cd KHONG sdnc s0
Trong c6c mgc dudi dAy s6 ldn ludt gidi thiQu c6c phrrong phdp
b6n tld didu khidn tdc d0 DCKDB dtng bdn ddd c6ng sudt. Cdc
phdp ndy bao gdm:
1- Didu khidn diQn rlp stator
2- Didu khidn tdn s6'
3- Didu khidn diQn trd r6to
4- Di6u khidn c6ng sudt
trudt r6to
rt
rI
I
ttt,)Nc
co
KDB - DtEu KHTEN roc oQ D)NG CO KDB
4 4 DtEu KHTEN
131
srEn Ap sTAToR
N6u gii thidt dicn zip ba pha dat l6n d6ng co la hinh sin, dac ti'h
.,/ r:tia d6'g co kh6ng ddng b6 khi thay doi bi6n d6 di6n rip stator (girl
rrllrryen tdn sd), c6 dang nhu trinh bdy tr6' hinh 4.g. L,ru y la toc
dd fng
vrti M,,,,., cda d6ng co kh6ng ddi (c6ng thfc (4.21)), tuy nhi6n giri
tri cria
,4/,,,,,, gidm ti 16 voi binh phrrong cria di6 n dp stator (cdng
thf.c (4.2D).
Ile th6'g ndy thrrd''g dirng voi rai ld bom hoac quat gi6 vd sLi du'g
'l.rr!{ co loai c6 dQ trtrot dinh mrlc cao (s7,n cd 0,1 + 0,2) nhrr d6ng co ld.p D.
vi6c thay ddi di6n dp stator thrrdng
rlr,,rr dp xoay chi6u nhLr
Ilinh
trinh bdv
duo-c
thuc hi6n bdi b6 bicn d6i
drrdi dAv.
khi di|u chinh d.iAn d,p stetor
l- Mg.ch didu hhidn diQn dp stator
so dd nguyon lyi mach didu khidn di6n rip stator st dung bQ bidn ddi
tltr,'rt eip xoay chidu ba pha trinh bdy tr6n hinh 4.10. v(ii dQng co c6ng
nr{ib nh6, m6i cip scR song song ngudc c6 thd thay bdi triac. so d6
cl
lri t,hd sir dung vdi tl6ng co ddu sao (y) hay tam giric (A), so dd Cz chi sfi
rh,rrg vdi d6'g co tldu A. vdi so dd c2, ddng hdi bdc 3 tdn tai trong
cu6n
rltiv ddng co, gdy tdn hao phu tr6n d6ng co. (chi tidt v6 hoat d6ng cua
bd
fririir ddi DAXC ba pha xin tham kh6o th6m trong c6.c gi6o trinh Di6n tfi
4.9: Dec t{nlt DCKEB
r32
Hinh 4.70: Mgch didu khidn diQn dp ba pha
Vdi so dd Cl, g6c kich cr tinh tir thdi didm 6p pha (uf dqr; Ve1r)
zero. Vdi sd dd Cz, g6c kich cr tinh tU thdi didm 6p ddy (ui dq; Yrs)
zeto.
G6c
kich tdi han cria mach hinh 4.10 tinh bdi c6ng thfc:
q1, = fgn-l
b
Kio
trong d6 .R;n + iXi, lh tdng trd vdo cria DCKDB'
Vdi g6c kich a s ath, dien dp tl{t l6n ttQng cd kh6ng ddi vd
diQn 6p lrrdi (b6 qua sgt dp tr6n linh ki€n), dbng qua clQng co IA li
Dbng vd 6p tr6n dQng co l6c ndy c6 dang sin' Vdi d 2 atn, ddng qua
co ld gi6n do4n vd dp tl4t l6n dQng cd giem khi ct tdng' DiQn dp d4'
dQng co blng zero khi g6c kich a tudng fng vdi sd tld Cr vd Cz ldn
la 15oq vd 180o. Vi dd didu khidn tlugc diQn 6p dOng cd, dbng
phdi 6 chd clo gidn doan, hdn nfla, tdng tr6 mech tlQng co bidn
theo clQ tnrqt s, non viQc gi6i tich hQ thdng BBDD AXC - DCKDB
phf,c t4p vi d{c tinh co hlc niy s6 kh6c nhidu so vdi khi gia thidt
dp stator ld hinh sin nhrt hidh 4.9.
Mq,ch dQng tqc nhrr hinh 4.10 cht cho ph6p dQng co ldm viQc
d0 dong co (phfo tu I) va chd tlo hdm ngrldc (phdn tu IV). Mech
4.11 cho ph6p dQng co ldm viQc I 4 g6c phdn trr'
Trong niach hinh 4.11a, cfic cf;p thyristor A, B vi C cho
thdng ldm viQc d phdn tu I vd IV, khi d6 d{c tinh co ctla h0
mOt gid tri diQn dp ra-pdo d6 v6 tr6n hinh 4'12 blng drrdng n6t
oQua
ca xoe - o6u xurEN rdc
& oQNa co KDB
133
b)
Hinh 4.77: So d6 didu khidn dipn dp stator DCKEB hogt dQng
d cd bdn g6c phdn tu
Hinh 4.72: DQc t{.nh co crta
hinh 4.11
Cdn lrnr f, trong mach hinh 4.!la, khi d6o pha - nghia ld chuyin tU
bQ thyristor ABC sang bQ thyristor A'BC'vA ngrrgc l4i - cAn ddm b6o b0
0hyristor mdi chi drroc kich d6n khi bQ thyristor cii dd t{t hoan toin dd
trdnh ng{n maeh cdc pha.
Khi di6u khidn tdc d0 kidu vdng kin, so dd vdi hai vbng hdi tidp
(vbng tdc d0 vd vbng ddng diQn), gi6'ng nhu tlidu khidn vdng kin dQng co
DC trinh bny d chrrong 3, dugc sfi dgng. So tl6 khdi he thdng ndy trinh
bAy tr6n hinh 4.13a cho hQ thdng hoat dQng d mQt g6c phdn tu vd hinh
{,t3b cho hQ thdng hoqt tlQng d bdn g6c phdn trr.
hQ t!.dng
Vdi so dd hinh 4.13b, khi t6'c d0 d4t d6o chidu, sai sd tdc tlo lfc nAy
tE d6o chidu vA vugt qud mfc gidi han dn dinh trrrdc. Khi d6, b0 didu
hhidn tlAo chi6u s6 ngdt xung kfch ddn cdc thyristor ldm cho dbng diQn
tao ra nhhm ddm b6o c:ic thyristor tdt hodn toAn. Sau d6, b0
mdi sE nh{n xung kich dd didu khidn tlQng co quay theo chidu ngrrgc
Lric ddu, tlQng co s6'ho4t dOng d chd tlE hdm ngrroc vA giAm tdc vd
sau d6 ting tdc theo chi6u ngrroc lai.
(PI)
Khdu hi0u chlnh
vOng idc
OO
Iy:
Khau beo hda
T-'-'llll
Mach krch
M6y phdt tdc
a)
Kheu
hieu.linh
vong roc 00
xnau oau no,
$il lit',T[l
Mach krch
b)
MAy phet tdc
Hinh 4.73: Didu khidn tdc dQ ubng kdn DCKDB dilng bQ bidn ddi diQn
xoay chidu ba pha
tu
b) HQ thdng hoqt d6ng 0 bdn g6c phdn tu
2- Tvuydn d.Qng bom ho(rc qugt gi6
Truydn dQng cho bom ho{c quat gi6, dd thay adi trlr luong cfia
chdt blng cdch thay adi tdc d0 dQng cd, la tlng dgng chinh ctia hQ BB
A)(C - DCKDB. Phdn drrdi dAy sE khAo s6t hQ thdng vdi t6i logi nhy.
Vdi tei bom ho{c qu4t 916, m6men tei fi le thu{n vdi binh ph
crla t6'c d0, vA c6ng sudt - vdi lflp phrrong cfra tdc d0. Lrtu lrrong cria
a) HP thdng
hoqt
dQng & mQt g6c phdn
tx)NG
co
KDB - DtEu KHEN
rdc
oQ oQna
ca
135
KDB
tldn bidn thi6n ld'n v6 lrru hrgng, ui du: khi t6'c dd gi6m cbn
hll'Z, dinh mrlc thi lur lrrong gidm cdn 1/8 dinh mfc, ndu gi6 thidt lrru
lrt,.rrrg dinh mri'c ritng v6i t6c d0 dinh mrlc. Do d6, hdu hdt cric hQ thdng
lrrrrrr vd quqt, ndu cdn tlidu chinh tdc tlQ, s6 c6 ddi tlidu chinh nh6.
M6men tAi quat gi6 hodc bom c6 thd vidt drrdi dang:
rfg so ddn
M" = C. af = C (1
lrorrg d6 C ln hXng sd
(4.34)
- s)2 o+tu2
M6men dQng co, M, cho bdi c6ng thrlc (4.17), ndu b6 qua ma srit vh
Inrr hao quat gi6 tr6n truc dgng co, c6 thd vidt:
M=M"
TrI dAy, suy ra: I'2 =
lrtrrrg
d6:
K
T
(t
|
-9.J"--.1
(4.35)
lJ*,1
I
(4.36)
K-
Ndu b6 qua ddng tr} h6a, c6 thd xem gd.n dring: /7
vr\o dQng co
= /2, khi
cl6 dbng
tinh bdi c6ng thrl'c (4.33):
(4.37)
C6ng thrlc (4.35) cho thdy vdi mQt gi:i tri cria dQ trudt s, ddng clQng
co ti 16 nghich vdi cln b4c hai cria diQn trd r6to R'2. Goi ddng dinh mrl'c
vr\ d6 trrrot dinh mrlc cfia dQng co ldn ludt la 165 vir s,1,,,, ttl (4.35) ta c6:
lo^ =
K
f.
-l
l(t-sa-l-l/so-
|
^lR'
(4.38)
|
I
T'I (4.35) va (a.36)isuy ra:
rL _
Ia^ Ttbidu thrlc (4.37)
c6
(r-u)G
(4.3e)
(r-su-).fi-
thd tim drroc Ir dat
cr,Ic
dai, I^o*,t4i dQ tnrdt:
(4.4o)
va
(4.41)
Bidu thrlc (4.41) cho thdy gi6 tr! I* > 16^vA' gi6m di khi vdi
cd c6 dO trrrgt tlinh mfc cao. Yi dry, c6 thd tinh ra tlugc khi d0 trugt
mrlc thay ddi tU 0,1 ddn o,2, tt' sd I."* 116* thay ddi tuong
1,35+1,05. Tuy nhi6n, hiQu sudt dQng co, vd trrong rtng In hiQu
thOng, s6 gi6m khi d0 trrrot tlinh mrlc tdng.
iidu thrlc (4.39), ngoiri ra, cflng chl ra rlng ndu tlQng co c6
sudt tlinh mrl'c bhng cdng sudt tldy tai, s6 bi qu6 dbng khi t6'c d0
giAm nh6 hon dinh mrl'c. Do d6, ndu tlQng co cdn ho4t dQng ddi
tdc d0 drr6i diuh mrlc, thudng phai chon c6ng sudt dgng cd cao hdn
sudt dlnh mrlc c0a tAi.
4.s DrCu KHTEN rAr'r sd
rAn ncudn AP
DONG Gd KH0NG
sdnc s0 vdl s0
Tdc tlo tldng bo cria DCKDB tl lC trrrc tidp vdi tdn sd ngudn
cdp. Do d.6, thay tldi tdn sd cung cdp cho dQng co s6 thay tldi tdc t10
bQ, vd tudng rlng ld t6'c dQ, cfia dQng co.
sri,c diQn tlong c6m fng trong stator, E, tl lc vd'i tich cfia tdn sd
cdp vd tu th6ng trong khe hd kh6ng l<hi (airgap fiur). Ndu b6 qua
rip roi tr6n diQn trd stator, c6 thd xem sfc di€n dQng E = diQn 6p
cung cdp. Ndu giAm tdn sd ngud.n nhung gifr nguy6n diQn dp s6 din
viQc gia tdng til th6ng trong khe h6 khdng khi. DQng co thrdng
thidt kd ldm viQc dinh mrlc t4i "tlidm c6nh ch6" (knee'point) cfja
tuydn tU h6a, nen sqt tdng tir thong sE dan cldn bao hda m4ch tU'
niy khidn dbng til h6a tdng, m6o d4ng dbng vd dp cung cdp, gia
tdn hao I6i vd tdn hao ddng stator va gey tidng dn co tdn sd cao.
lai, tt th6ng khe h6 kh6ng khi gi6m drrdi tlinh mrlc s6 lam giam
ndng t6i cfia dQng co. vi vay, viec giam tdn sd dQng co drrdi tdn sd
mrxc thrrdng di tl6i vdi viQc gi6m ttiQn 6p pha V sao cho tt th6ng
khe hd khdng khi drrgc giil khong ddi. Khi dQng co ldm viQc vdi tdn sd
cdp l6n hon dinh mfc, thrldng gifi atiQn 6p cung cdp khdng ddi va Ulng
mfc, do grdi hen cria cdch tliQn stator hof;c cfra tlien 6p ngudn'
Trong phdn giAi tich kd tidP, goi:
o=
i-
I tlm
DONG
ca
KDB - DtEu KHTEN
rdc
N
{.6.1 Ho4t dong vdi tdn sd audi
oQr,to
co
KDB
dilL mfc
r37
(a < 1)
Nhrr tla n6i d tr6n, thrrdng dQng co duoc di6u khidn hoat dQng vdi til
thdng kh6ng ddi. Til th6ng dQng co ld kh6ng ddi ndu dbng tU h6a duoc
girr cd dinh vdi moi didm lirm viQc. Theo hinh 4.1b, tai didm ldm viec
dinh mrlc:
, = Ed^ 1
t^
fd^ 2.n.Ih
trong d6 Z- lA tliQn 6m mqch tt h6a. Tai tdn sd ldm vigc f,
E1
I^-
(4.43)
(4.44)
a'fa^ 2.n.L^
Tir (4.43) vd (4.44) suy ra didu kiQn dd ddng I- kh6ng tldi va bXng
(4.45)
E = a.Ea^
dinh mrlc:
Cdng thri'c (4.45) cho thdy til th6ng d6ng co drroc gif kh6ng ddi ndu
Ll lC @lfi duoc gifr khdng ddi (E /f = cosnt).
Tuy nhi6n, trong thrlc td, viQc giil tt thdng dQng co khdng ddi dbi h6i
mach tlidu khidn phrlc tap. NCu b6 qua sut rip tr6n diQn trd vh diQn khdng
tAn stator, c6 thd coi E = V. Khi d6, nguy6n tic didu khidn E / f = const
drroc thay bhng V /f = corSt.
Phtong phdp til th6ng hh6ng ddi (E lf = const)
Gia thidt dQng co ho4t dQng vdi tdn sd f, trl m4ch tuong drrong hinh
4.lb, suy ra:
(4.46)
I'z =
;
d6:
L,ru
"
-
a'@db
-o
G.47)
s'adb
f lA rqaa ld tdc tlO ddng bQ trrong
rlng vdi tdn sd tlinh mrfc.
M6men diQn tU cria dQng co:
(4.48)
Vdi mQt tdn s6'f cho trrrdc, theo phuong ph:ip trl thdng kh6ng
drroc gifr kh6ng ddi. C6ng sudt dign tU cria dQng co dat crtc dai tai
trudt sn md d d6:
oxr=142
-sndh hay ,^=x4l=,
Thay vdo bidu thfc (4.48), ta c6 m6men cuc dai cria dQng co ld:
M^=r+
- 2aaa %
X2
trong tl6: ddu + ri'ng vdi chd d0 dQng co; ddu - rltrg vdi chd d0 m:iy
Bidu thrt'c (4.50) cho thdy khi thay ddi tdn sd theo phrrong phrip
th6ng kh6ng ddi, mdmen crrc dai M,* cl0,a dQng co girl kh6ng adi vOi
tdn s6'ldm viQc, cA trong chd dQ dQng co l6n ch6'd0 ham trii sinh.
Ngodi ra, cdc c6ng thrlc (4.46) vA (4.48) cho thdy rhng vdi mQt gi
tri cd ttinh cria (sa), ddng fito 12 vA mdmen M ld hXng sd dir tdn
thay ildi. C6 thd chring minh drroc li g6c l6ch pha g;tta E vA dbng
12 ciung kh6ng ddi vdi cilng m6t gid tri cria (so). TrI ddy, c6 thd suy
rlng vdi cing mQt gi6 tri cria (sa), dbng stator cfing gitr nguy6n. T6m la
khi tt thdng ud. (sa) duqc git kh6ng ddi, ctic gid tri cia m6men d6ng
M, ddng stator
11 ud
Ta kh6o srit
j
ddng r6to
I"
cfing kh6ng ddi.
nghia ctia dai lugng (sa). Til c6ng thrlc (4.47):
a' aao - ao"l
-
(4.5t
(Daa = (Dat
Lrru f ld dai lugng er B9i li t6'c dQ trtrot (bidu thfc (4.51), ld sai
,o
lQch girla tdc clQ tr} trudng quay stator vd tdc dQ quay cria r6to, hay n6i
c6ch khdc, d6 ld d0 sut tdc cfia dQng co so vdi tdc d0 ddng b0 khi dQng
mang tdi. Theo c6ng thfc (4.5L), gid tri (sa) kh6ng ddi nghia ld dQng
hoat dQng vdi d0 sut tdc cd dinh.
Cdc phdn tich tr6n cho thdy ndu didu khidn dQng co theo phrrong
phdp tir thdng khdng ddi, vdi cing mQt giri tri cfia m6men dQng co, dQ
sut tdc cria dQng co so vdi t6'c d0 tl6ng b0 tudng tng (acu) sc khdng ddi
vdi moi tdn sd cung cdp. Til dAy, c6 thd suy ra df;c tinh co cria dQng co, vdi
cric tdn sd kh6c nhau, li "song song" vdi nhau trong kho6ng 0 < I ( s-.
D?ng didn hinh cdc d{c tinh co cria clQng cd trong trrrdng hop nAy bidu
o2NG
co
KDB - DtEu KHTEN
rdc D0
oQNo
co
KDB
139
M
Hinh 4.14: DQc tinh co DCKDB khi didu hhidn tdn sd cung cdp
a) Hoqt d6ng udi quy luQt
tt
th6ng khing ddi (E lf = const)
ludt V I f = const
TU c6ng thrlc (4.51) c6 thd suy ra ld gid tri (sa) kh6ng ddi cUng c6
nghia li tdn sd r6to kh6ng ddi:
b) Hoat d6ng udi quy
to= s.f f, = tr)r
,u^
f^= f^
vdi s < s-, thudng c6: (R'zls) >> (aX'z), do d6, tr] cric c6ng thtl'c (4.48) vd
(4.51) suy ra:
M
eo2
""d!1
= (.l.atRz
C0ng thrl'c (4.51) cho
nhrr mQt drrdng thEng.
(as)= (const) .c4t
th{y vdi s < s-, d{c tfnh co cria tlQng co gdn
Phdong phd.p Vlf = eonst
Trong phrrong phdp ndy, khi didu chinh tdn sd f, t7 s6 Vlf duqc gitt
kh6ng ddi vi thrrdng lA gitr blng ti s6'nAy d dinh mr1c. Cdn lft )t le khi
m6men tili tdng, ddng dQng cd teng lim gia tdng sut 6p tr6n cliQn trd
stator, d6n ddn E gi6m, c6 nghia ld tlr th6ng dQng co gi6m. Do d6, rlQng
co kh6ng hodn todn ldm viQc d chd dQ tt th6ng kh6ng ddi.
Dd tlon gi6n trong tinh todn, srl dung mach trrong duong clon gidn
h6a cria dQng co nhrr hinh 4.1d. Lrru f ld trong so dd nDry, til th6ng sE
duqc bidu thi gidn tidp qua E. Tt so dd trdn, suy ra d diQn :ip vd tdn sd
cung cdp Id tllnh mfc - V6a vd. f6* - ta c6:
3
M= (Dab
(4.52)
vd.:
-3 |
M^* =
2rat
';^
In, tGr, +{x,.xl1
1
d tdn sd f ndo d6, x:ic -dinh nhu c6ng thrlc (4.42),
t0'c tlQ ddng
diQn dp cung cAp vd diQn khring X trong mach tuong duong s6 c6 gid
ldn luot ld. ao46, aV6^ vd. aX. Thay c6c gi6 tri niy vdo c6ng thtc (4.
vd (4.53), ta drroc bidu thrl'c tinh m6men vd m6men cqc tlai cria dQng
tai tdn sd cung cdp f sE ld:
l6n, (Rr/a) << (Xr + X), do dd gid tr! cl ia M^* hdu
kh6ng ddi trong cd chd tlQ dQng co vA mdy phdt. Tuy nhi6n, v6i gi6
nh6 cria f, M^* s6 gi6m di d chd d0 d0ng co vd tdng l6n d chd d6
phdt. Di6u nAy duoc bidu di6n tr6n hinh 4.L4b.
Srr gi6m cisa M^o,6 tdn sd thdp dtroc gi6i thich li do 6 cdc tAn
ndy, sgt 6p tr6n di6n trd stator rlng vdi m6men tdi ld,n s6 d5n ddn vi
girim tl{ng kd giri tri cria E, vA tuong rl'ng ld tir th6ng dQng co. ViQc gi6m
tt th6ng, do d6, s6 d6n tldn srr suy gi6m c(ra M^* vd d0 crlng cria ddc
tinh co.
Dd bU lai srr suy gi6m ttr th6ng d tdn sd sd thdp, thrrdng chon quaq
l<hi
f
V = Vo + K.f
I
trong d6: Vo drtoc chon dd cung cdp tir th6ng dQng co lA dinh mrlc tai
f = O, vd K tlrrgc chon dd dat drroc gi6 tri cfia V lh, Va^ tai f = fo^.
hQ gifra V vd
/ld:
4.5.2Holt dQng vdi tdn sd tr6n dinh mrlc
(a >1)
Vdi tdn sd hoat dQng ldn hon tdn sd dinh mrlc, diQn dp cung cdp cho
dQng co girl kh6ng tldi va blng tlinh mrtc. Khi d6, dQng co lAm viQc I chd
dQ gidm trl thdng (field weakening).
Gid
(X1
+
X)
tri
cia M vd M^* tinh drroc blng eich thay thd
b6i a(Xt + X, ) trong c6ng thrlc (4.52) vA (4.b8):
olaa
bdi
acDa6
vA
co
KDB -
M_
ileu
3
adb
KHTEN
rdc
N oQua co KDB
w^*
{nr+L1}
s
L4r
(4.56)
,a)L
+a2(xr+X2)2
(4.57)
Vi a > 7, gi6 tri cria M-o' sE gi6m khi f tdng. D{c tinh dQng co khi
lAm viQc trong chd t10 girim til th6ng nhrr trinh bdy tr6n hinh 4.15.
a>1
I teng
i
Mr*
-Mr",
.Ilinh
Dr/dng gidi hqn
cong sudt khong ddi
4.15: Ddc
tinh DCKDB hoat dQng udi
bQ
bidn tdn (f > fa)
Milmcn vd e6ng sudt d6ng eo khi tdm viQc uti bidn td'n ngu6n d'p
Ydi c6c bQ bidn tdn, thrrdng ddng tliQn cho ph6p cgc dai tlrroc gidi
han I mQt trf sd nhdt tllnh ndo d6, dan ddn viQc m6men vA cong sudt ra
cfia hQ thdng truydn dOng bi g1di hqn I mqt mrlc cho ph6p hfcrng rng ndo tl6.
Phdn kh6o sdt tr6n cho thdy rhng khi tt th6ng tlQng co drroc gif,
khong ddi, vdi mQt gi6 tri cho trudc cria ddng stator, m6men dQng co vi
tdc dO trudt la kh6ng tldi vdi mgi tdn sd. Nhu v4y, vdi a 1 L, khi ho4t
dQng d chd d0 tt th6ng khdng ddi, m6men cho ph6p cria dQng co li hlng
sd vd ta n6i ttQng cd ho?t dQng trong vr)ng m6men kh6ng tldi. Khi hoat
cd hoat tlQng d chd d0 tir thdng kh6ng ddi, vd tudng rlng vdi ving
viQc mOmen kh6ng rldi nhu v6 tron hinh 4.16.
Ydi a >1, ta
c6:
".+l
+a2(x,+x)2
Vi s c6 gi6 tri khA nh6 n6n bidu thfc trdn c6 thd vidt l4i gdn dring ld:
,, _ sVd^ _ Va^ [ aoa6 - co )
, "--F;-El "',, )
hodc:
Tt
vi
(a.roau-ro)=
^=Wr"r;,
bidu thrl'c tr€n c6 thd thdy
trrong rlng ld
lt.t6c
rlng tai
mQt gi6
tri
cho trudc cria
truot <o"r tdng tuydn tinh vdi a.
cria s nh6, c6 thd xem .R, ls >> X2, do d6, .I2 gdn
ilQ
Vi giri tri
tring pha vdi E. Ndu b6 qua tdn hao r6to,
cdng sudt tl6ng co drJa
P"=3EIz
B6 qua sgt dp tr6n stator, E = V6* vd do d6:
P" = 3'Va*. Iz
I
I
L__
lt
/l
I
'\.--iM
osl /
ra
I
DlNG
co
KDB -
DEu
KHTEN
rcic oo oONe co
KDB
r43
Trl bidu thfc tr6n, ta thdy P,. li hing sd ri'ng v6i I', cho trudc, vd
tuong r1'ng ld 1r cho tnJdc. Hay n6i mQt ceich khdc, vd'i o >1, bQ bien tdn
lr\rn vi6c vdi di6n dp ra co' dinh s€ c6 c6ng sudt ra cho ph6p ld kh6ng
rltli. Ta ndi dQng cd hoat d6ng trong vilg c6ng suat kh6ng ddi. Lric udy,
n6'u ddng cung cdp dQng co dat mfc cuc dai cho ph6p, c6ng sudt ra ctia
dQng co clng dat mfc crJc dai cho ph6p nhuv6 tr6l hinh 4.16. Luu y ld
lhdmen cho ph6p ctia d6ug co girim khi tdc dQ tdng.
4.6 Dreu KHrdN rArrr sd DONG cO KHONc odrrrc e0 vdr s0
elEru
TAN NGUON DONG
DCKDB c6 th6 duoc cung cAp bing bidn trin ngu6n 6p hoac bi6n
ngu6n
ddng. Trong muc tr6n, hoat dQng cria dQug co vdi bidn tdn
ldn
n rip dA duoc khdo sd.t. Trong phdn udy, hoat ddng cria d6ng co vdi
bidn tdn ugu6u dbng se rluo-c phAn tich.
tich hog.t dQng cia d.Qng co iJ td.n sd dlnh mtc
Trong phAn ndy, rnath trJdng dLtong cua dQng co nhu hinh 4.1b
c 6p duug vo'i rrgu6u dbng 11 cung cdp cho stator ddng co thay cho
rip V. Ddug ngudn .I1 lfiOug phu thu6c vdo thdug sd dQng co vd
lQn :ip V thay dtii tuy theo tdng trd dQng co.
Theo hinh 4.1b, gi:i tri cria dbng 1,,, vd I', phu thu6c vdo tdng tro
trlng rnach nhrinh nAy. V6'i c6,c gi6 tri thap ctia dQ trudt s, t6ug tro
ch nhrinh r6to cao n6n dbng tit h6a /,,, sO cao, khi d6, dQrrg co sd hoat
rrg o ving bdo hda ctia mach til. \ vQy, khi tinh torin dac tinh co cua
B cung cdp bdi ngudn dbng, cdn thiet phd,i tinh den su bdo hba
a tlic tinh td h6a cua dQng co.
Til mach tudng drrOng hiuh 4.1b c6 th6'suy ra ctic cdng thf'c sau:
1- Phd.n
[fol' *kifr]
"
1r.",
[[+]'
l'
= n,
+(x'+x"'rli" = r?x)1,
(4.59)
(4.60
)
Tt
cdc c6ng thrlc (4.59) - (4.61) suy ra:
ry=#
'-
x^
TrI bidu thrlc (4.59):
M6men dQng co slrh ra:
m
,l
L
= 0Jatt;z&z
- s
(
Tdng trd ng6 vdo mach ttrong drrong cria dQng co:
Zin = (&
+;&)
+
b+ j(x^ + xr)
= Ri, +jXro
s
R"
trong d6:
Rin=*t*ffi X*,
Xio = Xt+
t+)
+(x^+X)2
v =I?@k+x'?")
C6c cOng thrlc tt (4.59) tldn (a'65) ld phi tuydn do quan hQ phi
giita E vd. I^-Vdi quan hc E(I) cho trudc, tinh todn d{c tinh co cfia
tnldng hgp ndy c6 thd ti6'n hdnh theo trinh tqt sau:
: Chgn grd t4 I* (I^ < I),
co trong
- Tinh E vd,X^ tU dac tinh tt
- Tinh f'2 fi cOng t}l;fic (4.62),
h6aE(I)'
tudng rlng cria s trl c6ng thrlc (4.63)'
(
- Tinh mOmen dQng co vh diQn 6p stator bhng cOng thrlc (4'64) vh
- Tinh gi6
tri
co
KDB - DtEu KHTEN r6c oQ DeNe
co
KDB
Tr6n hinh 4.17, d{c tinh
cfia mQt DCKDB khi cung
llp bdi ngudn ddng vdi cdc
Jd tri kh6c nhau cria dbng
ngu6n f1 tlrrgc v6 blng drrdng
D{t lidn, cbn dic tinh co cria
d0ng cd khi cung cdp bdi
ngudn dp rlinh mrlc (vd'i tdn
td tlinh mrlc) vE blng tlrrdng
ndt tlft. TrOn hinh ndy, c6
thd tfrdy m6men khdi dQng
o0a tlQng co khi cung cdp
Hinh 4.77: DQc tinh dQng co kh6ng
blng ngudn dbng nh6 hon
d6ng bQ hoat dQng udi ngu6n ddng &
nhidu so vdi khi cung cdp
tdn sd dlnh mtc
bXng ngudn dp, do tit th6ng
tlQng co (trrong rtng vdi I^) vd
rfbng r6to f2 n,bL6 hon nhidu so vdi khi cung cdp bXng ngudn 6p.
X6t tlidm ldm vi€c I vit 2 tr6n ddc tinh co cung cdp bdi ngu6n ddng
(1I.4.17). T4i cd hai didm ndy, dQng co sinh ra cing mQt m6rnen.
- Didm 1 cfrng nlm tr6n d{c tinh cd cung cdp bdi ngudn dp tlinh
mti'c, do d6, tai didm 1, dOng co ldm viQc vdi tir th6ng dinh mrl'c vd diQn
dp cung cdp
dfnh mrlc.
- Didm 2, diQn dp cung cdp cho dQng co cao hdn tlidm 1 n6n dQng
cd sO 6 tr4ng thdi b6o hba vir tdn hao tr6n dQng cd s6 cao hon khi ldm
viQc thi ilidm 1.
Tdng qudt, didm lAm viQc 1 s6 tdt hcrn didm 2. Tuy nhi6n, clidm 1 6
tr€n vtng kh6ng dn itinh cria d{c tinh co, vl ndu mudn dQng co lAm viQc
lr€n ving ndy, hQ thdng cdn dtroc thidt kd theo kidu vdng kin vd ph6i c6
b0 hieu chlnh thich hop.
Suy rQng ra, qui tich c6c didm ldm viQc nhrr didm 1 khi ddng .I1
thay ddi chinh li tlrrdng tl{c tinh co cfia dQng co khi cung cdp b6i ngudn
lp tlinh mrlc (vdi tdn sd dinh mfc) v6 blng tlrrdng n6t drft. N6i khdc di,
hlnh 4.16 cho thdy,vdi m6i gi6 tri cho trrJdc cria f1, c6 mQt gi6 tri tudng
rtng cria tdc tlQ tnrd all tld tlQng cd se lem viQc vdi ttt thOng tlinh mfc
Ddng kh6ng tAi
fltnh
4.78: Quan hQ
I{q)
dd
tt
th6ng dQng co Id. dlnh
rruXc
Ngodi ra, ta c6:
71'1
L
= o)at 4zdz- s
Thay vio bidu thrlc tr6n gid
3
M= 0Jat
tri cria 4
I?x"^
tU bidu thrlc (4.60), ta
+
+(x,+x)2
ofluo co
KDB -
orEu xutEtt r6c
N
oeua co KDB
147
cdc
thd
Ir^
2
Ir^ =
tAn
khi
nd.y
vdi
P-
@.72)
TrI c:ic bidu thrlc (4.
rnrlc vdi moi gid tri cria
cAn th6a:
bng td h6a I* li dinh
.I"r, bidu thrl'c sau d6y
&
i
t-
t*l
DEng thrlc
+(x*+x)2
.91
4 Yl-+ (x*+xr)2
Lt A1
niy d5n td'i:
s(I=sJ
Nhdn hai vd cta (4.73) vdi
(4.73)
coau,
suy ra:
:vF-
DEng thric trdn c6 thd di6n
giii f
Tdc dQ truqt tqi tdn sd afa^
-
nghia
Ii:
Tdc dQ truqt
tqi tdn
sd f6^
Bidu thrlc (4.74) cho thdy tai mQt gid td nAo d6 eria ngudn dbng f
tdc d0 trugt ma tai.d6 ldm cho tlQng co hoat dQng vdi tir th6ng dinh
tai tdn sd dfnh mrlc cfrng ldm cho dQng co ho4t dQng vdi tir th6ng di
mrlc tai moi tdn sd khdc (f < fa).Tt dAy, quan hQ fr(oxr) tld tlOng co
viQc vdi tr} th6ng tlinh mrlc tai tdn sd dinh mrlc - nhu dd khAo sdt &
tr6n - cfing dfng vdi moi tdn sdkhdc.
Ktri ldm viQc d tAn s6' f = afa^ vA til th6ng dQng co drroc gifi
dlnh mr?c, m6men dQng co sinh ra c6 thd tinh tt bidu thric (4.70) v6i
g,id tri cfia X thay bXng aX, ta c6:
Vdi mQt gi6 tri nd.o dd cria ngudn dbng -I1, ndu tdc d0 truot c+r
gifr kh6ng ddi, m6men dQng co sinh ra cfing khdng tldi t4i moi tdn sdf.
Ddc tinh co cfia dQng co khi hoat tlQng vdi ngudn dbng cung cdp
til th6ng gifr blng dinh mfc cho tr6n hinh 4.19.
Dlc
ttnh cd khi ldm viQg vdi bi6n tAn ngudn dOng vA tU th6ng giB
blng dlnh
-: -: Dic ttnh cd khi lAm viQc vdi c6c ngudn ddng lr khdc nhau
FJlnh 4.79: Ddc ti.nh co crta DCKDB ld.m uiQe udi bi6n tdn ngu6n ddng
--
'
olxa
"o
*ot'o'Eu *H'E*'d" w fi
T't
t49
rAu - sOnc cd
q.z stt sd rHdr nE rHdHc s0 srEH
&p 'd'Qng co
tndng UO Uidn tdn ngu6n
khi tai thdp,
tdn hao tr6n tlQng co
h6a
ttridu
tdi
cdn
Tril trrrdng hop
bidn tdn co bAn ld:
phuong 6n didu ktridn
hAu nhu
gifr til th6ng tlQng co
mrlc'
dinh
hon
- Vei tAn sd thdp
l'nA
kh6ng ddi
(vd
6p stator ld khdng ddi
iliQn
giir
mfc'
tlinh
- Vei tdn s6 cao hon
ou"trTll*1l."iru
bidn
Dc, ddng di.n cria bo
,nu"* tridu khidn dQng co
chd ddng
Uot'* hoic mach han
u*
tidp
hdi
vOng
nf'tr
tdn tluoc han chd
tidp th6ng qua viQc tlidu
gi6n
c6 thd dugc han chd
gifr
diQn. Ddng diQn cfrng
til th6ng dQng co tlrroc
y
khi
le
Lrtu
co'
dQng
khidn tdc tlg t"rgt Jt
tdc dO trudt cfia
stator'
gi6 tri x6c dlnh cria dbng
kh6ng ddi, vdi mQt
ddi' ndu gi6 tri
vLng til thdng khOng
trong
d6'
Do
sd'
dQng co Ii hhng
dbng stator dQng co
mOt giri tri niro d6'
6
chd
han
bi
cfia tdc dO trudt
dd dOng co hoat
CUng cAn lrru i lh
rlng'
tudng
*f'
cflng bi gidi han a
nlng cung cap m6men
vd hiQu sudt cao' khA
sudt
cOng
sd
hQ
dQng vdi
tri tdc clO trrrgt tai m6men
co cAn nh6 hon gi6
aO"g
tnrot
tdt, tdc dQ
"tit
tdi han cria dQng co'
c6 m6men
dOng' nhdt th cric hQ
truydn
thdng
hO
-thdng
Vdi nhi.u
D6 la
viQc 6 chd d0 him'
cdn c6 ktra tng ldm
thdng
f'C
qu6n tinh "to'
phdt vh n6ng
am s6 tr6 thdnh mriy
trudt
d0
vdi
viQc
hnr cria
vi tlQng co khi IDrm
U rr-*: tu chinh
cho
n4p
si
neV
hic
ra
'o ln:
iliQn 6p
Irrgng do dQng co sinh
viQc 6 trang th6i h6m'
ldm
thd
khOng
hO thdng
bO bidn tAn' Khi
ki6n brin d6n trong
cao ldm h6ng cric linh
t6ng
thd
c6
ndy
tr6n tu loc
bidn tdn' chd
Tny theo cdu trric bQ
khidn'
ttidu
*a"ft
*
mach tlQng Irrc
d0h6mcOt'trdldhdmtlQngnlngho{ch6mt6isinh' vbng hd cira mQt b0
hC thdng tliOu khidn
Hinh 4'20 ld so dd khdi
bidntdnkiduttidurQngxung(PwM)lhmviQctheoquyluitV|f=CofLSt
ning'
6 chd t10 ham tlong
tlOng
I
I
Ngu6n AC
BQ nghich
Tdc d6
luu PWM
dit
KhAu Qo trd
Khau hdi tidp ddng
Hinh 4.20: BQ bidn tdn udng he pWM uoi hdm dQng nd,ng
Khau tao tr6 nhxm muc dfch dd tdc dQ dgng co bidn thi6n
kip vdi su
thay ddi cria t6'c do d4t, nhlm trdnh cho h6 thdng dao dQng
khi t6c dQ
d{t bidn thi6n.
Tr6n hinh 4.27, so dd kh6i mot h0 th6'ng didu khidn vbng
kfn dQng
co khOng ddng bQ st? dung bQ bidn tdn kidu didu rQng
xung, c6 vbns hdi
r
DQNa
co
KDB - DtEu KHTEN
rdc o0
oONa
co
151
KDB
Ngu6n AC
Kh6u hiOu chlnh
vdng dien 5p
Rh
rdc dQ dgt
IS
KhAu hiOu chinh
tdc
I'
Kha, rrdi tilp oong
Mdy phdt tdc
Hinh 4.21: BQ bidn tiin udng kin kidu PWM udi hum dQng ndng
KhAu hiQu chinh vdng tdc d0 ld khAu PI nhim muc dich ldm sai sd
xdc l{p tdc d0 bXng zero. Sai sd e, gif,a t6'c d0 Cl4t vd tdc d0 thrrc drroc xrl
ly qua khdu PI ndy vd khdu tao hdm dd tao ra tin hiQu /i cdn thidt.
tr6n co sd quan hQ gifra t6'c d0 trudt ve
tldng stator ild gifr tt th6ng trong khe hd kh6ng khi la kh6ng tldi. Tdn
so f drra ra drJoc hiQu chinh sao cho t6'c d0 thrrc bXng tdc d0 tl4t. TrI tin
hiQu tdn s6'f, diQn :ip tudng rlng cria b0 bidn tdn duoc dua ra theo, quy
luAt V* = Kf + %. Ndu tin higu f > fa^, diQn rip ra s6 duoc gifr cd dinh vd
blng md'c dien 5p cho ph6p ra ldn nhdt cria b0 bidn tdn, hic ndy hQ
KhAu tao hdm duoc x6y drrng
th6'ng ldm viQc d chd d0 diQn dp kh6ng ddi.
KhAu han chd dbng diQn tlrroc thidt kd dd han chd dbng cung cdp tU
b0 bidn tdn khdng vudt qud mri'c cho ph6p tlinh tnJdc. Khi tin hi6u ildt
tdc d0 ting l6n theo hdm nde, khAu han chd ddng sE drroc kich hoat. Khi
d6, sai sd e1 s6 tdng chfm dAn d6h tAn sd, vd tuong ritrg ld di6n :ip ra,
cfia bQ bidn tdn s6 tdng ch{m. DOng co duoc gia tdc vdi dbng dign vd
gid tri d4t <ox, ddns
m6men cuc dai cho ph6p. Khi tdc d0 dOne cd dat
r52
chd dbng ciing hoat dQng tudng tu nhu m6 tA
han chd ddng diQn blng cd,ch gilm t6'c d0 thay ddi cria tdn sd. Lw
khi giAm tdc, hQ thdng lim viQc 6 ch6 d0 hdm dQng ndng nhd
h6m clQng ning drrgc kich hoat dQng.
d{t gi6m, kh6u h4n
Ngudn AC
KhAu hi€u chlnh
KhAu didu khidn
td th6ng
KhAu hiQu chlnh
tdc d0
Mtiy
Hinh 4.22: BQ bidn td.n udng hin kidu PWM, didu khidn tdc dQ truot
ud. hd,m tdi sinh
Ddng diQn ciing c6 thd drrgc han chd drrdi mQt gid tri cho ph6p q
viQc clidu khidn gi6n tidp th6ng qua tdc tlQ tnrdt nhu hQ thdng
hinh 4.22. HQ thdng ndy ciing srl dung b0 chinh hnr k6p dd thrr. c
hdm tdi sinh dQng co.
Trong hQ thdng h\nh 4.22, sai sd tdc d0 tlrrgc x(r Ii qua khdu PI
khAu didu chinh t6'c d0 trdot. KhAu didu chinh tdc d0 trrrgt dua ra
hiQu tdc d0 trrJot or"r* cdn thidt cho dQng co. KhAu didu chinh tdc d0 t
ld khdu beo hda, do d6 tdc dO trudt bf h4n chd 6 mQt gid tri dinh
vd d6n ddn ddng clQng co cfrng bi han chd d mQt mrlc dinh ttt6c.
Tdc d0 ddng b0 cdn cung cdp cho dQng co Id tdng cfia tdc d0 thgc
D1NG
cd
KDB -
aeu
KHI€N
rdc o0
oQrto co KDB
153
diQn 6p cdn cung cdp cho dQng co. KhAu tao hdm bidn tltii tin hiQu tdn
s6' cdn thidt / thdnh gi6 tri cliOn rip cdn cung cap cho dQng co V*, bdo
dim he thdng hoat dQng d chd dq tU th6ng khong adi vdi f < fu,, vd 6
chd dO diQn rip kh6ng aldi vdi f > fa,,.Dien rip ra duo-c girl d mf'c cliQn aip
det V* nhd vbng hdi tidp diQn rip.
Khi tin hiQu tdc d.O d?t ting, sO dAn den sai so tdc dQ tdng vi ng6
ra kh6u di6u chinh t6'c d6 trrJot ci' mfc bao hda. Khi dd, t6'c d6 trrrot o.1+
s6 d mfc cao nhdt. HO thdng sd gia toc voi doDg cho phep lol1 Dhdt, vd
tudng rl'ng Id m6men ld'n nhat, cho td'i khi tdc dQ thrrc tlat gdn bing giri
tri ddt. Khi d6, tdc dO trudt o.r'r sE ci mfc xric l4p sao cho dQug co sinh
ra m6men cAu thidt dO cAn b)irrg v<1i rnornen tdi.
hiQu t6c do ddt gidrn, sai so tdc d6 ld arn. Khau di6u chinh
tdc d0 trrJdt s6 dua ra tin hiQu tD"1t' dm d' mf'c bio hba. Lfc nhy, dQng co
ldm viQc d chd clQ hdm t6i siDh, dQng co duo-c didu khidn girirn toc voi
Khi tin
dbng diQn cho ph6p crrc dai cho td'i khi tdc d0 dong co' dat mtlc tdc d6
dat.
B0 bidn tAn stl dung nguy6u ly didu khi6n tdc clQ trudt dudc st
dung khri r6ng rai do viQc didu khi6n trrrc tidp t6'c dO trrrot biio dtim hO
thdng hoat dQng dn dinh d uroi toc d0, ddp f'[g ilhanh va trdnh duoc
viQc sfi dung c:ic mach hdi tidp dbng c6 giri thAnh cao.
2- He thdng bQ bidn td'n ngu6n dbng
'
dQng co
Hoat dQng cria dQDg co khong d6ug bQ v6'i bieD tdrr DgudD ddng
drrgc khdo sdt trong muc 4.6. C:ic chd ttQ hoat dQng ciia dQng co v6'i bQ
bidn tdn ngudn ddng crlug trlo[g tu nhrJ he thoug vdi bQ biel] tAlr ngudlr
eip. He thong thudng duo-c thidt kd da hoat dQng v6'i tii th6ng kh6ng
d6i d tAn so nh6 hon dinh mrfc. V<li tdn so hoat dQng cao hdn dinh urfc,
he th0'ng hoat dQng vd'i chd dO diQu rip kh6ng doi'
Khi hoat clQng vdi tdn sd drro'i dinh mr,lc, tit th6Dg duoc girr khoDg
Cldi neu quan hQ gifia ddug stator 1r vd toc dO trucrt 1'r.1 dudc cluy tri theo
qual hQ 1hu hinh 4.18. Vi ddug 1,i cLia bo chinh luu tlortg bd bien tdu ti
IQ vdi /1 n€n clng c6 th6 tinh la quarr hQ tuong trr gio.r 1,/ va (D./. cuug
cdn lrru y la khi ldm viQc vdi tit th61g dinh rnfc, di6m Iam viQc cria
dQng co thttdng d' tr6n doaD kh6ng dD diuh cria dzic tinh co', do d6, h6
th6'ng b{t buQc phrii ld hQ thO'ng di6u khi6n vdng kin,
154
CHUONG 4
KhAu hi€u chinh
vdng d6ng diQn Mgch kich
Ngu6n AC
KhAu didu khidn
trl th6ng
KhAu hiQu chlnh
tOc d0
Mdv
Hinh 4.28: Bidn tdn ngu6n ddng didu khidn tdc d6 truot
So dd khdi mQt hQ thdng di6u khidn bidn tdn ngudn dbng kidu vdng
kin cho tr6n hinh 4.23. Tin hiQu sai so'tdc dQ duoc dua ddn khdu hi6u
chinh PI vi khau di6u chinh tdc dO trudt trong vdng di6u chinh tdc d0.
Tin hiQu t6'c d0 tnrdt ro"7 drroc cQng vdi t6'c dQ thrrc ar dd tao thdnh tin
hi6u t6'c tls ddng bQ cdn thidt, til d6 xdc dinh tdn sd ra cria bQ bich tdn.
cflng drra tron tin hi6u tdc dQ truot or"r d ng6 vdo, kh6.u didu chlnh tt
th6ng s6 tao ra tin hiQu fu* cAn thidt dua tdi tlidu khidn bQ chinh hnr dd
t4o ra ddng chinh lrru tuong ri'ng, nhlm ddm bdo dgng co lam viQc vdi tt
thdng kh6ng aldi.
Khi sai sd tdc d6 > 0, tin hiQu tdc tlQ trrrdt or"1 c0ng duong, vA hQ
thdng drroc gia tO'c trong chd d0 dQng co dC'n khi dat t6'c d6 y6u cdu. Khi
sai sd t6'c d0 < 0, tdc dQ truot ro"; s6 c6 ddu Am, t4o ra tdc tlQ tldng b6 cria
dQng co th{p hon t6'c d0 dQng co. Khi d6, hQ thdng ldm viQc d chd dO
hdm tdi sinh vd gi6m t6'c ddn tdc dq y6u cdu. Tin hiQu tdc do trudt d ng6
ra cfia khau didu chinh t6'c tlQ trrrot drroc gidi han & mQt mrlc dinh tnr6c,
khidn dbng ng6 ra 16 cfa bQ chinh lu.r, vd. tudng rlng ld dbng stator dQng
cd, dugc gidi han d mrlc dinh trudc. Do d6, qud trinh tdng tdc vi gi6m
y4w
tdc
00ua co rcoa -
oAu xutEu r6c
&
o2r'rc
ca
KDB
lud trinh tdng girim tdc tlQng co sE ho4t tlgng vdi m6men crr. c d4i cho
nhrr cdc didm vd tr6n tlrrdng n6t drit, tr6n hinh 4.23 vit,tudng fng'
th6'ng s6 c6 d6p rlng qud d0 nhanh.
Vdi tdc d0 cao hon tlinh mrlc, diQn rip cung cdp cho dQng co s6 duoc
khidn gifr d gi6 tri dinh mric. Lric ndy, hQ thdng ho4t clqng d chd d0
g sudt kh6ng ddi viQc didu khidn tt th6ng khdng tldi kh6ng cbn tdc
Dd c6 thd didu khidn dbng ra cria bQ bidn tdn l6n ddn dinh mrlc,
tri gidi han cfia t6'c dQ trugt o", cdn ting l6n tuydn tinh theo tdn sd
cria bQ bidn tdn. ViQc ndy duoc thrrc hiQn blng c6ch cQng th6m vio
ra cfia khdu di6u chlnh t6'c dO trLrdt mQt tin hiQu t6'c d0 trddt phu ti
vdi tdn s6'vd c6 ddu thich hop.
Khdu hiQu
chlnh t6c d0
KhAu ldy tri
t
ddi
Kdau hiCu chlnh
vdng ddng diQn Mach kich
Ngudn AC
ao
Khau hdi tidp dong
L
lt.
M5v
Hinh 4.24: BQ bidn td.n ngudn ddng di6u khidn ddng diQn
Hinh 4.24 trinh bdy mQt so tld didu khidn bO bidn tdn ngudn dbng
c, kidu didu khidn theo dbng diQn, trong d6 tin hiQu tdc dQ tnrot cdn
a\r drlgc t4o ra tit tin hiQu ddng diQn /a.
Trong sd dd hinh 4.24, tin hiQu sai sd tdc rlQ duoc xfr lf qua khdu
chinh t6'c ttQ vd khAu ldy tri tuy€t d6'i tld tao ra tin hiQu dbng diQn
fu*. Dbng Ia ng6 ra cria bO chlnh lur drroc didu khidn tddng f'ng vdi
Ia, khdi didu khidn tt th6ng sinh ra tin hiQu tdc d0 trrJdt <4r tudng
dd duy tri tU th6ng dQng co ld kh6ng tldi. Tdng cria tin hiQu hdi tidp
dO dOng co ro vd tdc dO trudt oL, xdc dfnh tdn sd ldm viec cria bQ
tdn. Khi sai sd tdc d0 le > 0, t6'c d0 trrrgt drroc gdn ddu drrong tudng
vdi chd d0 ldm viQc dQng co. Khi sai sd tdc d0 ld < 0, tdc tlQ trugt
grin ddu dm trlong rirrg vdi chd tlQ ham.
Ng6 ra cria khdi tlidu khidn tr} th6ng duoc gidi han & mQt mri'c
tlinh trtrdc, d6n ddn dbng ra cfia bQ bi€h tdn drrgc gidi h4n 6 mQt
cho ph6p xdc dinh. ViQc gidi hin dbng ndy ctng khidn dQng co ldm
vd'i ddng crtc dai cho ph6p trong qud trinh qud dQ, lim cho qud
ttrng hodc giAm tdc cria dQng co di6n ra nhanh ch6ng.
chinh Imr dr)ng thyristor, cdn duy tri ddng chinh lur d
mfc ndo d6 dd sg chuydn mach cia cric thyristor duoc dAm b6o. Didu
dugc thu. c hiQn blng crich dn dinh mQt mrt'c tdi thidu cho ng5 ra cfia
ldy tri tuyQt tldi tren hinh 4.24.
3- So sd.nh bi€n td.n ngu6n d'p vd. bidn td'n ngu6n d.bng
MOt sd ul khuydt tlidm cria bidn tAn ngudn :lp vi bidn tdn
ddng dugc n6u ra drrdi dAy:
1- Trong bO bidn tdn ngudn dbng, khi hai kh6a bdn d6n trong
mQt nhdnh cria bQ nghich lrru cing d6n (do kich nhdm ho{c do
mach), ddng ngdn m4ch qua hai kh6a tlugc h4n chd d mric crr. c dai
dinh trudc do tdc dung cria mach didu khidn ngudn dbng chinh
Trong b0 bidn tdn ngudn dp, viQc ndy c6 thd gAy ra sU cd ng{n ma
ldm h6ng kh6a b6n d6n. Do d6, c6 thd xem bidn tdn ngudn dbng tin
vd ch6c chSn hon bidn tAn ngudn dp.
2- Do mach chinh lrru tao ngudn ddng c6 thd hoat dQng d chd d0
ndng lrrong vd lrrdi (nghich lur), b0 bidn tdn ngudn dbng d6 ddng
viQc d chd d0 hdm trii sinh. Vdi bQ bidn tAn ngudn 6p, d,6 hoat dQng
d chd d0 hdm tdi sinh, cdn th6m vdo hQ thdng mQt cdu chlnh lrru
khidn hoin toin.
Trong tnldng hop mdt ngu6n lrrd'i khi dang ho4t tlQng, bQ bidn
ngudn dp c6 thd hoat dQng d chd clO hem dQng ning, nhrrng b0 bidn
ngudn dbng kh6ng thd ho4t tlQng drroc & chd d0 ndy khi d6.
1- B0 bidn tdn ngudn ddng thrrdng s& dung cuQn khdng Ld k};.a
Vdi
bO
DANG
ca
KDB - DtEu KHEN
r6c o0
oQNa
co
KDB
L57
2- V6i bO bidn tAn ngudn 6p, d6 ddng 6p dung ki thu4t PWM dd
rlidu khidn tl6ng ngdt cdc kh6a bdn ddn. Kf thuat PWM cho ph6p gi6m
ldn hao do s6ng hdi gdy n6n tr€n dQng co, kh6ng gdy ra m6men d{p
rrrach ldm rung dQng co 6 t6c d0 thdp. Tuy nhi€n, kr thuat didu chd kidu
l'WM kh6 :ip dung vd'i bidn tdn ngu6n ddng, thrrbng chi c6 thd srl dung d
ttin sd hoat tlQng thdp.
3- Khi hoat dQng vdi ngudn cung cdp la DC (vi du: truy6n dQng cho
xe diQn), bO bidu tdn ngu6n 6p ggn vd 16 hon b0 bidn tdn ngudn dbng f,hudng cdng kdnh hon do phAi srl dung cuQn khdng La l6n vd cdc tu
t:huydn m4ch c6 gid tri cao.
4- Bidn tdn ngudn ddng kh6ng thd truy6n tlQng cl6ng thdi cho nhi6u
rlQng co, trong khi bidn tdn ngudn 6p c6 thd cung cdp ddng thdi cho
rrhidu dQng co (multi-motor driues).
5- Dai didu chinh tdn sd cria bidn tAn ngudn ddng thdp hon dAi didu
chlnh tdn sd cfia bidn tdn ngudn rip.
4.8 DrEu KHTEN cOnc sufir TRU0T DONG cd R0T0 oAv ouAtl
Phdn ndy sO trinh bdy c6c phrrong ph6p clidu khidn c6ng sudt trrrot
c6 thd 6p dgng vdi dQng cd kh6ng ddng b0 r6to dAy qudn.
MQt phAn cria c6ng:sudt diQn tt truy6n qua khe hd kh6ng khi gifra
stator vd rdto kh6ng tlrroc bidn thdnh ndng luong co, phdn c6ng sudt ndy
goi Id c6ng sudt trudt. C6c phrronC ph6p dieu khidn c6ng sudt trudt so
nhlm tlidu khidn lugng c6ng sudt ndy. Do d6, vdi c[ng mQt ltrong c6ng
sudt tliqn til drra vdo r6to, lrrgng c6ng sudt cd dua ra tai s6 thay ddi va
din tldn viQc t6'c dQ dQng co drJoc thay ddi. Cdc phuong ph6p didu khidn
c6ng sudt tnrdt sf/ dung ki thu4t cliQn tfi c6ng sudt c6 thd kd ddn li:
1- Di6u khidn xung diQn
2- HQ ndi tdng
trd r6to'
linh (static scherbius driue)
4.e HE srEu xuliN xuNc olEn
rnd noro
So tld hQ truydn tlQng dtng phrrong phdp clidu khidn xung diQn trd
r6to c6 so tld nguy6n lf nhrr hinh 4.25.
Hinh 4.25: Didu khidn xung dien ft6 r6to DCKDB r6to diy qudn
DiQn trd r6to drrgc thay ddi dtng nguy6n lf chopper. Phuong
ndy cho ph6p didu khidn v6 cdp tliQn trd r6to, vd tudng rlng, ld tdc
dQng co. Hinh 4.25 cho thdy diQn dp xoay chi6u d r6to drroc bidn
thdnh mQt chidu qua cdu chinh lrru diode ba pha vd cung cdp cho
trd R gdn b6n ngodi tlQng co. Kh6a bdn d6n S gdn song song vdi R,
cit vdi chu k| T, trotg dd thdi gian d6n cfia kh6a le. U,. Khi fo" thay
trong khoing 0 ddn T, gi6 tri tuong tlrrong cria R thay ddi trong
R tldn 0. CuQn khdng loc L6 nhlm san phing dbng .I2. CuQn khdng I
cfing girip dbng 16 duy tri chd d0 ddng li6n tuc khi dQng co mang
thdp.
DQng co kh6ng ddng bO thudng duoc thi6t kdvdi ti sd vbng
stator / fito nh6 hon 1, do d6 dien dp chlnh lrru Va thrrdng thdp. Do
kh6a bdn d6n S thudng dtrng transistor c6ng sudt le thich hop hon
Vdi hO th6'ng c6ng sudt ldn, GTO ciing c6 thd tluoc srl dgng.
Khi gidi tich, cda giA. thidt eau d.tlgc d.p d.ttng uoi hQ thdng
1- 86 qua hiQn tuQng trirng d6n xAy ra trong cdu chlnh lur diode
diQn khdng tAn cria tlQng co gdy ra.
2- Dbng.Ia xem ld li6n tgc vd phEng
3- Vdi cdc gi| thidt 1 vi 2, dbng pha trong rdto c6 dang vu6ng
hinh 4.26. Do d6, r6to c6 thd clrrgc xem lA dugc cung cdp til m6t n
oQNo
co
KDB - orEu xutEN
rdc oQ D2NG co KDB
trong khe hd kh6ng khi c6 thd dr.roc xem ld c6 dang sin. Khi tt th6ng c6
dqng sin, m6men dQng co sinh ra li kdt quA cria su tr.Idng tdc gifra hdi
b$c 1 cfia ddng r6to vA tU th6ng. Ddng hdi r6to chi sinh ra mdmen ddp
mach vd tdn hao phu.
4- Tdn hao tr6n cdu diode vd kh6a brin d6n c6 thd xem
li
khdng
ddng kd.
i
i\t---I
/,
Hinh 4.26: Dqng s6ng ddng ud. tip ffAn r6to (cdc dgi luqng pha)
Mgah tddrlg ddong crta hQ thdng
Tuong tg nhu b0 chopper, ta dinh nghia h0 sd didu chinh y
1-
'T= 4
y
chu
@.76)
Ndu don s6ng dbng ft b6 qua, ndng luong hdp thu bdi R trong mQt
d6ng ngdt T s6 ld:
Wn= I2aR(T-t")
k)
COng sudt trung
binh hdp thu bEi R trong mQt chu
P, =
k):
+lr'oR@ -t.,)]
Tir tlfnh nghia hQ sd tli6u chinh T suy ra:
p,
= I?R(t-y)
V{y, gi6 tri dEng tri cria di6n trd R s6 ld:
R*=(1 T)R
Til hinh 4.26, gif tri hiQu dqng (rms) cria ddng r6to (dbng pha)
(4.77)
li:
(L
CHUONG 4
160
PhAn tich d4ng s6ng dbng rOto tr6n hinh 4.26 blng chu6i Fourier,
nhQn tluoc tri hi€u dqng hdi co bin (hhi b{c 1) cfia dbng pha rdto (quan
sdt phia r6to):
6
ila
(4.7s)
= n1r,^"
(4.80)
Ir =
Tir (4.78) vd (4.79):
Iz
Ggi Ra ld tliQn trd cu6n d6y L6, tdng tliQn trd tAi tudng duong cria
cdu chinh lur"r Id:
Rn=Ra+R*=Rd+(1
-lR
C0ng sudt ti6u thr,r tr6n mQt pha rOto b&i mach didu khidn xung diQn tr&:
p"
Thay gi6 trf
16
1
-= il,ofno +(r-T)R]
trong c6ng thrl'c (4.78) vdo cdng thrl'c tr6n:
P"
= 0,5 [n,
+ (r
- y)n]
I,^"
C6ng sudt ney tudng tlrrong vdi c6ng sudt ticu tdn. gdy ra bdi ddng
hiQu dung I"-" tr6n mQt diQn trd d8ng tri c6 gi6 tri 0,5[Ra + (l-y)R] mdc
vdo tirng pha cria r6to. Do d6, diQn trd tlEng tri cfia mach xung tliQn trd
tr6n m6i pha r6to ld:
(4.81)
R),=0,5[Ra+Q-iR]
Cdn n6i th€m d dAy Id m4ch tudng drrong cria tlQng co dang tinh
to:in dd rrit ra d dAy ld mach trrong drrong rfurg vdi hdi co b6n (b4c 1)'
M4ch tudng tlrrcnrg drtgc suy ra trdn nguyen tdc bAo toin c6ng sudt: bidu
di6n tlugc mdi quan h0 giila cdc hdi b{c 1 crla dbng diQn vd diQn 6p trong
dQng co, ddng thdi c[ng cho ph6p kd ddn tdn hao do cdc s6ng hAi gAy ra.
Trong mach trtong cluong ndy, frng vdi thdnh phdn b4c 1 cria dbng
diQn, cdng sudt tlien tt truydn qua khe hd kh6ng khi tdi r6to lA:
(4.82)
Par = 3E'12' cos9,
trong d6: 0, - ld g6c lQch pha gif,a v6cto E vd' Iz.
C6ng sudt diQn til ndy cOng ld c6ng sudt ti6u thu bdi m4ch r6to:
(4.83)
Pa,=317^"@2+ Rlp+f"
-
sudt co dua ra
tii.
gplo co
KDB - otEu xurEN
rdc
oO oeNa co KDB
161
Thay (4.80) vdo (4.83), ta c6:
,0,=*rg@2+ R|,)+p"
TU (4.82) vA (4.83)
ta
(4.84)
c6:
4
El2coso,=!Bfn"*nl''
- a')*T
(4'85)
9
COng sudt tnrdt tudng rlrrg vdi thAnh phdn hdi bAc
1
c&a ddng r6to:
spau-gI3@r+ R),)
(4.86)
trong d6: P6.a -Id c6ng sudt diQn trl rlng vdi thAnh phdn hdi co brin.
COng sudt co sinh ra bdi dbng r6to b4c 1 (hni co b6n) ld:
P"=(7-s)Part
Thay c6ng thrl'c (4.86) vdo cOng thrlc tr6n:
P" = 3
t|{n, + nl,,t (1-s)
@.87)
s
Thay c6ng thrlc (4.87) vdo (4.8b) vd s{p xdp lai:
(4.88)
(*2
\
l(n"+nu,)
\"
)
R1= (R2+ nl*)
Rn=
li-r
(4.8e)
(4.e0)
Trong bidu thrl'c (4.88), cdc dai lugng vd phdi Id c6c dai lrrong phia
Quy ddi vd phia stator, bidu thrlc (4.88) trd thdnh:
Elrcoso,=
d6: R1, vi
["t
R1
.*)r;
tudng tlng vdi cdc gi6
(4.e1)
tri
cria .Rn vd
ftr euy ddi
vd
stator nhu sau:
En = SrRo
Er =
a?tar
i art - ti s6'vdng dAy stator/r6'to.
e.g2)
Mgch hJdng drrong mQt pha cria dQng cd quy ddi vd stator khi
dung nguy6n lf didu khidn xung tliQn trd r6to nhrt hinh 4.27a.
lrrgng tren diQn b6 (Es /s) bidu di6n phdn nting luqng tq.o ra co nttng
tdn hao d6ng ffAn r6to gd,y ra do thdnh phdn hd.i co bdn crta ddng
Ndng lrrgng tr6n diQn ft& R1 d{c tnrng cho tdn han d6ng sinh ra
r6to do thd.nh phdn hd.i cila ddng rilto. M4ch tudng tluong hinh 4.27b
mqch tudng tluong don giAn h6a cria hinh 4.27a.
A;
Ri/s
"l
a)
o,
'l
Hinh 4.27: Mgch tuong duong crta dQng co trong trudng hop srt dpng
mach didu khidn xung diQn trd r\to
2- Ddp fing efia hQ thdne
Dd tlon gi6!, sfr dgng m4ch tudng tlrrong
hinh 4.27b. Dbng
rOto
hic nDry tinh theo cdng thrlc:
fz=
v
R, * E^+9+ j(Xt+Xz)
s
o'
M6men dQng co sinh ra:
b \zEr = 3
M= (Dat
()db
s
v2L
s
(4.94
Nhrr vQy vdi gid tri cho tnldc cria y vi dO tnrgt s, c6 thd tinh
t4 .R; vbr Rltheo cdc cOng thrlc (4.89), (4.90) vd (4.92). TU tl6,
cilc gi6
thd tinh duoc ddng r6to vd m6men dQng co theo cdc bidu thrlc (4.93)
@.94).
I
biy c6c ddp rlng dbng, v{n tdc vd m6men dQng
pha
r$to dfly qudn (50kW, 44OV,60Hz) vdi m6men tfli
kh6ng d6ng b0 ba
li 200Nm, ttidu khidn tl sd y tU I xudng 0,5 (ttiQn trd mdc phia bQ
Hinh 4.28 trinh
chopperR=2Cl).
co KDB - otEu xutEN rdc oe oeva cd
F
KDB
163
400
1
1200
1000
-c
\CL
9
aoo
.d
E
600
€
400
200
1,5 2
2,s 3
3,5 4
4.5
thoi gian, [sj
a) VQn tdc dQng cc tng udi tt sd d6ng y=
300
250
3.200
=5 1s0
E
o
E
,oo
50
-1
1,5 2
2,5 3
3,5 4
rhdi gian ls]
b) M6m.en dQng co
tng uoi y=
1400
1200
Fooo
E)
a
€q
Boo
G
t
ooo
400
200;
1,5
2
2,5
4.5
l
1
250
!r"..,, [.[firuulmnmmffi
E2OO
.'
z_
5 lso lltt
r' uluhilutilltttrilmffimnl
c
o
E
-
100
50
-0
d.)
M6men dQng co
2,5 3
t.5 gian2
0,5
thdi
lsl
khi ilidu chtnh tl sd y=
3,5
0'5 6 thdi d'idm
50
40
30
a
-20
810
o
60
;c -10
3 -20
-30
-40
-50
2"4 2,5 2,o 2'7 2'8
ffiTn
2,e
3
thdi gian, [sl
e) Ddng
rdto khi
T
= 0,5
E
do
c
30
.O>
t yj20
cf
dt
c
,o
o
E
zsos
zv
z,s1s 2'52 2,525 2,s3 2,5ss 2,54 2,345
thdi gian [s]
fl Ddng qua dian ff6 Phu R khi T= 0,5
t = 7s
oQNe
co
KDB - otEu rcnEn
rdc o0
D2NG
cd
KDB
165
Hinh 4.29 ld ddc tinh co cfia hQ thdng truydn d6ng sfi dung nguyOn
lf tli6u khidn xung diQn trd r6to. vdi y = 1, R duoc no-i tdt hodn toin bdi
kh6a bdn d6n S. Tuy nhi6n, cl4c tinh co vdi y = I thdp hon dnc tinh co tg
nhi6n do c6 th6m c6c tdn hao phu tr6n kh6a bdn d5n S, tr6n diQn trd
cuQn khdng lgc R6, vA tdn hao phu do s6ng hii ddng r6to. Vdi mOmen t6i
cho trudc, t6'c d0 gi6m khi 1 giim. Vdng didu chinh tdc dO nlm trong
ving gidi han bdi ABCD. Ving didu chinh c6 thd md rQng blng c6ch
tdng th6m giri tri cria diQn fi6 R.
1>Tr>yz>o
DC
Hinh
4.29: Ddc
tinh
co crta h9 thdng
st
d4tng nguyAn
l!
di6u khidn xung diAn trd r6to
4.10 HE ndl rAuc riNH (scHFB Btus DRtvE)
1- Gidi thiQu
Trong hq ndi tAng tinh, c6ng sudt trudt thay vi ti6u tdn tr6n diQn
nguyGn lf drra ra bdi
Scherbius. HQ n6'i tdng tinh Scherbius c6 so dd nguy6n lf nhrr hinh 4.30.
Luu y lA hQ chi hoat dQng drroc vdi tdc tlQ thdp hon tdc ilQ cl6ng bQ itinh
mfc quy dinh b&i tdn sd lrrdi tliQn.
trd phu r6to s6 drrgc dua trri vd stator theo
Trong hinh 4.30, cdu diode bidn ddi phdn ldn c6ng sudt tnrot thAnh
tlai luong mQt chidu. Sau d6, phAn c6ng sudt nly drroc trA v6 tuCi diqn
xoay chi6u ba pha qua mQt bQ nghich lrru chuydn mach lrrdi vA mQt bidn
dp ph6'i hop. CuQn khdng loc L6 gidi han srr gi6n doan ddng r6to khi tdi
166
Khi gi6i tich hQ thdng ndi tdng tinh, cdc gi6 thidt tU 1-4 trinh
trong mgc 4.9 (hQ tlidu khidn xung diQn trd r6to) v6n dugc 6p
dAy. Ngoii ra, cdn th6m cdc gii thidt sau:
1- Bidn dp dugc giA thidt li lf trrdng, nghia lA khOng c6 diQn
tAn, kh6ng c6 tdn hao vi dang s6ng ddng ng6 ra cfia bQ inverter
ph6n 6nh chinh xdc d phia bidn dp ndi vdi lrrdi.
2- Til gie thi6t tr6n, c6 thd b6 qua hiQn trr{ng tring d6n trong
nghich hnr gAy ra do diQn khdng tdn cfia bidn 6p.
86 qua sgt dp g|y ta tr6n mgch stator vd r6to, diQn 6p ra cfia
chlnh lrru c6 thd tinh theo diQn dp pha d{t vdo stator theo c6ng thrlc:
u,=Ti
r,3Gs.V
@
ludi cung cdp cho stator dQng co;
a71 - 11 sdvbng ddy qudn stator/ r6to.
trong d6 V - di€n dp pha
cria
Cong
sudtrevd
tudi
IT
3 pha
C6ng
sudt vao
Ir
I
chlnh
trru
B0 nghich luu
8rr
COng
sudttnJot
I
lr.,ra"r'
ri"4;Vll li: flll,,uo
Htnh 4.80: HQ ndi tdng tinh Scherbius
li
B0 nehich ltnr chuydn m4ch lrrdi nhrr trong hinh 4.30 thgc chdt
chlnh lnr cdu didu khidn hoAn todn hoqt dQng 6 chd alo nghich lur. Do
d6, tliQn dp Vr d phia DC cria b0 nghlch lrir niy quan hQ vdi diQn dp lddi
theo c6ng thfc:
vr=
trong
d6: ay2 - tl
36 v
lE
sd bidn 6p,
aTZ
(4.96)
"o"o
li tl
sd gitra sd vdng dAy cfia phfa n6i vdi
D1NG
ca
KDB - DtEu KHTEN r6c
oe oeNa co
KDB
L67
Ndu b6 qua diQn trd cria cudn khdng lgc La, ta cd:
V7+V1=Q
Thay (4.95) vA (4.96) vio bidu thrlc tr6n vd s6p xdp lai, la c6:
ott
"
trong d6:
a7
-aT2
-
"os,J
= -aT cosu
(4.97)
arL
aT2
Trong chC'd0 ldm viQc nghich htu, g6c kich a > g0o, do d6, d6 truot s
lu6n lu6n duong. Blng cich thay ddi gid tri cria a trong khodng 90o ddn
180o, s c6 thd thay ddi tt 0 ddn o2. N€'u a72 chQn bXng gid tri cfia drr, dQ
trudt s s6 bidn thi6n trong khoring 0 ddn 1, nghia ld t6'c dQ dQng co thay
rldi trong khoing tt tdc d0 tl6ng bQ ddn zero. Do d6, t6'c dQ dQng co cd
thd thay ddi bXng crich thay ddi g6c kfch a cria bQ nghich lrru.
Bidu thrl'c gdn dring m6 tA dic tinh cd cfia hQ thdng c6 thd suy ra
*hu sau. Ndu b6 qua tdn hao ddng tr6n r6to, c6 thd coi gAn'ddng Id c6ng
sudt tnrot sP6s bXng vdi c6ng sudt ra cfia cAu chinh hnr. Do d6, ta c6:
sP6t
hodc:
Tt
Pu,
(4.e8)
= Yo.7o
-
Y4-'Id
s
dAy suy ra mdmen tlign
M=
til
do ddng cd sinh ra:
Pa'
adb
Thay bidu thrlc (4.95) vdo bidu thrlc tr6n, suy ra:
74
}Ja vlo
= n artadU
(4.99)
Bidu thrl'c gdn tlting (4.99) cho thdy m6men dQng co sinh ra, mQt
cdch gdn dfng, tl lQ vdi ddng I7. Do thinh phdn hni co bin cria ddng
rdto tl lQ b4c nhdt v6i /a (c6ng thrlc (4.?9)), m6men dQng co sinh ra s6 tl
lQ vdi thinh phdn hii co brin cfia ddng r6to.
ttnng d.tong erta hQ thdng
Cdng thrl'c (4.99) d tr6n ld c6ng thfc gdn dring, vd ndu dtng tfnh
todn ddc tinh co cria dQng co s€ kh6ng chfnh xdc. Trong phdn ndy s6
trinh bAy cdch rft ra sd dd. tuong drrong cria hQ thdng ndi tdng vi
2- Mgah
168
V6i gizi thidt ddng /,i li6n tuc vd ph&ng, dang s6ng dbng rdto
bi6n alO cira dbng ndy c6 dang giong nhu dbng r6to trong trtrdng
tlidu khidn xung diQn trct r6to (rnuc 4.9). Giei tri hiQu dung 1,,,,, c|da
r6to, gi6 tri hdi cd bdn ddng r6to 1z tinh theo I.i duoc bi6u di6n theo
bieu
c6ng thrlc (4.78), @.7g) vd quan hQ giira chril}g bi6u di6n troDg
(4.80).
C6ng sudt diQn tir truy6n sang r6t'o dQng co Id tdng ctia: c6ng
1
(P,.,,,) vd. c6ug sudt
co (P"), cdng sudt tOu hao ddug tr6n rnach r6to
v6 lrrci qua b0 nghich luu (P,')' Nhrr v{y:
(4'
Pa, = P" + P",,,' + P,'
Tr] hinh 4.29, c6ng sudt tri vd lrrOi tinh boi c6ng thrl'c:
P, = -Vt'Ia
ThaygiritriVlvdl.Ttuorrgfngtrorrgc6rrgthrlc(4.96)vd@.79)
cdng thri'c tinh P,. o tr6n, ta c5:
p, = -
3v'/'
qTz
(4.
"o*.,
Tdn hao ddng tr6n mach r6to tinh bdi:
P",,, = 3I'r,,r",R2 + Ir12'
Thay giri tri ctia I,v tinh theo
thfc tinh P,.,,,. Lheo 1,.,,," nhu sau:
1,,,,"
Rr1
tU c6ng thrlc (4'98)' ta dudc
P",r, = 3I2r,n" (R2 + 0,5Ra)
(4.1
COng thrlc tr6n cho thdy dien tro d8ng tri ctia mach r6to
mach tdong ilrrong mQt pha ctia dQng cd ld ('Rz + 0,5.R,t)' Til cOng
(4.80), suy ra:
_z
P",u.
=
=
ttr8"+
0,5Il,r)
.J
M6men dQng co vi c6ng sudt co sinh ra do thdDh phdrr hdi co
(bac 1) ctia dbng r6to' Coug sudt truot tuong fng vdi hdi co bdn
dbng rOto ld:
Q'
sPittt = 3122 @, + 0,5R,) + P,.
trong d5: Pa11 - c6ng sudt dign til sinh ra do thdnh phdn hdi co
ca
KDB -
DEu
KHTEN
r6c oQ olt'rc co
KDB
c6ng sddt,cO sinh ra do thdnh phaD hhi cd brin cria dbng r6to:
\ '''
P"=(1 -s)Pan
(4.105)
Kdt hqp vdi bidu Lh(tc (4.L04), ta duoc:
.:
P" = [3122 (Ez + 0,5R) +
Thay gi6 lri
P,-
tt
ft_g)
\ s)
(4.106)
P,Jl:
bidu thri'c (4:101), nhArt drtoc:
(4.107)
thrl'c (4.100),
ta drloc:
",,,
=
,[*-r)tn,
uLzvvvvr
EI2cos'i =
+0'5R7,u,'-f
(+-rl(^*,
g -)
+0,5Ra )13
I
*Lt'i
='*or3 .sa
rrong
*,
d6:
2'.0,5R,1\122
[tn
+G2!o-''Rd)
s
2]*""1(4
li -Y-Jz"o'o
sarz
108)
(4'10e)
*)t,
(-2
=
\
[;-tJtn,
ro'5n7)
:
(Rz+O,lRa)
y. = l"o.o
(4'111)
@jl2)
Rr=
(4.113)
aT;2
ta nhAn
euy ddi Ldt cacrlc dai lutong phia stator vd roto,
,
(
EI2cosS=[*n*
R,_ll;,
" )-
dlddc bidu
thfc:
*()!_,1r, G.rrl)
\ s )-
R),r=ar,rz'P,,
(4.115)
R} =ar'rz'o,
(4.116
Vr=dL't'V,=Q'r"V
osq
)
A.tL7)
nh{ trinh bdy
M+ch tudng drtong mQt pha hQ thdng ndi tdrlg tinh
co
{tra ra trii vd
tr6n hinh 4.31. Dien trd ( E1 /s) dac tnnrg cho co[g sudt
.
sric diQn dOng ( V,ls) a4c trung cho c6ng sudt
vd lrrdi vA ngudn ndy lu6n cing pha vdi ddng rdto I'2.
Luu f ld trong qud trinh tinh todn dd rft ra m?ch trrdng drrong
hinh 4.31, tdn hao tr6n cdu diode vi tr6n bQ nghich htu drtoc xem
kh6ng ddng kd. Ndu kd tldn cdc tdn hao niy, lrttr y' la tai bdt k9 mot
tlidm ndo cfing c6 hai diode trong cdu chinh ltn-r vi hai SCR trong
nghich hnr d6n tliQn ttdng thdi. Do d6, ndu xem lA sgt 6p tr6n cdc
vd SCR ld nhrr nhau, tdng sr;t dp tr6n bdn linh kiQn ndy li Vp vA
tliQn dOng lr" hic nAy dugc vi61 lai nhu sau:
s6ng dbng r6to. Ngudn
V) =-orvrosr;.
+ffiu,
Htnh 4.37: Mqch tuong duong m.Qt pha hQ thtfng ndi tdng tinh
(Mq.ch tuong dtong gdn dilng)
Dfu tinh
thdng
Tt mach tudng drrong hinh 4.31:
S-
eo efio hQ
'fl
'|\
l(
*^**l';.5 | .[(r *x,\4f" = v"
r.
Ll.
lI
")
"l
ho{c: lmr+v,uf'+lnr]'
trong
d6:
* = l*r.";
t
L\
=
v'
(4.r20)
.+'l
")
(4.rzL)
,*= Y
X=Xt+
(4.119)
(4.L22)
(4.r23)
Xz
Til bidu thrlc (4.120), giai ra gid
gptta E vA. 12 nhu sau:
tri
crla dbng r6to
vi g6c lQch pha
NNa co rcoe - oEu xutEN rdc oQ o2rvo co
KDB
17L
(4.r24)
coso
=
RI'+v'u
(4.L25)
v
Vdi giri tri cho trrrdc cria s vi cx, c6 th6' tinh ra gi6 tri cia I'2 vd g6c
(4.125). Ttt
lQch pha girla ddng ndY vir E theo c:lc c6ng thfc G.L24) vd
c0ng thfc (4.L07), (4.112) va (4.113), su-v ra c6ng suat co do dQng co
linh ra:
P"
-- slISRs +v,I2f ?
= sllr'R'r*Y./;l\9
(4.126)
M6men do dQng cd sinh ra:
M=
(+,^
= ftlr;'il,
(4.r27)
+v,,I"f
sudt
Gie thidt cliQn :ip lrrdi cung cdp ld hinh sin, he sd c6ng sudt duoc
tlnh nhu sau:
4- HQ sd eOng
Hscs
'!-rrcosa t,
,
=
"6og Y4!,t"h't:,
= cong
V 'IrG 'rrr's)
sudt bidu hidn =Y
trong d6:
fl . cosor
,
= .Ir(r'.lt's)
@.1281
/r - hai co brin cria dbng diQn lrtdi;
- g6c IQch Pha gifra 7 va 7r ;
IL(,o,") - gid tri hiQu duug ctia ddug cliQn lut5'i'
c6ng thrtc (4.128) cho thdy he sd c6ng sudt ctia hQ truydn dQng c6
thd tintr to:in qua hdi co brln ctia dbng diQn lrrdi /r.. tri hiQu dqrng ciia
dbng tli6n lddi 171,,,"t vd g6c lQch pha o1. giu-a hhi co btiD cua dbng diQu
luOi va :ip ludi. Crich tinh cric dai lrrgng nay nhu sau'
Gia thidt ba pha ctia ludi vh tai lir can bhng, diQn rip pha A c6 bidu thrfc:
(4.L29)
.,[Vsin<,lt
VrrN
<D;
=
Hi[h
4.32 bidu di6n cdc thdnh phdn cua dbng diQlr troug pha A,
trongd6jr,rliddngstatordQrrgco(ddngpha),il.alddbngctiabQngh|ch
niry. Lur y
Itru trri vd lrrdi qua bidn rip. Dbng pha A li tdng ctia ciic ddng
goc
la trong hinh ndy, diQn rip pha A, 1,n", dudc lay ldm chua[ dc' tinh
lQch pha.
Hinh 4.32: Ddng sta.tor
ud,
ddng bidn dp trd ud ludi
Dbng stator dOng co, 11, lQch pha mQt g6c <D1 so vdi diQn rip pha, do
i, = Ji \
sin(ay-o1) = Ilz-ot
HAi bflc 1 cfia ddng bidn 6p trri vd lrrdi:
T, =
I"
o
arz
Nhrr v4y, hdi bac 1 cria ddng
i" =i,
hoic:
11
= arlz z-a
ludi
@,
(4.
s6 ld:
+ Ir
Z-Qy = ar Iz Z-s. + Ir Z-Ol
Tr] (4.132) c6 thd tfnh drroc gid tri hiQu dung hdi bac 1 cria ddng lrrdi
vA g6c l6ch pha gitra rip lrrdi vd hdi bdc 1 cria ddng ludi.
BAy gid, ta
tinh giri tri hi6u dung cria ddng lrrdi. Tir hinh 4.82, ta
i" = J2lrsin(rot- ot)
' - -!-4-,
arz
c6:
["-i)6]
[
*
= J2lrsin(o:r-o,),
- ["-*)=
l. 6) = ["*4')
t 6/
= Jilrsin(cor-@,) +Iatay2, (".*)= r, = (r+<D,)(4.138)
TrI bidu thrlc (4.133) c6 thd
-
I2Lft^")=
tinh
n+Ol
; o1J i"d(at)
I3
to't,
.p1
duoc
<
tri
cot
=
hiQu dung cria ddng
ludi l;:
o2xa ca xoa - otEu rcnEtt r6c oQ oQt'to co KDB
t73
TrI bidu thri'c (4.79), ta c6:
Id
arrz
7,,
arz =4%L=+
dr, - J6
J6 arz '
(4.135)
'lo
tfr^v
UiCu
ILft^s)
=
thfc
(4.135)
|
*2
vio
+i"rrl'22
(4.134 ),
ta
c6:
.lt"
+2a7lrf2cos(a-or)l
(4'136)
lt?
Thay c6c gid tri tinh dtroc tir bidu ttlftc (4.L32) vd (4.136) vdo c6ng
thrlc (4.128), ta tinh ttrrgc hO sd c6ng sudt crja he th6'ng'
5- Dd.p tng cfi.a hQ thdng ndi tdng tinh
Hinh 4.33 trinh bdy cdc quri trinh tdc dQ, mOmen vd diQn 6p khAu
trong hQ
mOt chidu khi g6c kich bO chinh lrru thyristor Id 100o vd 120o
truydn dQng ndi tdng tinh dQng co kh6ng d6ng bO r6to dAy qudn 50kW'
440V. SOHz vdi mdmen t6i blng 30Nm'
1000
950
900
q
.e 750
'oo
700
6s0
600
Thdi gian [s]
a) Tdc itQ ilQng co khi g6c hich a = 700o
40
35
Eu
920
E
o
Ets
10
5
21
23 2,4 2,5 2,6
Thdi gian, lsl
2,7
28
300
250
5
E
200
:
=
€
E
1s0
(,
C!
'6
100
c
sr
o
2
2,5
Thdl gian, [s]
c) DiQn dp kh&u m6t chidu
khi g6c kich a = 700o
1000
950
900
;850
S
soo
a 750
o
E
€
zoo
- 650
600
550
En^
2
2,9
2,1. 2,2 2,3 2,4 2,5 2,6 2,7 2,4
3
Thdi gian, [s]
d) Tdc dQ dQng co khi g6c kich a=
720o
40
35
30
E
? 25
c
o 20
E
o
=
15
10
2,1 2,2 2,3 2,4 2,5 2,6 2,7 2.8
2,9
DeNG
co
KDB -
orEu xutflN r6c o0 oQNa co KDB
175
300
- 250
a
3
I zoo
=o- 150
C)
t!
c
.OF
o
100
50
0-
fl
1'5
'
,nd' gian
2'5
3
1s1
DiQn dp khd.u mQt chidu khi gdc ki.ch a = 720o
Hinh 4.33
Hinh 4.34 trinh bdy d{c tinh co vdi cdc gi6 tri khdc nhau cta th6ng
sd didu khidn ld g6c kich a. Vdi tdc d0 ldm viQc gAn tdc d0 ddng bQ, d{c
tinh co khd crlng vd d0 dn clinh t6'c d0 la khd t6't. Vdi tdc d0 lAm viQc
thdp, d{c tinh co khd ddc vA do al6, d0 dn tlinh tdc d0 khOng tdt. Tuy
nhi6n, hQ thdng thrrdng sfi dr;ng vdi t6i lA bom hodc quat gi6, d6i tlidu
chlnh tdc tlQ thtrdng kh6ng ldn n6n rdt hidm khi lAm vigc d tdc tlQ thdp.
Lrru f ld do c6 tdn hao tr6n cdu diode chinh lur, b0 nghich lttu, cuQn
khdng lgc vd tdn hao phU g6y ra do s6ng hii dbng d r6to, d0 cring tl4c
tinh co vdi g6c kich a = 90o s6 thAp hon d0 crrng d{c tfnh cd tqr nhi6n.
r>c3>
rr,2>a1
>rl2
Hinh 4.34: Dfuc tinh co hQ ndi tdng tinh
C[ng lru y th6m ld dang ddng phfa r6to trong trrrdng hgp hQ
tdng tinh ciing gidng nhu trong hQ thdng xung diQn trd r6to kh6o sdt
muc 4.9. Do d6, khi tinh chon dQng cd, cAn tfnh d6h tdn hao phu do
hdi gdy ndn tr6n rdto, vd do d6, cAn tdng dinh md'c cfia dQng cd l6n
1Vo din}n mfc cdn thidt .
Lrru f Id trong hQ ndi tdng tinh, dd tl6m bdo chuydn m4ch cria
SCR, g6c tlidu khidn cdn duoc gidi han kh6ng vudt qud gid. trf cr-^*,
didu niy d6n ddn tdc d0 thdp nhdt cria hQ kh6ng drroc thdp hon mQt
tri cho ph6p ndo d6.
So sdnh h6 ndi tdng tinh vd hQ didu khidn diQn rip stator dQng
kh6o s6t d muc 4.4ldi sfi dung vdi tAi bom holc quat gi6:
1- He ndi tdng unh c6 hi6u sudt cao hdn hQ didu khidn di6n
stator, do trong hQ ndi tdng tinh c6ng sudt truot duoc trd vd lrrdi
vi ti6u tein tr6n cliQn trd r6to nhu trong he didu khidn tliQn 6p stator.
2- Trong hQ tlidu khidn diQn rip stator, ddng d6ng cd tdng khi tdc
giim dudi giri tri dinh'mri'c vd dat crr. c dai tai d0 trudt s = 1/3. Dd
gi6m dinh mrlc dQng co nhi6u, cd.n chon dQng co c6 dd truot dinh mrlc
cao, trong khodng O,L+O,2. Trong h€ ndi tdng tinh, vdi tAi quat
ddng diQn giillr. v6i tdc tlQ. Do d6, c6 thd chon dQng co c6 dQ tnrot dinh,
mrl'c thdp dd sfi dung trong hQ ndi tdng tinh, vd di6u ndy girip nAng cao,
hiQu sudt todn bQ h€ thdug.
3- HC sd c6ng sudt cria h0 n6i tdng tinh thdp khi tdc ilO lAm viQc
cria tlQng co gdn gi6 tri dinh mrlc .
4- HC tlidu khidn dien 6p stator srl dung vdi dQng co r6to ldng s6c,
trong khi he ndj tdng tinh sfi dung d6ng co r6to ddy qudn, ddt hon vd
ddi h6i b6o tri nhidu hon.
5- Vdn ddu trr cria hQ ndi tdng tinh cao hon nhung chi phi v4n hdnh
thdp hon.
sAl rAp cHudNG 4
Vi dq 4.1. DQng
cd kh6ng tldng bQ ba pha, ddu Y, 6 cqtc, 6OHz c6 th6ng sd
diQn dp cung cdp vd m4ch trrdng duong hinh 4.1c nhu sau:
V,=
23lY;
R, = R) =
19;
1- Ndu dQng co hoat dQng d chd ilQ hdm
X, =
tdi sinh
N, = ld2
oQt'to
co
KDB - otEu xutEN
rdc o0
co
D2NG
t77
KDB
trii ndy, vA ddi tdc dQ tudng ttns ?
Tfnh tdc d0 vd ddng dQng co vdi m6men hdm ld 1b0 Nm
2- Ndu dQng co hoat dQng I chd d0 h6m ngugc, xdc dinh m6men
mdmen
him vd ddng d t6'c dQ 1200v/ph.
Girii. T6'c dQ cldng b0: Naa = t2O f/p =
gq#
1- Trf c6ng thttc (4.2L), d chd d0 hem
o=-&1
:.lRi
+
(x, + xr)2 r/1+
fiii
= 1200v/ph; old6 = L25,7
rad,ls
sinh:
16
TrI c6ng thtc (4.22), m6men cuc dai 6 che'alO hdm tdi sinh:
u:
"
M-r*=;;-:=-Y
2aat n, _Jn?
3
+(X,+Xiy
D6i mdmen tlQng co c6 thd hoat dQng d chd
0 -+ -208,9 Nm
Tdc d0
tai tlidm m6men cuc dai:
N = (1-s) Nau = 0
-
v/ph -+
1488 v/ph
Tir cdng thrl'c (4.18)
d chd d0 ham trii sinh: M = -1bo Nm
Suy ra:
Ddtx= 1 , ta c6 phrrong trinh:
s
(l+
x)2 + 16
clQ
hdm ftli sinh:
e0,24Dx 1200 = 1488 v/ph
DAi tdc dQ hoat tlQng tudng dhg:
1200
2372
2xL25,7"1_.,/i+16 ---2o1.gNm
= -8,49x
CHUANG
t2 = -8,5 + sl = -0,5 vir s2 = -0,118
vi doan lam viec dn tlinh tr6n d{c tinh co d chd dQ hem t6i sinh
trongkhoAngs =0 + s,=-O,24, n6nchgns =-0,118' .'
V4y: rr
--
-2
Tdc tlQ tdorg
vh'
rlng:
i
N = Naa G
Dbng dQng co khi d6:
vt
I2=1"=
- s) = 1,118x
23L
*9)'+(xr+x')2
2-
6
ch6 dO hdm ngugc
1200 = L342 vlPh
111--1-;z
=27,2A
116
vdi tdc clQ 1200v/ph
N= -1200 v/Ph
D0 trrrot khi d6:
N,. -N
- =- Nat
1200-(-1200)
L2OO
V4y:
fz=
1+0,5)2 +16
=54,1 A
u = B Iz'4, - 3 54,L2 xL =84,g Nm
125,7 2
c)ab s
Trong chd t10 hdm nguoc, mdmen h6m nh6 dt dbng hdm ldn'
Vi dq a.2. DQng co kh6ng tldng b0 ba pha r6to dAy qudn 2,8kW' ddu Y' 4
cr,rc, 50Hz c6 thdng sd mach tudng drrong hinh 4'1c nhu sau:
4=2A;
Xz=3Q
Bing sau cho hai tlidm tr6n tl{c tinh trl h6a cfia tlQng cd, trong d6
hda:
didm A nxm trong vr)ng kh6ng b6o hba vi didm B: trong vr)ng bao
olCm
A
B
E (V)
80
266
I-
09
6.53
(A)
DQng co hoat dQng d chd d0 ham dQng ndng
kich til ilQc lfp vdi c6ch
co
KDB - DtEu KHTEN r6c
oQ oQtuo cd KDB
1- Tinh m6men hdm, tdc dQ, dbng rOto trrong rfng vdi hai didm A
tr€n, vdi dbng Ia= l2A.
vi
2- V6i tdc d0 cria didm B nhgn drroc 6 cdu a n6i tr6n, tinh m6men
ndu b6 qua hiQn tugng bdo hba. Sai sd tinh todn so vdi kdt quri d
a?
r. Vdi
cdch ddu hinh 4.6b, dbng df,ng
,* =#=t"=8,4s
zfif
rD6
rt=j=--
2
tri:
A
x 3' 14 x 5o
L- Vdi didm. A:
=
,!
L57
[rad' I sl
= 88,9 O
t
8,492 -0,92
-I+-2xB
= 66,8.4
88,9
Tir
cOng th(tc (4.29):
=0,21
Tdc
tlQ tlQng co:
N = (1-
s) Naa = 0,2Lx 1500 = 315 v/ph
dQng co:
TU c6ng thrlc (4.30) suy ra m6men
M
3 I7 'R"
3 8,L72 x2
= roda l-s - 157,L 0,27 =L2.tE Nrn
VdididmB: X^=
=40,74d1
' !I_ = ry
6,53
* = Izd, - I"^ - 8,492 --6,932 -''
= 2s,67 A +
"- r- &
x^
Tt
c6ng
thfc
(4.29):
uw
40,74
Iz
-- 5,07
A
Tdc d0 dQng co:
N=Q-
s) Naa = 0,038x 1500 = 57'3 v/Ph
TrI c6ng thrlc (4.30) suy ra m6men dQng co:
.
M
B Ir' '4 =
- (Dat
1- s
0,038
,l=u,2*i'
=-_?=
157
=25,8 Nrn
2- T6c dO tai tlidm B: 57,3 v/ph -t o) = 5'97 rad/s
(tinh theo tlidm
Gi6 sfi b6 qua hiQn trrong b5o hba, X* - 88'g A
mach tir (cAu 1) ld:
Sai sd so vdi kdt qui khi tinh ttdn bdo hda
5l==2?'8
xloo = 97,7o/o
e uo =
25,8
c6 thd g+p sai sd ldn
Nhrr vfy, ndu b6 qua hiQn trJQng bdo hba'
tlong n[ng'
rinh torln tldc tinh co cria tlong co trong chd d0 h6m
Y' 4 c{c" 60Hz c6 tn0',8
Vi dq a.3. DQng co kh6ng ddng b0 ba pha' ddu
mach tuong duong hinh 4'1d nhu sau:
R, = 4, = 0,O24 {2; Xt= Xz = O,l2 Cl
bidn tdn didu khidn theo
DQng co drroc cung cdp bdi mQt b0
corst. Vdi tAn sd ldm viQc / = 12 Hz' tinh:
V
lf
pnhp
1-
=
Ti sd giila mOmen crrc dai 6 tdn
sd dfnh mtlc
sd ndy vd m6men cu'c dai
&
d tdn sd niy
sd gif,a m6men khdi tlQng vl dbng r6to
sd tlinh mfc
mdmen khdi tlQng vh ddng r6to 6 tAn
0'2
Gifii. Theo c6ng thrlc (4'42): a = f lfa* =l)l$Q =
6 tdn sd f = LZ Hz vd
Theo c6ng thrlc (4'55), tl sd gifla M*
2-
1-
Tl
D2NG
co
KDB -
otEu xut€tt rdc oe oeva co
KDB
181
M^ *(o=0,2)
M^^*(a
vdi
- co:
chd do d6ng
=l)
MrYg=o'?
M^u* (o = 1)
= 0,68
Vdi chdd0 m:iy ph6t (h6m tdi sinh).
"
M^^*(a=0'2)
-',
=r'46
na;. ("
=f
2- Thay s = 1 vdo c6ng thrlc (4.84), ta tfnh duoc m6men khdi d6ng:
theo c6ng thr1c tr6n,
f = 6OHz ld:
ti
s6' girla Mna
6 tAn
sd'
f
=t2Hz vit Mp6 d tdn sd
o.o24lo.2
Mpa(o = 0,2)
Me6(a =l)
Dbng rdto khi khdi tlQng tinh tU c6ng thri'c:
r' -
Va^
a)
lt.llQLlP.zl
+(x, +x2)2
Ti sdgifra ddng r6to khi khdi d6ng tai f = l2Hz vdi ddng r6to khdi
tlQngtaif=fa^:
= 0,72
-
0'048
|
+o.z+2
0,2 )
V€iy khi kh6i clQng vdi tdn sd thdp hon dinh
m6men khdi ttQng cao hdn chd ttQ dinh mrlc vdi dbng
chd dQ dinh mrlc.
mri'c,
ta c6 thd
dat
khdi d6ng nh6 hon
Vf dlr 4.4. Vdi tlQng co nhrr d vi dg 4.3, hiy tinh tdc d0 dong co
M = Ma* vi f = 30H2. Bidt sa- = 0,04 vA dQng cd dugc cdp b0i b0
tdn di6u khidn theo quy
lu4tVlf
= corst.
Giti
q,= 3o =0.5
60
Til-iOng fh(tc (4.52) vdi M
Tai
-
Ma^
vi f = 60H2, ta c6:
f = 3,OHz, theo cOng thrlc (4.54):
Til (a) vn (b) suy ra Phrrong trinh:
Suy
ra:
Chgn s
tinh
-
-
0,98 s +1 = 0
sr = 0,089 ho{c s2 = 0,43
0,089 vi rlng vdi didm ldm viQc tr6n do4n dn tlinh cria
26,04 s2
hodc:
co.
Tdc dO d6ng bQ t4i f
=80 Hz: 60 flp
-
60130
2
-
0,089) = 820 v/ph.
Vt dq 4.5. DQng co kh6ng tldng bQ ba pha, ddu Y, 6
th6ng sd mqch tudng duong hinh 4.1b nhrt sau:
Tdc tlO clQng co: 900(1
Rt= O,4{2;
4
= 900 v/ph.
= 0,2
cu. c,
50H2, 960v/ph
Q; Xt= X; = 1,5 O,' X,, = 30 Cl
DQng co dugc cung cdp bdi mQt b0 bidn
tdn tlidu khidn theo phuong
o2ttc cd
KDB
188
4iM=0,5M6^vef-25H2;
c
tfnh
co tuydn
tinh (ld
drrdng thEng)
di€n dp khi dQng co ldm viQc d chd
00 v/ph .
a
= l2O f/p = 1000 v/ph
d/s
= 0,04
c):
+
j
1,5 = 5,22 216,7" d,
fc):
Zt = 0,4 + j1,5 = 1,55 275'Q
Tdng trd dQng co:
Zt + ( ZzZ)l( 22 + Z) = 6 Z37o
Dbng stator tlinh mfc:
Z;n =
d2
I,=4OO!J5=38,54
-6
Suy ra dbng r6to:
l,zl
z^ ,lxl, 3o x3g.s =BG.22A
l,=l
' lZ^ + Ztl
^=31,89
Sr?c tliQn dQng
dinh
mr?c:
E = Iz
189V
l";l=36,22'x'5,22=
M6men dlnh mrlc:
M^^-.3 I:R"
3
36,222 xO,2
188Nrrz
t10
1-Tai f
=25}I2+a=0,5
Thay cdc gid tri de bidt vdo (4.48), suy ra:
Md^= 3
2 ,ao
<+188=
2
3
704,7
suyras=0,0374
Tdc d0 dQng co:
Tai
N = o|,Iat(l- s) = 0,5x 1000 (1 - 0,0374) = 481,3 v/ph
f = 25 Hz, E = 0,5x 189 = 94,5 V.
Tai d6: 22 =&-+ iddt;
s
=#+
i
0,75 = S,4Z8o dl
Ndu ldy -E lim v6cto chudn (coi g6c lQch pha ctia.E
li
O"):
.,8
Io-22
=4=77,52-8'lAl
E
I^= jd(^
- 94'5
-m
7o,bx3o
Ir
Tt
dAy suy
=
=G.BZ-90'lAl
i^+ i2 = 6,g2-90" +77,52-8"
ra: /r = 19,85 A
tinh co ld dudng th8ng vdi s < s^, ta tinh nhu sau:
Tdc d0 trudt tai mdmen vd tdn sd dinh mrlc:
2- Ndu coi ddc
- s Nau = 0,04x 1000 = 4Ovlph
\h xem tldc tinh co li dudng thEng, d0 sut tdc tai M = 0,5 M6a sE
N"r
0,5xNs = 20 vlph.
T4i f = 25 Hz, t6'c d0 d6ng b0 ld: 500 v/ph.
Tit d6y suy ra tdc tlO dQng co tai M = 0,5 Ma^ vd f = 25 Hz:
N = 500v/ph - N"p = 500 - 20 = 480 v/ph
Khi tti6u khidn theo phrronC phdp ttr th6ng kh6ng ddi, ti sd E/f
gitl kh6ng ddi, suy ra tai 25 Hz, gi6 tri cria E sE ld:
E = 0,5x 189 = 94,5 V
N"t2 =
oOtta co
KDB
18b
a:
0,04
5 + j 0,75 = 5,06 28,5o, lAf
y ra:
8.72-8.5"
dn dQng dQng co kh6ng ddng bQ di6u
ich luu six-step drtoc m6 td tr6n hinh
4.35. Nguy6n If hoat tlQng cria so tld tuong tu nhrr sd tld hinh 4.22.
Chring ta s6 kh6o s6t qud d0 hic khdi tlQng dQng co theo sudn vQn tdc
duoc tllt tntdc vd ddp rlng dOng (tinh chdt dOng) cfia hQ truydn dOng khi
thay ddi v{n tdc dnt vi m6men trii theo chu k}. Dd so sdnh, chring ta
cing khrio sdt d6p rlng qud tlQ vdng hd cfia hQ truydn dgng niy.
KhAu
vn
KhAu
hiQu
tdc
chinh v4n
hi6u
Ngudn dp dc
chlnh diQn dp
KhAu hi€u
chlnh d0 truqt
Mriy phdt tdc
Hinh 4.35: HQ didu khidn udng hin
V
/f
ud hiQu chinh tdc dQ truqt
Th6ng sd cfia DCKDB: 15kW, 220V,60H2, 4 a!c, rdto ldng s6c
R1= 0,1062
dl,
Xt= 0,2745 dl
186
Ddng stator dinh mfc la 49,68 A, vQn tdc dfnh mrlc ld 17
vdng/ph, tilQ trrro.t dinh mrlc 0,0287.
MQt sd ddc tinh tinh cria dQng co drroc trinh biy tr6n hinh 4.36.
x 1oa
250
E
-4
-
200
Bg
3 tso
i
IE 100
ED
c
.O^
EZ
16
o
Jo1
=50
oc
0
ct)
0
50 100 150
VNn t6c
o0
200
rotor [radls]
300
100
3
-80
s
60
-'.6
5
3qo
sr
-20
-- 200
o
ct
U)
E',
,o
100
o
0
0
50 100 150
Vfn tdc rotor [rad/s]
200
0
0
50 100 150
200
Vfn tdc rotor [radls]
Hinh 4.36: DQc tinh tinh crta dQng co 15kW, 220V, 4 ctlc
khdi dQng vdi diQn dp
dinh mrlc, v{n tdc d{t, m6men tAi thay ddi theo trinh tg sau:
- V{n tdc d{t:
time-w=[0 0,5 4];
L- Didu khidn udng h& DCI(DB: DQng co drtgc
speed-w=[O 1 1l;
- M6men tAi:
time_m=lO 0,75 0,751,0 1,0 1,251,251,51,5 2l;
tmech-m=[0 0 -Mdm - Mdm - Mdm /2 - Mdm /2 - Mdm - Mdm 0 0 ];
Cdc cl6p rlng qu6 d0 cria dQng co trinh bAy tr6n hinh 4.37. Nhfln x6t
vd ddng stator l6c khdi dQng c6 gid tri khd cao vA sqr dao dQng cria tir
thOng stator vA r6to khi thay ddi m6men tAi.
I
oQtta cO KDB - otEu xnEr,t
I
r6c oQ D2NG cd
KDB
L87
aoo
200
Eo
o0
c
a
0
s
5-200 0
02
o
04
'! 1,2
0,6 0,8_ gian
(s)
't,4
Th0i
o
:1
It
o
o
5
E
o,s
E
on
FV
J
0'6
o'ernoi
ouu
,>.
tl
I'Itt
Eo
E
c
o
F
g-s00
,,:J
zl
s1.n (r)1'2
nttnmmu*mrmrurtflilrmluho*-,.,Jfill|llillllllllllfl,illlllil
f '7ilmn6' - -'----"",1F[|l||flflilr
0,6 0,8 1
1,2
,t,4
1,6
1,8
Thdi Oian (s)
o
€
@
6
t
o
c0
o.
o
0.6 0.8
1
Thdi gian
ct
6
8r
o
E
F
C'
<,
o
c
o
E
,=
F
o,2 0,4 0,6 0,8 1
Ttrdi gian (s)
1,2 1,4 1,6 1,8
Hlnh 4.37: Kh&i dQng DCKDB udng h& vdi
bQ
2
nghlch luv six-step
CHUdNS:
2- Di6u
khidn udng hin DCKDB theo quy luQt
z
Vlf
soo
I
S
2so
C'
oo 2oo
.(u
o)
3
1so
g
roo
!
f
F
50
-80 -60 -40
-20 0
Tdn sd
hii
20 40 60
Hinh 4.38: Dd,c ttnh
* DQng cd dugc khdi
trinh tg:
tlQng
80
co bAn, lHzl
V
lf
vdi v{n tdc dIt, m6men tdi thay ddi theo
- V4n t6'c tldt:
time_w=lO 0,5 4];
speed-w=[0 1
- Mdmen
11'
tii:
time_m=[O 0,75 0,751,0 1,0 1,25 L,25 L,5 1,5 2l;
tmech-m=lO 0 -Mdm - Mdm - Mdm /2 - Mdm /2 - Mdm - Mdm 0 0 ];
Cdc ddp fng qud d0 crria dQng co trinh bAy tr6n hinh 4.39. So sdnh
vdi trrrdng hop didu khidn vdng hd.
*
DQng cd dudc
tliiu khidn v{n tdc theo trinh
- V4n tdc dat:
time_w=[O 0,25 O,51-,O 1,251,5);
speed-w=[0 0,5 0,5 -0,5 -0,5 Ol;
- M6men t6i:
time-m=[O 4];
tmech-m=[O 0];
(1,1n
Vo
van toc p.u.
trr:
KDB - DtEu KHTEN rdc
co
DQNG
oe ootrc co
189
KDB
4
fl
q
G
.O
E
ol
rol
FAI
0,6
f
o
Dt
o'
o
c
€'
0,8
o,s
.O
E
ol
iol
F
O\
c
500
tu
1,6
1,8
1,6
18
f
o
c
eo
o
.6
c
fi
-soo
-:
500
o
o
j
't,2 1,4
Eo
-500 0
Z
looo
=E
:9^
EV
c
o
.6
-1000
:
€
600
4oo
.3 2oo
,;
I
0;
0,2 0,4 0,6 0,8
't
1,2 1,4
1
,6
1
,8
Thdi gian (s)
Hinh 4.39: Klr6i d6ng DCKDB udng hin theo quy luQt
udi b6 nghich htu six-step
V
lf
CHUANG 4,
f
o
G
!
€.
!t
o
ro
F
0,4 0,6
f
0,8
c\
1,2 1,4 1,6
1,8
D.
a
CD
c
!
(}
t'
a
o.
€F
't2
14
't,6
1,8
ro
f
ctl
c
d
CL
o
5l
o
0,4 0,6
0,8
't2
14
1,6
1,8
o,2 0,4 0,6
0,8
12
14
16
18
o ,500
6
o
qt
!
CI
0
ED
c
4
o -500
0
,5 500
c
sl
E
c
o
0
oE -s00
0
=
5 600
illth-*fi!
0,2 0,4 0,6
0,8
1,2 1,4 1,6
1,8
o 400
6
6
o
t
o 200
E
D
0
o o,2 0,4 0,6 0,8 1
1,2 1,4 1,6 1,8
2
Hlnh 4.40: Didu khidn tdc dQ DCKDB udng hin theo quy IuOt Vlf
vdi bQ ngh{ch luu six-step
D2NG
nAr
co
KDB -
ileu
KHTEN
rdc o0 oexa cd
KDB
191
rde
4.1. DCKDB ba pha rOto ldng s6c, ddu Y, c6 c6c th0ng s6'dinh mric:
37,3kW, a60V (dp ddy), 60H2, 1180v/p, sd crJ.c: 6. Th6ng sd cria mach
ttrdng duong gdn dring cria dQng co (hinh a.l(d)):
Rr = 0,19C2,' Xt=0,75C2; X^=20C2; Rz =O,07dr;
Tinh:
tz
= 0,380
a) Dbng stator, m6men, hO sd c6ng sudt vd hiQu sudt d6ng co vdi
trii
dinh mrlc.
b) Ti l9 m6men khdi rlQng/m6men dinh mric vd
tl
lQ ddng khdi
d6ng/ddng tlinh mrl'c.
c)
Tl le m6men mayJm6men dinh mf'c
4.2. DQng co c6 thdng sd nhu d bai 4.1 drroc sfi dung trong chd d0 h6m
sinh vdi ngudn cung cdp ld dinh mfc. Tinh:
tdi
a) Ddi mdmen hdm d6ng co c6 thd sinh ra vd ddi t6'c d0 trrong rtng.
b) C6ng sudt ham tdi da c6 thd sinh ra
c) Tdc d0 dQng co
tai mdmen hdm 300N.
4.3. DQng co c6 thdng sd nhu 6 bei 4.1 dang hoat dQng vdi tdc tlQ dinh mfc
vd ngudn cung cdp ld tlinh mri'c thi hai trong ba pha ngudn drroc tl6o
vdi nhau.
86 qua qudn tinh tliQn til, didm ldm vi6c ban ddu cria dQng co khi
'
ngudn tl6o chidu s6 d chd d0 Ci ?
Tinh m6men vd ddng dQng co tai didm ndy.
4.4. DOng cd kh6ng ddng
rdto dAy qudn, ddu Y: P6^= 2,8kW, (Jd^ = 4O0V;
f = 50H2, sd tl6i crr.c = 2, rld^ - L37Ov/p, c6 th6ng sd mach tudng
drrong: Rt = L,9dl; Ez = 4,575d1; X, = Xe = 3(.2
bO
Ddc tinh tt h6a cria dQng co do d chd tlQ kh6ng tdi vdi t6'c dO gdn
blng ddng bQ cho trong bring sau:
0.'t3
0.37
061
09
't 22
171
2.24
't2,1
EfiN
31,8
54
80
108
143
173
I. (A)
Eff)
2.86
199
3.86
226
4.90
246
6,53
266
8.16
281
192
4.5. DOng co 6 bdi 4.4 drroc didu khidn bing crich th6m diQn trd phu
pha tldi xwrg vdo rdto. Ti sd vbng dAy stator/rdto ld 4,25. 86 qua
trl h6a, tdn hao l6i vi tdn hao do ma s6t vd qu4t 96.
a) CAn th6m diQn trd phu ld bao nhi6u dd dQng co hoat d6ng vdi
dinh mfc d 400v/p.
b) Cdn th6m cliQn trd phu ld bao nhi6u dd dOng cd hoat rtQng d
d0 ham ngugc d tdc d0 dinh mrlc vdi m6men crr. c dai.
4.6. DOng cd A bei 4.4 dugc tlidu khidn blng c6ch thay rtdi rliQn rip
cdp cho stator. Gia thidt tAi ctia dQng co ld dinh mrlc vdi tdc dO
tlinh mrlc. 86 qua dbng tU h6a, tdn hao l6i vh tdn hao do ma s6t v&
quat gi6.
a) Ndu mdmen tai ti le thuQn vdi tdc dQ, tfnh diQn dp cdn cung
cho stator dd tdc tlQ la 0,5 tlinh mfc. Tinh ddng stator khi d6.
DQng co c6 thd hoat dQng dn dinh tai tdc d0 ndy kh6ng.
b) Ldm lai cAu a v6i LAi ldc ndy
tl
lQ
thufn vdi binh phuong
t6'c d0.
4.7. DQng co khOng ddng b0 ba pha 460V, 6OHz, 4 cr1c, ddu Y c6 cdc tham
sd ,R1 = 1,01Q, lq = 0,690 , Xr = L,3C2, X; = 7,94d2, X* = 43,5d1. Tdn
thdt khOng tei b6 qua. M6men tii ti le binh phrrong vfn tdc vd c6 gid
41 Nm 6 v4n tdc 7740 vglph. Ndu nhu vQn tdc d6ng co ld
tri Ii
vglph, hdy xr4c dinh:
a) Mdmen tAi Mt;
b) Dbng r6to 12;
c) Dien rip ngudn cdp cho stator V;
d) Ddng ng6 vdo tlQng co .I1;
s-
fng vdi dbng .I, crr. c dai;
f) Dbng r6to cr,rc dai /2 max;
g) V{n tdc dQng cd khi ddng .I2 max;
h) M6men dQng co khi dbng -I, max.
e) V4n tdc trrrot
4.8. DQng cd kh6ng tldng bQ ba pha 11,2 kW, l75ovg/ph,460v, 6OHz,
4 ct!c, ddu Y c6 cdc tham sd Rr = 0,660, 4, = 0,38C), Xr = 7,L4C2,
Xz = I,7Ldr, X^= 33,2t . DQng co drroc didu khidn theo quy ludt Vlf
vdi ti sd V lf = Va^lfa*= const.
a) Tinh gid tri m6men crtc dai M^* vA. tlQ trudt tdi han <q" khi tAn
G CO
55 Nm, hdy xdc dinh:
KDB
193
.8 drroc didu khidn bdi bO nghich lrru
ugc grt khOng ddi vh blng 20A. Tdn
sd ld 40Hz vA. m6men dQng co li
a) D0 trudt tdi han s- rftrg vdi m6men cuc dai M^ va gid
cuc dai ndy;
tri m6men
b) D0 trudt s;
c) V4n tdc dQng cd o;
d) Dien dp pha cdp cho dQng co V;
e) He sd c0ng sudt PF.
4.10. DQng cd khdng ddng bQ ba pha 460V, 6OHz,6 cgc, ddu y,
r6to ddy
qu6ir vdi vfn t6'c drroc di6u khidn theo c0ng sudt trrrot theo so
dd hinh
4.25. Tham sd dQng co: R1 = 0,041C), Rz = 0,044C), Xr 0,290,
=
Xz = O,44dl, X^ = 6,1C1. Ti s6. vdng ddy cuQn stator vd r6to la UO,g.
Cim khdng L4 rdt ldn vd dbng I ph8ng. Gi:i td cfia R1, Rz, Xr vd. X2
cho mach tudng duong c6 thd b6 qua so vdi tdng trd. hiQu dung c(ra L,.
Tdn thdt kh6ng tei b6 qua. Tdn thdt chinh lmr, cuQn La vdbQ chopper
dr)ng GTo b6 qua' M6men tei tt 16 binh phrrong van t6c c6 gi,i td
750Nm 6 L775vg/ph.
a) Ndu nhrr dQng co vQn hanh vdi v6n tdc nh6 nhdt ld gO0vg/ph,
xric
dinh diQn tru R. Vdi gid tri .R ndy, ndu y6u cdu v{n .tdc ld
1050vg/ph, tinh:
b) Dbng qua cuQn cLmIa;
c) Tt s6 cl6ng bQ chopper 14
d) Tri trung binh diQn dp ng6 ra bQ chinh lrru Va;
e) HiQu sudt;
d) HC sd c6ng sudt ngu6n.
4.1r. DCKDB trong bai 4.10 duoc didu khidn bxng h6 truydn dQng Kramer
nhrr tr6n hinh 4.30. Tl sd m6y bidn dp ld. a72= 0,9. M6men tai d le
binh phrrorg van tdc vi c6 gt6 tri zbONm d 10s0 vglph. 86 qua cdc
tdn thdt. finh:
a) Tri trung binh dbng ng6 ra bQ chtnh lrnr
^t4;
b) Tri trung binh di6n dp ng6 ra bQ chlnh htu Va;
c) G6c tlidu khidn bQ chtnh lrnr cr;
Chl/;ong
DGu KHtfN vEcrd oOnc Gd
KH0NG odNc e0
s.t
wtO n'iruH
sQttc c0n sqt'tc cd KH0NG sdHc e0
pha t16 drrgc dd
So tl6 tLldng duong ctia dQng co kh6ng ddng bQ ba
c{ptrongchuong4choph6ptinhtodncdcdailrrongcobAnnhuddng
hdnh d x6c l{p' vdi
stator, he sd cdng sudt, m6men"' khi tlQng cd van
So dd
v{n t6'c cd dinh vd nguiin rip cung cdp c6 dang sin v?r cAn bhng'
niykh6ngtnriar:ngtltldckhiphAntichtrangth6iv$nhdnhqu6dQciia
ngudn tt mQt bO bidn tldi
dQng co, th6m vdo d6 khi dQng co dugc cdp
c6ng sudt.
co trong hQ truc toa
Phdn ndy trinh bdy v6 mO hinh dQng cria dQng
d0tinhstatorvdhQtructoadQquayr6todrratr6nkh6ini€mvdcricd?i
ph6p phdn tich
dQng cho
lugng v6cto ciia mriy diQ" xoay chi6u' M6 hinh
lan xric l{p vh khi tlong co drroc
r14c tintr cria dQng co 6 chd clo qu6 tlo
cdp tU mQt ngudn 6P c6 dang bdt ky'
(Gf)
7- VOcto hh\ng gion trong hQ tgo dQ tinh stotor
kh6ng tldng
Hinh b.1 trinf iay m4t c{t crla stator cia mQt tlQng co
sdt gid srt cuQn stator m6i
b0 ba pha hai cgc. Dd tlon gian cho viQc khao
(trgc hoAnh) vir truc 0 (truc
pt,a cr,i gdm mQt vbng day' Hai trgc: trgc a
tlrroc goi ld hQ trgc tqa dQ
tung) g{n vdi m{t c6-t stator nhtt tren hinh
tinh stator.
hc thdng diQn 6p
Ddu ti6n gi6 srl cuQn stator dUgc cdp ngudn tir
trinh bdy gi6n
5.1
g6c <0" ' Hinh
xoay chi6u ba pha can b'hng vdi tdn sd
tldu cD"f = 0o. Dbng io", i6", i",
a6 vOctO dbng stator I*,16",I," A thdi tlidm
tlQt'g F^'Fa"''[* la ciic
trong cdc cuQn ddy AA', BB', CC' sinh ra luc tU
KHTEN
vEcra sQne co rcuOua o6Na eQ
195
d.|ng (mrnfl & t4t = 0o
Hinh 5.2 trinh bAy trudng hop cdc v6cto pha ddng quay tli mQt g6c
600 (nghia Ii sau thdi tlidm dAu,1/6 chu ki).C6 thd nh4n x6t rlng v6cto
tdng F,' dd quay di mQtr g6c 600 trong hQ trUc tqa tlQ stator (h0 crp). Bi0n dQ
Hinh 5.7: Vdcto lW
cria v6cto
ttX
ndy git nguyOn, l6n hcrn 1.5 ldn so vdi v6cto lrrc
tt
dQng c6c pha.
:p
I
lvc ttl d1ng (rnmf) & c4t = 60o
Cdn chri f rlng cdc d4i lrro,ng v6ctd xudt hiqn trong khOng gian vQt
thqtc cria dQng cd, trong khi c6c v6cto pha ln bidu di6n c6c dai lrrong
trons h0 truc toa d0 phfc trrdng tr/Ong. Vi vdv,
HJnh 5.2: Vdcto
lf
g6c hinh hgc 0" chl blng g6c diQn ort cho trudng hop stator hai
(p = 1). MQt cdch tdng qurit cho stator cd p sd ddi crrc:
o"
=q
p
(s.
Chon truc a lA truc thuc vd p ld truc 6o, v6cto
F,'dugc bidu di6n nhu sau:
lrr.
c tir d6ng td
F"'=F"rit,=F'+ jFi
C6 thd thdy rXng cdch
bidu di6n d?ng v6ctd nAy
mang tfnh tdng qu:it hon so
vdi bidu di6n cdc Clai lrrong
drrdi dang v6cto pha, nhdt ld
trong cdc trrrdng hop ddng
stator kh6ng c6 dang sin vd
kh6ng cdn blng gifra cdc pha.
Trong tnrdng hop ddng xoay
chidu ba pha cAn bhng vd sin,
d trang thdi xric l6p, v6cto
41"6 bi6n d0 kh6ng ddi va
F;
Hinh 5.3: Cdc thdnh phdn cila l4tc ttt
dQng trong hQ tr4tc toa d6 stator
quay vdi v{n tdc ro tuong rftrg vdi tAn sd ngudn cung cdp. Trong cdc
trrrdng hop kh6c, v6cto ^ff c6 bi6n d9 vA vfln t6'c quay thay ddi vi phu
tri ddng stator.
Do v6cto F,' la tdng cdcv6cto F,",Fo,,1,trong h6 truc toa dQ ap,
cdc vdcto ndy vu6ng g6c vdi mnt phEng cdc cuQn dAy stator d{t lech
thu6c vdo cdc gi6
nhau 120o trong kh6ng gian n6n dang gi6i tich c6 thd bidu di6n nhrr sau:
F; = P^"i0" * F6"ei12o' + F""ei24o'
(5.3)
Kh6i niQm vd v6cto kh6ng gian c6 thd md rQng cho cdc dai lrrgng
khric cfia dQng co nhrr dbng di6n, diQn 6p, tt th0ng.
V6cto kh6ng gian ddng stator:
/""
- Is eil" + If"eir2o" + I!"ei2+0'
(5.4)
V6cto kh6ng gian diQn 6p stator:
i;
=Y" nio' +Vf"eir2o' *Ys
"i24o'
(5.5)
=_-Z
oEu rcnErv vEcro o2Na ca xuONo o6Na
aQ
197
* @f"s"r120" + Oler2ao"
(5.6)
V6cto khdng gian til thdng stator:
@! = @s s"ro
C:ic dai lugng rdto drroc bidu di6n trong h0 aF phrl'c tap hon do bdn
thAn r6to quay trong hQ truc toa dQ stator. Quan h9 girla vfn tdc tnlot,
vAn tdc rdto vd v6n tdc tldng b0 nhu sau:
(5.7)
0"1 *01 =(r)"
C:ic itqi lrrgng r6to quy vd stator: (v6i
a71=f
"U
,= #,
i:={ii
aTt
(5.8)
ul = a7'ejouf,
(5.e)
@f, =
arfjsQi
2- PhOp ehuydn d.di abe
+
(5.10)
q|vd. ap -s abc:
Tridn khai cho v6cto ddng:
ij
= L" fcos(0')+7'sin(tr )]*,0" [cos(rZO')+7sin(120')]
j
+ i""
fcos (240') + sin (240e)]
. 1. 1. .(,fs. J5. )
=t*-Etb"-
rr""*tlrro"-
2r""
(5.11)
)
=,i'+jd"
Nhrr vfly:
_,1
2
I
J5
L
(5.r2)
2
Do
i,
Ta duoc ma trQn
c8
=Q
a
lor
ii abc
1
I
-,
I
J5
I
(5.13)
(5.L4)
Ph6p chuydn ddi ngrrgc
crp
+
?
3
abc:
0
1
1
3
{3
1
1
3
v3
2
3
_1
hodc:
3- Phttotrg
trinh
0
I
3
{3
1
1
3
JE
d.p vd d.bng
trong
hQ tgo dQ, aF
!R
Hlnh 5.4: Mach diQn twng dwng RL cho cuQn stator ud r6to
Phrrong trinh diQn 6p stator:
uj=Eijl,#
cho rdto:
,f,=Wii-#
Diqn tid r6to quy ddi:
n;=\n,
tLtt
Til phuong trinh (5.8) vA (5.19) thay vAo (5.18):
otEu xurEN
vEcro o2r'to co
KHONG o6r{o aQ
199
Thdnh phdn thrl hai trong (5.18) tU (5.10):
dqi
dt=af4.")
dtl%r , )
_ t (ae_io o: * dgi r_r" l
arrl dt '
dt
L
=o.tf("-*d(-is)-.,
dt
vi
do:
)
* dol
d, "-;,l)
d0
6.22)
:=G)
dt
da:
n€n:
(5.2L)
"-i'(
aa:
-'*
E= urla'
D:
l
(5.23)
)
vio (5.18):
d?i
u", = R,i)*
dt -rro;
dua vdo t6an t& Laplace p = dldt:
uj = R"jj +po:
ui =R,i", +(p- jar)oj
cudi cing, thay (5.20) vd (5.23)
V6cto tit th6ng c6 thd drrgc bidu di6n theo
cfuc
(5.24)
(5.25)
(5.26)
v6cto dbng diQn nhrl sau:
i;;l=[,i ?]t;l
vdi
L-
(5.27)
- diQn c6m h6 hldng;
L" - diQn c6m stator: tdng cia diQn cdm tdn cria cuQn stator Z6 vd
diOn cAm Z-;
Z, - diQn cdm r6to: tdng cria diQn cim tdn cria cuQn r6to L6 vi
diOn cAm Z-.
Thay (5.27) vdo (5.25) vA (5.26) ta drrgc ma tr{n phrrong trinh diQn 6p:
f,;l=f.&ir."_"
!L^,llrl
- ia\L^ R, +(p- iro)r"JLi;l
Lr;l
l@
6.28)
Phrrong trinh (5.28) khdng thich hop cho cdc mO ph6ng tl4c tinh
dQng ding mdy tinh sd, n6n cdn mQt sd bidn tldi trung gian. Tridn khai
cdc v6cto diQn dp theo cdc thinh phdn crp cria chfng:
(5.
(5.3
(5.34)
hodc:
o o o ,; L" o L^ o f,i,
f'a' 1-&
dldd,
lrd" =l o n. o o d" r' o r," o L^'arli:0
&n,
R"
oL,
L,n
0
L,
O
iL.
lr; |
o
R,
0
L^
o
L,
-lrL,
L-a/-^
L+
d,
Lf'
L,o-L^ou;"
O L" O -L^
d"
-L^0L"0r"
o -L^ 0 L"
"d,
vdi:
r"
=Jd-zr*
-t
xnEx vEcro ooNe co KHING o6Na e6
otEu
207
Phtong trinh m6m.en
Trong dQng co hai pha don giin, cu6n stator ba pha cria dQng co ba
pha thrrc drroc thay thd bdi hai cuQn dAy tinh vu6ng g6c. Dd phdn tich,
c6 thd xem v6ctd quay luc tr} dQng .ff arrg" tao ra bdi mdt cuQn dAy gi6
tudng quay vdi v{n tdc g6c trl,. Tuong tU, cdc v6cto r6to li6n quan ddn
m6t cuQn ddy giA tudng kh:ic cfing quay vdi cirng vrin tdc ar.. CuQn stator
vd rdto gi6 tudng tii dbng stator i" vd rdto i. trong hQ truc toa d6 ap nhu
tr6n hinh 5.5. Cdc cuQn dAy c6 sd vbng dAy blng 1, vi thd
4" = {" ve 4 = i: .Hai v6cto dbng lQch nhau trong kh6ng gian mQt g6c
6. Czic dudng chdm chdm ld drrdng sfc cria tt th6ng stator <D,". B:in kinh
ciia cu6n r6to ld r.
4-
p
I
I
:
I
Hinh 5.5: M6 ltinlt cuQn stator
ud' rOto quay
Lrrc diQn dQng sinh ra trong m6i cuQn r6to vu6ng g6c vdi drrdng sri'c
tir th6ng. Thdnh phdn lrrc F sinh ra mdrnen sE vu6ng g6c v6i drrdng
cia
kinh
cuQn dAy
vd duoc tinh bdi:
F = Ftsin(6)
vi:
F1 =
M6men:
Br"li,
M' =2rB,rli, sin(6)
Mat d0 tU th6ng:
(5.38)
(5.39)
(5.40)
Thay (5.41) vdo (5.40):
M'=(Drrirsin(6)
Til
th6ng:
(Dn =
L^i"
Bidu di6n g6c 6 theo cdc thdnh phdn ddng:
f,/inh 5.6: Cdc udcto kh6ng gian ddng trong hQ trtl'c tga dQ aF
sin(S) = sin(6, - 6" )
= sin(6" )cos(6.
)-
cos (6"
a6"
=-6"iil
i, i" -i,
i" --=*(at
l"l" ''
Thay (5.43) vn (5'44) vAo (5.42):
M' = L^(d"*
)sin (6, )
(
-ed")
-Ad,)
(
Tirn mdi li6n quan vdi m6men thu. c (do bi6n d0 v6ctd kh6ng
ldn hon 1.5 ldn bi6n d0 dai lrrgng pha):
Ta c6 mO hinh cuQn ddy chl c6 mgt vbng d6y:
(5.
% =4 =1'5/"^"* =L'5'f2I'
u" = 1'5'f2V"
S"
='"L
=4'5V"1"
S" = 3%/"
(5.
Thay (5.41) vio (5.40):
M'=Q,"irsin(S)
TU
th6ng:
(Dr,
=
L^i"
Bidu di5n g6c 6 theo cdc thAnh phdn dbng:
.s
laS
Hinh 5.6: Cdc udcto kh6ng gian ddng trong hA ffVc
sin (S) = sin (6"
-
-
6" )
sin(6" )cos(6. )-cos(6")sin(6t
=d".;;-;&.d"
i" i, i" i,
-,td,)
=*(rd"t
l"L, '
'
Thay (5.43) vd (5.44) vdo (5.42):
M' = L^(t"A
-,;A)
Tirn mdi li6n quan vdi m6men thrr. c (do bi6n
ldn hon 1.5 ldn bi6n d0 dai lrrgng pha):
Ta c6 m6 hinh cuQn dAy chl c6 mQt vbng dAy:
h = 4 = 1'5/"-"* =L'5^f2I s
u" =L'5'12V"
S"
='"L =4'5VJ'
s" = 3%/"
tgl
tlQ
Thay (5.41) vdo (5'40):
M' --@"rirsin(6)
Til
thdng:
(0,, = L^i"
phdn dbng:
Bidu di6n g6c 6 theo c6c thdnh
.9
.s
lo,
gian d'dng trong hQ trryc tga dQ aF
Hinh 5.6: Cdc uicto kh6ng
sin(S)=sin(6, -6")
=
sin(6, )cos(6. )- cos(6")sin (6' )
A--tt-
6"-
=6"i" i,
is
=l(6,e
ItL, ''
-&td")
(5'42):
ThaY (5.43) vd (5'44) vdo
M' = L^(6,,;
t,?
(
-l}d")
(do bi6n
Tirn mdi li6n quan vdi mdmen thr'tc
pha):
ldn hon 1.5 lln bi6n dO dai lrrgng
mQt vbng dAy:
Ta c6 m6 hinh cuQn ddy chl c6
L=4=1,5f"."*
(l
dO v6cto kh6ng
=L,5.f21"
(
v" =L,5.f2V"
S" = r"L =4-5V"I"
ss = 3%/s
(
(5.
r
otEu xutEN
vEcro
co
DONG
KHoNc cr,NG Ba
lh:
Nhu vfY, mdmen cfia dQng co thdc
ho{c:
5- Mgch d.iQn
P.f,u'
=
M
=Z'P'z- tm(ii;i')
tttotg dwng
(5.50)
=! n u(4"'; -,td")
M
mO
(5.51)
hinh dQng
Phrrcrngtdnh(5.27),(5.28)c6thdtlrro.cvidtchodOngcor6toldngs6c:
{5'52)
o: =4t;
+L^ii
ai
+Lrii
= L^i'"
(5.53)
(5.54)
ui = a,ij +Po:
I
(5.55)
o=R.il +Poi -7cooi
(5.56)
L"=L1"+L^
vl
(5.57)
Lr=Lu*L^
+;;)
(5.58)
ai =Lt,i: +Z- (;; +;;)
(5.5e)
O: = Z,"i: +Z- (;;
n6n:
trinh (5'54), (5'55)' (5'57)' (5'58) m6 ti
cria DCKDB'
tr6n hinh 5.7, dic trrrng m6 hinh dQng
C6c phrrong
Rs
-€*
Lr,
Lfl-q
so tld mach diQn
R,
l,:
L.
tuong duong
Hinh 5.7: M6 hinh (rng'ch diQn) dQnS
crta ilQng co hh1ng d6ng
DQ
bQ
trugt:
o:l
s
(5.60)
"=6
tliOn 6p pha:
i
u",
Phuong
trinh
=7,5JjY""j'"t
(5.27) vd (g.2gy c6 thd drroc vi6.t
lai nhu sau:
15rf2rir"ero+t = l,}J-2Lt"i
+ Z^ (t,s,ldj
+ t,1J-zi
"ei'"'
""i^",
"ei'", )
i
L, 5J-26, ei' "t = l, 5 J-2 h, i, ei' ", + r (t,sJd i,e %t + l,s.!-z i, e i, J
_
)
L,
5J-2v ei wt = L,sJd R
"
o = !, 5 J-2 R, i,
chd
f
i
"
e
i, "t +
i *r
""
fi f
,s
*
*t(t,
J zo, i *,
"
s.,E
_
)
ir" e.r."
r
i
(5.
(5.64)
)
i \ ;J-2,rfr i, ",
"
(5.65)
"
la:
dt
fi (,sJia,";+t
d.r
fr (t,sJ-za,".r''"
b.Eor"<ir"e/'"'
) = "r1,
t
)=
i t, 5J-2a"6 ei,"t
"
Rrit gon cdc phuong trinh (b.62) - (b.65):
.ir"=Z^i"
6"
+L^(i"+Ir)
(5.68)
=Lpi,+z^(i"+i,)
(5.6e)
% = R"i" +Jo"6"
O
Phuong
trinh
=
R,i,+J(ol"
(5.70)
-r).t,
6.71)
(5.71) trrong drrong (blng cdch nhdn hai v6. vdi
#*ol + 7o"6" = f i
+7or"<ir" = g
9)'
0sl
(5.72)
M6men dQng co d trang thdi xdc l{p:
M =B.p.L^rm(i"i;)
Phuong
trinh
(5.68) vn (b.21) c6 thd bidu di6n drrdi dang ma trQn:
Lo
+j<o"a
oja"L^ llt"I
J-l i.'"r.^ g.;'"allr.J
lu"I = f&
Cdc phuong
(5.73)
(5.74)
trinh (5.74) m6 tA so dd mach diQn tr6n hinh b.g,
trung m6 hinh cria DCKDB d trang thdi xdc l6p.
d4c
otEu xutEN vECTo oQNc
I"
._-,-
co xu1Ne o6ua a6
205
Rs
l',
Hinh
5.8: M6 ltiruh htach, dtAn) xclc
ldp tilortg duong
ctia d6ng co lelt|ng d6ng b6
' 6- PhOp bidn ddi trong hQ tpa dQ roay (tt.A tuo cl6 kictt
Phrrong trinh (5.61) c6 thd vidt dudi dang:
u,"r"
+ 7ufi" = r, 5J-2v
vdi J2 V" vd <p" ld bi6n ctQ vd g6c pha
"si1
(
cria v6cto pha
ui" = f,SJ2V" cos(or"f
dq)
(5.75)
"ei'tp",it'';.r
= t, |J-2v"cos ( t,r"l + q" ) + j 7,5'{tV
Do vdy:
ti
or"f + tp" )
t.
+ q" )
(5.76)
u[" = r,5J2V" sin(o-r,/ + qr, )
(5.77)
\n thd, trong cric diiiri ki6n vAn hdnh xric IAp, cric thdnh phAn cr B
j
i
i
ctia cric dai luqng v6ctd kh6ng gian c6 dang xoay chidu. Cric dai ltrgng
xoay chi6u thrrdng kh6ng thich hop cho ciic h6 th6iig dieu khi6n (thLtdng
dnng cric bidn dang tin hi6u DC thay d6i theo thdi gian), vi vAy mOt
ph6p bidn hinh khric sE drloc drla vdo nhhm chuyen d6i czic thdnh phAn
xoay chi6u cr B thdnh cric bidn rn6t chi6u.
HQ truc toa clQ xoay (he truc toa d6 kich tir) dq drroc dinh nghla d
dAy ld hO truc toa dQ sd xoay vdi vdn t6c g6c co" cDng chi6u vdi v6cto
mmf {'. K€t quri ld o xric lAp, toa dQ ctia cdc vecto kh6ng gian ctia
tlQng co trong hQ truc toa dQ mdi dq s6 c6 giri
gian (xem hinh 5.9 vi 5.10).
tri
kh6ng d6i theo thdi
CHUONO
ol=0
od
Hinh 5.9: Vdcto rnmf stator trong hQ tr4rc tga d6 tinh
ud. roay d thdi didrn dd.u
a
otEu xurEN
vEcro
oQt'to
cd xuONa o6va e0
207
M6'i li6n quan gif,a v6cto diQn dp trong hQ tqa tlQ aF vd dq:
uj = PfsJo"r
(5.78)
uf = ujs-"roJ
(5.7e)
Phdn tich phuong trinh (5.79):
v"6s
+ ju"ns =
(rt
*iri")[cos(-or"t)+ jsin(-or"r)]
= ui" cos (q r)* ri, sin (o:"f )+
j[-r;"
sin
(5.80)
(co"
t)+
q"" cos (ro"
r)]
Suy ra ph6p chuydn rldi cp -> dq:
'l
ri,
lr;r = | cos (or"t) .* 1<,r"r;'lf I
Lr;r.J l-sin(ar"/) cos(o"r)Jfufi"l
vd ngrrgc
(5.81)
lai dq -> aF:
fr; I _- fcos(co"r) -sin(or"r)lfuls l
j lsin(o"/) cos(rrr"f) JLr;"J
Lrfi"
(5.82)
Phtong trinh d.Qng cd trong hQ tgo dO dq
Phrrong trinh (5.17) c6 thd bidu di6n drrdi dang:
7-
u"reit"t = R"i", ei%t +
vdi:
(5.83)
p(berei@"t
(5.84)
=d*3 "i'"' +Tol"epJo! =(p+7co")Q!er4t
Thay (5.83) vdo (5.84) vi rdt ggn:
u! =^R"{ +(p+ jo")ol
p[""ei'J
Phrrong
trinh
(5.85) c6 thd dat drroc
tir (5.23) ndu thay
(5.85)
p
+ p + jo\
Tuong tg cho phrrong trinh (5.26):
uh = R,i3
do
+(p+ ja"-jo)o1= R,ii +Q+ jorg)ofi
(5.86)
4t;
(5.87)
cb"r=L^i""+Lril
(5.88)
A"" = L"i", +
(5.8e)
ho{c
(5.e0)
Phrrong
trinh
m6men:
M=?.p.'-
B
r
l'c'e
'o'P \ 2
t,,linsiita-ii1si'rn)=i
o'2,,I,,,(ti
*\
,i J
tS,t
Vi dq 5.f. Cho d6ng co c6 tham sd nhrJ sau:
Ba pha, ddu Y, d6ng co kh6ng ddng b6 r6t,o ldng s6c, 7,46 k
220V, 60H2, 1164v/ph, s0 d6i cLrc p - 3
R" = 0,294e\ Xt" = 0,524Q; R,. = 0,156fJi Xr, = O,27ge; X,, IE,4E7C)
=
M6men quein tiuh r6to J = 0,4 kg.m2
D6ng co van hdnh d tra'g thrii xrlc lap vd'i cric th6ng sd di'h md,c,
}ldy x6,c dinh cric v6cto pha dbng stator, r6to vd rn6rneu d6ug co blng
hai ctich:
a) Girii mach di6n trrong duong m6t pha ci trang
b) Sri dung cdc phuong trinh (5.78) vd (5.24).
thdi xdc lAp
Girii. VAn tdc ddng bQ a, = 2rcf = lv x 60 = B77radls.
a) d trang thrii xric lap mach di6n trrong duong m6t pha ctia tlQng
co nhu tr6n hinh 5.8. Di6n dp pha ugu6n c6 giti tr.i:
t, =ry=r27v
vo
Tdng tro tuong duong cria mach:
2
= o,zg+ +
j0,524.
i?:t!!
I!,!1_!F:'-)
= 5,335t25.5"t)
jL5,457
+5,2+ j0,279
Nhuv4y, cric v6cto pha dbng i" vit i,. duoc
T/
I"
i,
z
=
t27
5,335t25,5"
=23.8t-25.5A
,== .=j-tu=n!' .=
=22,21772,8"A
-i" j75,427
+5.2- j0,279
==^
C6ng sudt di6n trl cd'p cho r6to:
D
Pa,
xeic
= 3I? "r
s
=
B
"(ZZ,Z)2
xE,2 =76ggw
C6ng sudt co:
P"u=Pdt- 3I?R,=7457W
VQn t6'c g6c cria rdto:
dinh nhu sau:
r
otEu xurEN vEcro oQNa co xuOua o6No a6
209
Suy ra:
e81
fil-
Lli-
tzzf
o
J
%l_
=
77
l-
TU (5.73)
M = 3' p'L^t- (r"r".)
= 195sin(-l98, g9 =
= 3x 3x 0,04
txlm(28,82-28,s.x22,22 -772,g")
6I.2Nm
c6 thd nhan x6t thdy hai crich gi6i cho cdc kdt qu6 nhrl nhau.
vi dq 5.2. sf dung phrrong trinh (b.2s) dd x6c diuh c:ic v6cto kh6ng gian
dbng stator va. r6to trong h6 truc toa d0 tinh stator crB. Tinh
mOme' cfia
ddng co trong c6c didu ki6n vdn hAnh nhu vi du b.1.
Girii. Cric gi'a
tri di6n cdm cria dQng co:
z"- =&= tu:99t =o,o424H
ol" 377
L,'
tu:ltu
=L-=
o)s 377 =o,o4t7H
L^
=
I---o
15-45?
377
= o,o4LH
Tdc d0 dQng co:
=.(1 - s)o" = (1 - 0,08)x 877 = 86.8,7 radJs
V6cto diQn :lp stator duoc tinh tir c6ng thric (5.61):
or
Tir phrrong trinh (5.28):
f z6g.+"it rrl
o
I
.]=
I
o,zs++0,0424p 0,04Lp
L(o-;tub,z)0,041
0,156+
li,""l
(p- i365,7)o,onlzll;'l
Do dQng co vSn hinh d xdc l4p, cdc v6cto dbng s6 quay vdi v{n
g6c kh6ng tldi ars vdi bi6n d0 kh6ng ddi. \n thd ta c6:
ii
= f"sj(377t*6")
;s
-
7r"i(377t+6,)
Todn ttt p trong phuong trinh c6 thd thay blng jar.= j377, v\
pr; = 4'7""i(stzr+6") = i'g77'
vd
= ig77i:
1,"i(377t*6")
dt"
Pii = i377ii
Sau
khi thay vdo phrrong trinh ma trQn tr€n, ta
1269,4"iit"'l -
[;; I -
fo,zo++i15,981 iL5,457 lft:l
o l-L i0,463 0,156+jo,4zzJliiJ
I
TU d6
dugc:
ta c6 Phrrong trinh dbng diQn:
go, zs+ + j18,981
Lr:j-L i0,463
'l
iLE,Asl l-'lzas,+nit"'] =f
0,156+i0,472)
o
|
so,sei@zz'-zs's'l
o
)l+zyi{377'+r72'8"))
Kdt qu6 nay c6 thd kidm tra bhng c6ch sfi dSng quan hQ gifra v6ctd
khdng gian vi v6cto pha (5.61) vA cdc v6cto pha f",f" trong vi dg 5'1:
f
tl=L,s\f2eis77,|{"]=,,uJ-rn,""l?1'*,t,iit".l=luo'u'],1'lL'":::ll"
Lt;l
-'-'--
Lil-r'vv-v
)
L22,2"irzz'e'
l+z,ui@77t+r72'8)
)
Theo phrrong trinh (5.51), m6men tlQng co tlugc tinh bdi:
74 = ? x 3 x 0, Oa t Im (so,
=3x
3
i.z
B
x
pGuven
0, 0
+t(so,s
[i
srEu
fuej
x +2,
@7
1
7
t -25'5")
v
sin (-25, 5'
KHTEN
47,1n-
-
j
@7 7 t
+17
)
172, 8")) =
DINI ttUdnc
(FIELD-ORIENTED PRINCTPLE) VA GAC Sd
2'8')
6!,2Nm
TUA THEo TRUd
0d slEu KHI€N
Dl
HUdlrc THEo vEcrd rU rnOnc ROTo
qudt. mOt dOng co tliQn trrdng tr,r nhrr mQt ngudn m6men
otEu xutEN vECTo oOna co KHING o6No ao
ddng co duoc ddt ra trong cric hQ truydn d6ng c6 ddc
dung phrronC phdp di6u khidn vi tri truc r6to.
2IT
tinh
dQng cao vd sfi
M6men sinh ra trong d6ng co la kdt qud tuo'g tr{c gitra ddng trong
vd td th6ng sinh ra trong h6 thdng kfch tr] d6ng co. TrI th6ng
phdi duoc girt d mrl'c t6i rru nhim d:im brio sinh ra m6men t6'i da va
gi6m t6i thidu mrlc rlQ bao hba cria mach tu. vd,i tr) thOng c6 giri tri
kh6ng ddi, m6men s6 ti 16 thuAn vdi dbng r1ng.
Di6u khidn dOc l4p tr} th6ng vd ddng rt'ng thuc hi6n d6 ddng ddi vdi
d6ng co m6t chidu kich tr] dQc ldp. 6 day, dbng trong cuon stator xd.c
dinh trl thdng, dbng r6to diug dd di6u khieu m6rnen.
Trrong trt trong dQng co kh6ng d6ng b6, cu6n ti,ng li r6to vi tr]
bh6ng sinh ra bdi ddng trong cu6n stator. Tuy nhi€n, dbng r6to kh6ng
drtoc truc ticp didu khion boi ngud' ugodi ma ld h6 quzi do srj,c di6n
ddng ceim rl'ng sinh ra do kdt quri chuydn ilQng ciia r6to so vd,i tr} tnldng
stator. Do v{y, dbng stator ld ngu6n cria tr} th6ng vd ddng rl,ng.
Trong DCKDB r6to ldng s6c, chl c6 ddng stator drroc di6u khidn
trrrc tidp, do d6 viQc didu khidn m6men t6'i uu kh6 thuc hi6n vi kh6ng
thd bd tri c6 dinh vd mat vdt lf gifra ttr th6ng stator vd r6to duoc vri
phuong trinh m6men ld phi tuydn.
Vi6c didu khidn mdmen 6 trang thdi xdc lQp c6 thd mri rQng cho
qud dQ drroc thrrc hiQn trong cric h6 thdng didu khidn v6cto (DKVT), dua
theo nguy6n lf dinh hrrdng trra trudng (FOp). Nguydn ly ndy xdc dinh
cuQn ritng
didu kiQn dd didu khidn d6c ldp tr] th6ng vdi di6u khidn m6men.
DCKDB theo phuong phrip DKVT m6 ph6'g dQng co DC theo hai
phlrong di6n:
- Tit thdng vd. mdmen c6 thd didu khiein d6c lqp
- cdc di6u ki€n ad ai6u khidn m6men toi uu cho cri hai trang thrii
xdc l{p vd qud d9.
Diiu kiQn
diCu khidn m6men t6'i rru
Didu ki6n dd m6men t6'i rr' dat dtroc khi cuQn ddy mang diQn dat
trong tr} trudng vdi m4t phdng cuOn ddy song song vdi dudng sf'c ciia tr}
trddng. Khi d6, vdctd ddng di6n ciia cuQn day i s6 vu6ng g6c vdi v6cto
tir th6ng 6 tH.s.rr).
6.2.1
CHUdNG 6
Hinh 5.77: Didu kiAn dqt mirnen kh6ng tdi uu (a) ud tdi uu (b)
i
Hlnh 5.72: M6men sinh ra trong dQng co DC
'lhdi qu6t cdp dbng fng cho cuQn rdto th6ng qua cd g6p tlrrgc b6'tri
v6ctd ddng tt"g ,t lu6n vu6ng g6c vdi v6cto tt th6ng 6p, sinh ra
r stator. M6men dQng co tt lQ vdi dbng rrog vd tit thOng kich tic
.
M =Ke*tiu
ri:rg vd tU th6ng kich tr} c6 thd drroc tlidu khidn mQt cdch
q trinh tr6n ttlong duong md hinh b0 bidn tldi tuydn tinh
otEu xutEN
vEcra
co KH)NG o6Nc a0
oor,ta
Hinh 5.73: M6 hinh cila dQng co DC kich
5.2.2 MO
dQ
hinh dQng
crria dQng cd
tt
dQc l6.p
kh6ng d6ng bQ trong hQ trgc tqa
xoay dq
Phrrong trinh m6men trong hQ truc toa dQ xoay (5.91) c6 thd s6p
xdp lai sao cho mdmen ld mQt him phg thuQc dbng stator vd tU thdng
16to.
Th4t v4y, tU phuong trinh (5.88):
(5.e2)
i: =+(*", -L^i:)
Thay (5.92) vdo (5.91):
*
vdi:
=
A+
(5.e3)
(t;,r"o, - i"oto!,)
,, =fr
Dd xdy drrng m6.hinh dQng co vdi c6c thdnh phdn ddng ifi, vir
cria v6cto ddng
ii,
{ ld cdc bidn ngd vdo vd m6men M ld bidn ng6 ta, cdc
thdnh phdn Oi" vA
<D[.
Tir (5.86), do u! = I
s6 drloc bidu di6n thdng qua
ii" vit i"q" .
'
R,ii +(p+"lt"z)oi = o
(5.e4)
Thay (5.92) vdo (5.94):
pe", =
|1"^t:-
(1 +
iost" ) oi ]
(5.e5)
Ph6n tich cilcv6cto thdnh cdc thdnh phdn dq, ta duoc:
.",.i" I
*i, = +(?i"o" - )o"0,*
rr
P[rr
)
(r
.r
(5.96)
Cdc phrrong trinh (5'93), (5.96) vi (5.9?) mO tA md hinh tlQng
dQng co kh6ng tl6ng bQ, tlugc trinh bAy tr6n hinh 5.14 cho thdy
phrlc tqp khi didu khidn DCKDB.
tot:"
h'i't3^
o*o!n
h'3,t3;
1^"
Illnh 5.74: MO hinh d6ng crta DCKDB trong hQ tr4'c tqa dQ xoay
6.2.3 Di6u ki€n di6u khiCn dinh hrrdng theo trddng
(Didu khidn dinh hudng theo udcto til th6ng)
Nguyen lf ttidu khidn ttinh hrrdng tr,ta theo v6cto tu th6ng dqra tr6n
phrrong phdp phAn tdch phi tuydn dugc srl dgng trong tli6u khidn cdc hQ
thdng phi tuydn. BAn chdt cfia phuong phdp ndy lA di6u khidn cdc bidn
dd chgn sao cho chfng luon blng 0. Nhrr vay, mO hinh todn hgc sE trd
n6n don gi6n hon vi c6 thd lo4i b6 mot sd nhdnh trong m6 hinh tdng
qu6t.
Tt
phrrong
trinh
(5.93), ndu:
(5.98)
Qi, =o
thl:
"
vdi:
=#,+api;,=ke;,ii"
L^
k=+b=T
'3 L,
3R, r,
Ndu didu kiQn (5.98) thol
vi:
(5.ee)
(5.100)
r
otEu,xutEt't vEcro oQna ca rcuOuo
fiNa
215
eQ
Kh6o sdt gi6n dd khdi tr6n hinh 5.14 vdi clidu ki6n Qi. = 0 cho ph6p
lrtoc bdt gidn tld (H.5.15). M{t khdc, c6 thd thay cdc hdm chuydn ddi tU
if;" -> Q"a, trong md hinh bdi hdm truydn G(p):
Hdm truydn G(p):
1
L^
P= - trP+l
t" 1+ 1 1
i"d"=L^
G(p\=Q"a,
-'\r 'f
(5.112)
P7,
Kdt qud ta dugc so do' tr€n hinh 5.16. Vi€c didu khidn dQc lap
til th6ng c6 thd dat dugc. Drip rlng m6men khi c6 srr thay tldi
ddng if" ld trl'c thdi, elip rfirg cria tU th6ng Or; khi dbng tA thay ddi c6
qu:in tinh vdi thdi hlng t,.
m6men vA
Hinh
5.75: So d6 khdi crta DCI{DB
khi thdnh phdn
Qi^
=g
Hinh 5.76: So d6 khdi cfia DCKDB dlnh hudng t(a trtrdng
Tr
(5.94):
!
't
216
Ndu (5.98) vd (5.101) thoA, nghia la o;. = 0 vi PQZ, = 0, thi
phdn ij, = 0 vd chl tdn t?i thdnh phdn 6o cfia v6cto ddng r6to: if = j
Ddng thdi, do @i = @X" nhrt dd kh6o sdt 6 tr6n, v6cto dbng r6to vd
th63g r6to vu6ng g6c vdi nhau d moi thdi didm ( ii f @7). D6y chinh
didu kiQn tljdu khidn m6men tdi mr.
Do 6nh hrrdng cfia g6c tao bdi hai v6cto ii vd, @",16n m6men sinh ra
n6n g6c ndy cdn goi ld g6c m6men.
iq
|
|
*on
^9
O
Hinh 5.77: Ctic udcto atAng rato ud. tt th6ng trong dQng co
KDB dlnh hudng tua trudng
5.2.4 C6c so d6 diiu khiin dinh hrrdng trta theo v6ctd tfl th6ng r6to
Hai phrronC ph:ip tidp c4n trong tlidu khidn v6cto trl th6ng thudng
drrgc sfi dung:
- Phrrong phrip tlidu khidn
trqrc ti€-p: sfi dgng cam
bidn dd do tn/. c
tidp tir th6ng dQng co;
- Phrrong ph6p didu khidn gi6n tidp: dua tr6n viQc do vi tri r6to'
1- Di6u hhidn dinh hdtng theo v6ctd til th6ng r6to
So tld kh6'i cria hQ thdng didu khidn v6ctd dQng co kh6ng ddng b0
duoc trinh bdy tran hinh 5.18. H0 thdng tlinh hrrdng trra theo v6ctd tU
th6ng t4o ra c6ct'in hiQu ddng stator tl4t 6 ng6 ta ,;,rb",,;dua tr6n tin
thdng rdto vd m6men tlQng co qi,M-. BO nghich
Itru c6 nhiQm vg cung cdp dbng stator i*,i6r,i"" theo c6c gi6 trf ddng y6u
cdu ,|,1i",1j".
hiQu ddt ng6 vAo
ld
tt
Nhu de trinh bdy tr6n hinh 5.16, trong DCKDB dudc tlidu khidn
tlinh hrrdng theo v6cto til th6ng, cric thAnh phdn dbng stator ifi" vit i"o"
I
orEu xurEN
vEcro
oONa
co xuOxa o6va
2L7
eO
ti6n s6 chuydn tldi tin hiQu <Di vd M" thdnh tin hi€u didu khidn tudng
ttrrs ,2, ve ii" cna v6cto ddng stator trong hQ truc toa dQ dq, vi sau d6
chuydn ddi tin hiQu ndy sang tfn hiQu di6u khidn crlc pha ddng stator
l,o" rl6s rLB .
Ngudn DC
as
o
He thdng
dinh ht/6ng
tua trudng
BO
bs
nghich luu
M
cs
u"
T
Tin hi6u
hdi tiep
Ilinh
I
i".
ltl I
\l
.a-
w
Dong cd
khdi tdng qutlt hQ thdng didu khidn
uicto DCKDB
t;,t;",i; st? dung ph6p bidn ddi
rfr
Dd chuydn tin hiQu ,i]
"e
"attg
cp+obc(xem (5.15)) vd dd chuydn ddi tin hiQu ijl vdifl sans iiviti"*
5.78: So d6
cdn sfi dLrng ph6p chuydn figc dq-+ap(xem phrrong trinh 5.82).Tuy
nhi6n trd ngai d ph6p chuydn tnlc dq + ap ld cilc gi6 tri cria thdnh
phdn rrlt . Vdn dd la hC trgc tga dQ xoay dq drroc dinh nghia quay cing
vQn t6'c g6c vdi c6c dai lugng v6cto cria dQng co nhung chua c6 gi6 thidt
vd sqr ddng bO cfia hQ truc ndy vdi c6c dai lrrong v6cto dA dd c{p. W thd,
mQt dqi htqng u1cto sE duqc chgn ld.m chudn dd dinh ui hQ trqc tqa dQ
xoay dq theo udcto nd,y. Ddy lA brin chdt cira phrrong phdp didu khidn
dinh hrrdng hQ trr;c tqa d0 xoay tqa theo v6cto chudn. TrOn thr.tc td c6
CHUdNG 5
2L8
ph6p tidp c4n kinh didn, v6cto thrrdng dugc chon ldm chudn IA v6cto tU
th6ng r6to iDi vd hQ tn;c tga dQ xoay dq sd drrgc clinh v! theo v6cto ndySo dd didu khidn v6cto trong trudng hop ndy tlugc goi ld so dd dinh
hudng t(a theo utcto ttl th6ng r6to.
Vi tri g6c cria v6cto til thdng rOto Qi trong hQ truc tqa d0 tinh crp
tluoc dinh nghia la O,. Ph6p bidn hinh dq -+ ap cluoc vidt lai ld:
[';:l= fcos(e")
j= lsin(e")
Ld
-sin(e")lf,;:.l
j
cos(o"l iLrfi
(b.r14)
Hai hQ trgc tga d9 da duoc ddng b0 h6a theo v6cto chudn Oi
trinh bdy trdn hinh 5.19.
Pl
\,"
";l----------"--z
/oz^
tlrrgc
d.\
ots'
q
\o)
o?*=0./
Hinh 5.I9: Dinh hudng hQ trryc tqa dQ xoq'y tga
theo vdcto til thing r6to
dQ xoay nhrl vQy hodn toAn th6a mdn
(5.98).
m6
hinh h6a nhrr hinh 5.16. Tt thOng
DOng co s6 drrQc
tlidu kiQn
r6to s6 drrgc didu khidn blng cdch higu chlnh thinh phdn ri" cria v6cto
SU
tlinh hrr6ng cria hQ trgc toa
ddng stator mQt cdch dQc
l{p
so vdi
tliiu khidn
m6men th6ng qua viQc
I
otEu xutEu
vEcro
DQNG
ca
2L9
KH1NG odt'ta aO
mot
Y6u cdu duy nhdt ddi vdi so dd di6u khidn ndy ld viec x:ic dinh
(Di.
niy
Didu
v6cto
cfia
c6ch chinh x6c gi6 tri g6c 0, , c6 nghia ld vi tri
c6 thd duoc thrrc hiQn mQt c6ch trqrc tidp ho4c gi:in tidp'
dinh ht(mg theo v^eto tit th6ng r6to tr{c ti6p
(pha)
Trong so dd di6u khidn v6cto trgc tidp, bi6n d0 va vi tri g6c
gi6 t4 tliQn 6p vd
cria v6cto til th6ng chudn Cltrgc do ho{c rrdc tinh ttt c6c
rlng Hall
ddng stator th6ng qua cdc bQ quan s6t tir th6ng. cam bidn hiQu
bidn ndy
c6 thd drroc srl dung tld do tt trrrdng. Bhng c:ich d{t cfic cfum
p, c6 thd x6c dinh
vdo trong khe hE kh6ng khi c(ra dQng co 6 truc cr vir trgc
kh6ng khi o;.
c6c thdnh phdn tucrng rrog cfra v6cto ttt thdng khe hd
2- So
Tt
d6
ai6u hhidn
thong khe hd kh6ng khi do duoc tr6n sd dd dgng cria DCKDB
dang T (H.5.20):
A"^ = L^i"^ =
Suy ra:
i;
Z- (;; +;;
(5.115)
)
(5.116)
=|o;_;;
Do v6cto @i kh:ic vdi v6cto
O;
bdi tU thdng tAn trong r6to' vQy:
oi = oi" + L6ii= ol + a,
=['.*)"
-Lt,ii
[*.;
\"-
-t:
I)
(5.117)
=*rr-h,ii
l'*
L,
Hinh 5.20: So dd dQng tuong duong crta DCKDB
Ph6ptinhtUth6ngrOtotr€ncos6vixfrlfdrroctrinhbdytr6nhinh
5.21 gdm c6c Ph6P todn tl4i sd:
hi€u i,-.vitii.tludc tinh til dbng stator thu.c i^,j6,,1",
s&
2- Srl dung phrrcrng
fiinh
(b.112) tfn hiQu
O| vn <Dfi, drroc xric rtinh ffii;
*,
=*r"o^-Lt,r&,
(5.1
,A,
=*rfi^-h,g"
(5.119)
3- Bi6n dQ vd g6c pha
dinh blng ph6p chuydn
<D"
vh 0"
cria v6cto trl th6ng r6to duoc xdo
trgc:
,
O| +7Ofi" + Q,20.
(5.120)
KhAu tinh to6n tU thOng r6to
Hinh E.2t: &ic dinh
ut;;;;;-; ,l ,,t ri"rr;;;;r;;;;i"-"i-i**,
bidn Hall ud hhdu tf.nh todn til th6ng
Tr6n thrr.c td,
ti
sd
?
"m "uL;.
"u^
kh6ng bi 6nh hrrdng b6i srr thay ddi
cdc didu kiQn vQn hdnh cria dQng co nhu
nhiet d6 cuQn d6y hodc su b6o
hda mach tt. Do d6, ky thuQt didu khidn dinh hrrdng tua theo v6cto tir
th6ng r6to dtroc xem nhu mQt trong cdc kj thuQt dn dinh vd chinh xdc
nhdt. Tuy nhi6n, y6u cdu ddt c6m bi6h Hall vdo trong khe hd kh6ng khi
ldm tdng gid thdnh vA giAm dQ tin c6y cia h€ truydn dQng.
Trong dQng co c6 sd' d6i crr. c p = 1, ngtrdi ta ddt c6m bidn Hall 6
r".u.rl). Do @2, =e,
T9"
zp
(H.b.19) n6n bidn ng6
ra
<D, cria
khau tinh
to6n tr] th6ng r6to c6 thd sfi dung lim tfn hiQu hdi tidp trong mach vdng
di6u khidn tt thong. Bidn @. cring drroc srl dung dd tfnh todn m6men
nhlm dat
drroc
tfn hiQu hdi tidp m6men cho mach vdng didu khidn
I
ca xuOuc odvo
otEu xutEN vEcro oOxa
eO
KhAu tinh todn mOmen duoc trinh bdy tr6n hinh 5.22 gdm cdc brrdc
nhu sau:
1- Ph6p bidn
hinh
abc
+ op
drroc
sfi dung cld chuydn ddng stator
i*,i6, ,i"" -+ e ,d"
2- G6c Q, ldy tr} ng6 ra kh6u tinh to:in tr} th6ng r6to drroc thay vio
c6ng thrlc (5.81) cho ot nhlm chuydn t,d" - fi c0a v6cto ddng stator
trong hQ truc toa d0 xoay dq.
3- Bi6n dQ @" cria tt th6ng r0to,
th6ng rdto, drtgc giA srl
m6men fr (5.100) ad
til
ng6 ra cria khdu tinh to6n tr]
blng @i,, nhdn vdi thdnh phdn ii" vd hXng sd
tinh m6men (5.99).
os
cs
<D,
=O 3,
i::
i;;
Nghich lrtu
Hinh 5.23: HQ thdng didu khidn dlnh hudng t(a
tt
th6ng r6to co bd.n
224
,"r;=+:r;
Tin hiQu ifs
trJonS rlng
.o*
(5.1
vdi m6men att
ttf
drroc xdc
M*
'is=d
dinh
tt
(b.99):
(5.129)
H9 thdng didu khidn v6cto rlQng co kh6ng ddng b6 theo phrrongl
phdp dinh hrrdng trra trr th6ng r6to gidn tidp tlrroc trinh bdy tr6n hinh
5.25. Trong so dd ndy, tt th6ng vd m6men dQng co drroc didu khidn kidu'
vbng hd vd kh6ng c6 cac mach vbng hdi tidp ttd hiQu chinh c6c gi6 tti
niy. vi thd, ddc tinh cfia hQ tho'ng phu thuQc rdt nhidu vdo viQc x6c rlinh
chinh xdc c6.c thong sd cria rlQng co. Y6u cdu ndy thddng kh6 tho6 m6n
trong cdc (tng dung thrr. c td Tuy nhi6n tru tlidm ldn cfia hQ tho'ng didu
khidn girin tidp ndy ld c6 thd s& dung cho cdc loai dQng cd thudng gep
(standart) vdi vi tri roto c6 thd d6 dang do duoc bxng mQt cdm bidn gdn
ngodi.
or
MNghich luu
+0
Hinh 5.25: HQ thdng didu hhidn u6cto DCKDB u6i phuong phdp dinh
hudng t(a td th6ng r6to gidn tidp
ViQc xdc dinh vfn tdc tnrot theo c6ng ttritc (8.L27) cho thdy s{ phu
thuQc rdt ldn vdo thdi hlng r6to t,. Rdt ti6c, gi6 tri r, bidn thi6n ddng
kd trong qud trinh vQn hdnh cfia DCKDB, do s{ thay tldi di6n tr6 r6to
theo nhi6t dQ, do hiQu rlng bd mdt tron day ddn r6to, phu thu6c tdn sd
vd mrlc b6o hba tir cria tliQn khring r6to.
Nhin chung, so d6 didu khidn dinh hrrdng trra theo trudng gi6n tidp
don giin hon so vdi so dd trrrc tidp, tuy nhi€n do nhitng nhuoc didm kd
tr6n, d{c tinh cfia so dd gi6n tidp s6 k6m hon ndu kh6ng 6p dung cdc
gi6i phdp d{c biQt khdc.
btEu xutEtt vECTo oONa
co
xuOr,ta o6Na ao
225
phrip di6u khidn khric nhau, d5. drtoc tidn hdnh trong nhrirng thQp ni6n
gdn ddy, t{p trung vdo ba vdn dd chinh:
l-
Cdc khd ndng dinh vi hQ truc toa dQ xoay. Dt phuong phrip
truydn thdng dinh hrrdng theo v6cto tt th6ng rdto cho kdt quri tO't vii vigc
phrin trich mQt cdch tr.r clQng di6u khidn mdmen vi til thdng, cdc v6cto tr]
th6ng khdc nhrr tU thdng stator vd til thdng khe hd kh6ng khf cfrng c6
thd drroc stl dung vdi cdc tnr didm ri6ng so vdi so dd truydn th6'ng. Didu
tl6 d6n tl6h viQc ra ddi cria cdc hQ truydn tl6ng didu khidn DCKDB dinh
hud^ng tua theo v6cto tr] thdng stator ho{c v6cto til thdng khe h& kh6ng khi.
2- ViQc khfi b6 cdc c6m bidn tlo trrrc tidp vh thay chring blng cric hQ
quan sd.t, nhQn dang gidn tidp, d{c biQt le ddi vdi tir th6ng vd vQn tdc.
3-
C6,c
sd dd didu khidn thich nghi, gdm x:ic dinh trong ddng
(on-Iine) cric th6ng sd tlQng co vd hiQu chinh hQ thdng didu khidn.
Vi dg 5.3. Cho dQng co c6 tham sd nhrr vi du 5.1 v4n hdnh 6 trang thrii
xric l{p trong cdc tli6u kiQn dinh mrl'c.
a) Sfi dung kdt qui cria vi du 5.2 dd tinh torin v6cto til th6ng khe hd
khdng khi vd v6cto tr] th6ng r6to tir sd tld alQng tudhg drrong cria dQng co
(H.5.20).
b) X6c dinh cdc thdnh phAn crp cria v6cto tr} th6ng r6to bhng cdch st
dung kh6u tinh torin tr) th6ng r6to tr6n hinh 5.21 vdi cric th6ng sd do
tlrroc Id ddng stator vd tU th6ng khe hd kh6ng khi. So sdnh kdt qud dat
duoc vdi cAu a.
Giai
a) Tr]
vi du 5.2 ta
c6:
.la
l,;l = [
L;:
I
50,5ei?77t-2u'u")
147 ,1"i(azt'*r72'8")
)
vi thd:
t
=
ij +ii
=15,g"1(377t-e4'2"),A
vd
At^ =
L^i"*
= 0,6511e/(377t-94'2) ,Wb
V6cto tr} th6ng roto c6 thd xric dinh nhtr sau:
oi = oi, + L1,il = 0,6496ej(377t-s7'2")
C6 thd
tinh
duoc 96; gif,a v6cto
tt
th6ng
vi
,wb
dbng r6to ttd xdc dinh
CHUdNG 5
b) ThAnh phdn cp cfia v6cto dbng stator vh v6cto tir th6ig khe hd
khdng khi ld:
ii, = 50,5 cos(377 t - 2s,5'), A
{"
= 5o,5sin
(377t-25,5o),A
oL = 0,6511 cos (377 t - 94,2"),wb
oi- = 0, 6511sin (377 t - 94,2"),Wb
Theo (5.118) vn (5.119)
oL
0i
=
14,T,.
0.041
0, ob
= 0,6496cos
00=a,T
ofi"
vd P'=
=
0,041
0,
1
I cos ( gzz t
-
g4,2') -
o,
00074 x 50,
s cos
(azz j
-
25, 5")
(ZZlt -SZ,Z'),Wb
t o, 65 1 1 sin (37 7 t -
g4,2") -0, 00074 x 50, Ssin (377t
- 25, 5')
6496sin (37 7 t - 97,2),Wb
2"),Wb
ra: Oi = OL +ioi" = 0,6496er(377t-s7
Kdt qud phil hop vdi cdu a chrfng minh tinh thing ddn cfia phrrong
phdp x6c dinh bian tlQ vd pha cria v6ctd trl thong rdto tir edc 976 tri tlo
d4c ddng stator vd c6c thinh phdn kh6ng gian cfia v6cto tir th6ng khe
suy
hd kh6ng khi.
Vt dB 5.4. Cho dQng co c6 tham sd nhrr vi dg 5.1 vd'i hQ thdng di6u khidn
dlnh hrrdng trr. a tnrdng tr{c tidp vdi c6c didu kiQn v{n hinh htdng tU vi
dq 5.3. Tinh to6n c6c tl4i lrrgng ng6 ra cfia khdu tinh todn til thOng vA
m0men v6i c6c gid tri ldy m6u cfia til th0ng khe hd khOng khi vA ddng
statordt=5ms.
Giti. C6c Crd tri dbng stator I thdi clidm ldy m6u duoc x6c dlnh tU vi dg 5.1:
i" =23,82-25,5"A
vdi t = 0,005s + o"t = 377x0,005 = 1,885 rad = 108o- Suy ra:
i*
=,12x23,8cos(108'- 25,5)= 4,4A
i6" = ,,1i, x23, 8 cos (108" - 25,5 - !2Oo) = 26,7 A
iu =.,!ix23,8cos(108"- 25,5 -24o)= -31,14
Cdc thdnh phdn ap cria v6cto
tlinh tilvi dg 5'3:
oL
tt
thOng khe hd kh0ng khi drro;c x6c
=0,6b11cos(1 o"-94,2)=o,6828 wb
torEu xutEu
vEcro oQxe ca xuOno
fixa
aq
p
drroc tinh todn
Sfi dgng
thdnh phdn cp ddng stator
sau:
I
o,ol ,
l-f
-
|
I
sfi dung
"*':l :'#,T];:i
ai-
=
ffix0,15b3-
fso,r.J'^
::1,0, n,u,u
=
0,6382 wb
0,o00z4xb0,t = o,t2og Wb
Bi6n d0 vd pha cria v6cto tu th6ng r6to duoc tinh to6n nhu sau:
l6
o. =,/o;'+ofl.'
/_. \
0, = tan-l
=JW
l#j.[.s"(o;)-r]xoo"
=0,6496 wb
=
tan-r
(ffi).
(1-l)xe0'
= 1o8o
Khdu tinh todn m6men ddu ti6n ciing thrrc hiQn ph6p chuydn truc
abc -> crp cho dbng stator nhrr kh6u tfnh todn'tt th6ng (tuy tr6n thrlc td,
ph6p chuydn truc ndy chi thrr. c hiQn m6t ldn cho hai kh6u tinh to6n). srl
dung (s.gg) dd tfnh todn m6men dQng cd, trong cl6 thdnh phdn dbng
diQn iis duoc xdc dinh til (5.114):
{s = -6,6sin(t0,8')+
vd do
h
M
n6n:
vi
=lx_j!-=
3 0.44fi
50,1cos(10,8") = 4g,0A
1,966 NmtWbt A
= 1,966x0,6496x 48,0 = 67,2Nm
du 5.5. cho dQng.co c6 tham sd nhtr vi du 5.1 vdi he thdng rri6u khidn
tlinh hrrdng trra trudng truc ti6p. chfrng minh tinh bdn vfrng d6'i vdi srr
thay ddi thdng sd dQng co bXng cdch gid thi61 cdc khriu tfnh torin td
th6ng vd. m6men s& dung cdc gi6 tri diQn cam kh6ng chinh xdc. vi dg
giri tri diQn c4m h6 trrong L^ l6n }non 2ovo gi6 tri thrrc vd rliQn cdm t6n
L6l6n hon 40% gid tri thrrc cria chring. Tfnh to:in cric tin hiou hdi tidp try
th6ng vi rn6men tudng trr nhu vi du 5.4 vd so sdnh k6t qu6 dat drroc.
Giai
c)
CHUONG 5
228
.t = H#x0,6323
- 0,00104x6,6
= 0,6388 Wb
0'05024x0,1553-0,00104x50,1= 0,1065 Wb
oiP'.=
0.0492
Q, =0,6476Wb
0' = 9,5o
suy ra:
So s6nh vdi kdt qua tinh todn 6 vi dr,r 5.4 la 0,6496Wb vd 10,8o, c6
thd thdy sai sd cria bi€n do tu th6ng tinh torln chi khoang o,Tvo vd, sai sd
g6c pha
Id
l2Vo.
tinh to6n mdmen:
lfs = -6,6sin(s,s')+ 50,1cos(9,5")= 48,3A
Ttrong tU, cho khdu
n
M
9'9!!?, =r,eseNmtwbt
3" 0.05024
=9
= 1,959 x0,647
A
6x 48,3 = 6l,3Nm
sai sd g6c pha cria khAu tinh todn tr] th6ng kh6 cao, sai s6'ctia
khAu tinh todn momen cfrng chi khodng O,2Vovit tren thuc tdsai sdndy
Di
drtoc coi lA
lf
trrdng
Vi dq 8.6. Cho tlQng co c6 tham sd nhrr vi du 5.1 van hdnh vdi hQ thdng
tli6u khidn dinh hrrdng trta v6cto til th6ng roto girin tidp (H.5.25). Cdc tin
hiou y6u cdu di6u khidn tr] th6ng r6to vd m6men dQng co c6 gi6 tri
ol = 0,6496 Wb vd trf - a\2 Nm. d thdi ttidm r = 0,5s kd tt] khi dQng
cd khdi tlQng, gii thidt r6to dd xoay 10 rad, h6y tinh:
a) Cdc thinh phdn ddng stator d{t trong hQ truc toa dQ xoay
6 va ris
b) cric thdnh phdn dbng stator ddt trong hQ truc toa
;$ va a,i"
c) Cric thdnh phdn ddng stator
d4t
dQ tinh
i|,i;, "e ,;.
Giai
a)
C6c
tin hieu
ij! va ;[, drlqc tinh tir c6ng thrl'c (5.128) vd (5.129):
.o* 0,6496 ro,o4A vdi p = 0 d xdc I4p
tr)c
=---:--:-- =
0.041
6L,2
oEu rcnEN vECTo olna cd rcuOxo o6Na ao
b) V4n tdc trrrot
rr:sl. drrgc
'l'
G6c
0i,
G6c
0
drroc
229
tinh theo (5.725):
=#
"m,=rr'33rad'ts
tinh d thdi didm t = 0,5s nhrr sau:
0"1 = <orl .f = 11,33x 0,5 =5,661rad
cria rdto d6ng co ndu
tfnh
cldn s6'd6i crrc khric 1 lh:
t =3"L0 =BOrqd,
Do d6 g6c 0, cho bidn ddi truc dq -+
cxp
Id:
0" = 0lr +0=35,665rod
tudng duong 243,5o.
Tr) c6ng thrl'c (5.114):
'l
f,;: I _ fcos(zae,s') -sin (24s,5')lf rs,aa1 _ | as,az o
L*l- lsin(2a3,5') cos (243, 5") lL47 ,e2 ) l-as, so.l '''
c)
Tt
cdng thrl'c (5.16):
2
lo,
Lb" =
1""
5o
11
:
3Ja
_1
o
k)
1
./g
Cdc ph6p todn trlong t{ (mgc a + c) s6 drroc thuc hiQn cho m6i chu
ldy mAu cfia hQ thdng didu khidn sd dQng co.
Vi du 5.7. M6 ph6ng s6'didu khidn tdc dO ilQng co theo phuong phdp dinh
hrrdng trra trrrdng gi6n ti€p cfia hQ truydn ddng il6ng co kh6ng d6ng b6 b0 bidn tdn r{p didu khidn theo dbng di6n.
Khdi dQng Matlab 6 vdo DemolBlocksets chgn Power System.
chon frle AQ Motor Drive - v6cto control vd Run AC Motor Drive.
MO hi m4ch: DCKDB Cluoc cdp ngudn tir mgt b9 nghich lru 6p didu
khidn theo ddng tliQn. DQng co k6o trii co ddc tnrng bdi m6men qu6n
tinh J, h6 sd ma sdt B, vA m6men #i TL.
Mach vdng didu khidn t6'c d0 srl dung khAu hi6u chinh p/ ild hinh
CHUANG 5
KhdiDQ-ABCtlrrocsrldgngddchuydnttditinhiQujd*vddq*thdnh
tin hiQu dbng tl{t ia*, ib*, vi ic* cho khdu hiQu chinh tlbng'
DiQn 6p vi dbng tlrroc hidn thi qua cdc khdi tlo'
Dbng, tdc dQ vi m6men c6 thd quan sdt d ng6 ra cria khdi
'Asynchronous Machine'.
R" = 0'087C1'
DQng co c6 thOng sd nhu sau: 50 HP, 460V, 4 cpe' 60Hz'
Lr = 0,8mH, L* = 34,'lmE, R, = 0,228d2, Lh = 0'8mH'
tr
More inlo
M6 ph6ng
.1- Chay mO ph6ng' Quan s6t ddng dQng co' diQn 6p' t6c tlQ vd
m0men hic khdi dQng tr6n khdi Scope'
th6i x6c
2- I<Iikdt thric thdi sian m0 ph6ng (1,5s), hQ thdng d4t tr4ng
xdc lfp c6 thd ghi nh6n blng c6ch chgn trddc d6:"
workspace I/O/Save to workspace/Final state" trong simulation/Parameters'
lflp. Cdc gi6
tri 6
3-Thaythdgidtrikh6ngtlditoc.lod4twrefvimOmenteiTLbdi
ddi til 120
hai hdm ndc vdi thdi gian bdt ddu khdc nhau. Tdc tlo d{t thay
6 t = 1'4s'
ttdn 160 rad./s 0 t = 0,2s vd m6men thay ddi tir 0 ddn 200 Nm
chgn "workspace I/O/Load from workspace/Initial state" trong
ring cria
simulationlParameters. chay m6 ph6ng lai vd quan sdt ddp
truydn dQ,ng.
hQ
r
otEu xudr,t vEcro o2va co xuONa odxo a6
0
-500
t000
I
aOO
n, ttrt-l
300
200
100
0
-100
-200
Tdc dO,
150
[radd/s]
i
50
0
0,5
1,5
1
Kh&i dQng dQng co kh6ng ddng
bQ
CHUONG 5
232
Vab (V)
is_abc (A)
T6c d0 (rad/s)
Ddt tinh dQng cila hp thdng truydn d6ng
r
otEu
xuEx vECTo oONo ca xuONa ooNc
s.3
NGUyEN
lf
olEu xHldu TRUc
233
eQ
rlfp
tvtOmrru
(DtRECT T)RQUE C]NTRjL)
Gidi thiQu
M6t ki thuat rlidu khien mornen DCI(DB v6'i ugudD nu6i Id b6
nghich lrru rip PWM khric v5'i Dguy6D ly dinh hrr6'ng trla trudng c[ng
dUoc chri trong nghi61 crlu phrit tri61 nalh hi6n nay li lguyen ly di6u
khidu tnrc tidp m6men (DTC - Direct Tolque Control) hodc cdu c6 t€u
goi kh6c ld trr tli6u khid[ tnrc tidp (DSC - Direct Self control).
Ky thuat mdi ndy dlc trung bd'i tinh don gidD, ddc tiDh di6u khi6n
hiQu quri cao vd tinh dn dinh nQi. Vi6c srr dung so d6 DTC hoic DSC cho
ph6p didu khidn m6men v6'i dac tinh do[g cao (vAi rns) mA kh6ng cdn
cdm bien cd gin vdo truc d6ug co. Vl va."-' DTC va DSC thu6c hS ky
thuat di6u khidn kh6ng d.i-rug criur. bi6n (seusorless type) vdi uu di6'rn vd
gi6 thduh vd ilQ tin cqY.
Czic so dd DSC thrrdug f'ng dung dieu khiel d6'g co c6ug sudt ldn,
cb1 sd dO DTC thuolg duo-c ding cho day dorrg co cong sudt nho vA
1-
trung biuh.
2-
Nguy|n ly d.i6u lzhidn tr(c tidp tnimen (DTC)
BAnq
tham chi6u V,,
D6 cd KDB
Hinh
5.26: So d6 hA thdng diau. hhi.dn tr4tc ilA'p ntdnten
Thuat ngrt ,,didu khi6'D truc tidp m6men" xudt ph:it
(H.5.26). DUa trel
ti
nguyen lli
sai sd girla cdc gili
CHUdNO
234
'
ve til th6ng, c6 thd di6u khidn trqrc tidp trang th6i crfra bQ nghlch ILU
PWM thdng qua tin hiQu didu khidn d6ng cdt kh6a c6ng sudt nhlm mqo
tlich gi6m sai sd m6men vd til th6ng trong phAm vi cho ph6p drroc x6o
dinh trrrdc.
Sai sd gifra m6men rJdc tfqh M vd mOmen d{t M* duoc drra vdo khtu
so sdnh tr6 ba b6;c (H.5.27a), trong khi sai sd giila bi6n d0 trl thdng
stator rJdc tinh @" vi bi6n d0 trl th6ng stator det O"' tlrrgc drra vio khAu
so sdnh tr6 hai bQc (H.5.27b).
trl thong stator ssn (A0),
Dsa tron gi6 tri ddu sai
"::::'t;v6cto
m6men sgn (AM), giri tri tUdng ddi vd vi tri cria cfia v6cto tit thong stator
6i trong mQt trong c6c g6c mQt phdn s6u cria mQt chu k), mQt v6cto
khdng gian diQn dp cfia b0 nghich l.n 4 (ho4c td hop v6cto kh6ng gian
diQn rlp) thich hop s6 duqc srl dgng trong mQt khoing thdi gian trung
binh ndo
d6.
v3
AM>O
%
AM>0
ao < -ho
ao>ho
AM<0
%
Hinh 5.28
AM<0
%
235
oAu xnEu vECTa oQNo ca xuOtua o6r,tc e0
Gia thidt v6cto tt thong stator d vi tri trong g6c phdn 6 thrl nhdt
(sector 1) trong mdt ph&ng cp. C:ic v6ctd aliCn dp drroc sfi dgng theo k!
thuat DTC tiy theo kdt qud ng6 ra cfia hai khdu so sdnh tr6 duoc trinh
bay tr6n hinh 5.28b vd cot 01 cria b6ng tham chidu v6cto kh6ng gian
diQn :ip (cdn goi Id bAng tl6ng cdt) (xem b6ng 5.1).
Trrong tu nhu v4y cho cdc g6c phAn 6 (0i) khdc (xem blng 5'1)
Bing 5.1: Bd,ng tham chidu uicto hh6ng gian dipn dp
G6c phdn 6 (sector)
AM= +1
AM= -'l
AQ= +1
AM= 0
AQ= -l
AM= +1
AM= -1
0.
0e
Ve
Vt
Vs
Vr
Vs
Vo
Vz
Vo
Vs
Vr
V
Vr
Vg
Va
Vz
Vo
0r
Oz
0g
Yz
Vr
Va
Vr
Vr
Vo
Vz
Vs
AM= 0
0a
Vo
Vo
ViQc chon v6ctd dien dp thich hop trong bQ nghlch funr v"(i) drra tren
phrrong trinh stator trong hQ tnrc toa dQ tinh stator (phrrong trinh 5.17)
do:
(5.130)
=u: -E"t;
dt
Ldy tich phAn hai vd:
Ao:
=
oi -oio = J(r: -&,;)dr
=
u,(i)-4
(5.131)
0
thd khfi duoc bXng c6ch gia tdc
gi6m
sai sd tU th6ng A(D, quf d4o tt
Dd
ho4c giAm tdc tt th6ng stator.
th6ng phai drroc tti6u khidn theo cdc v6cto kh6ng gian diQn dp thich hgp
(5.131) dd tang ho4c gi6m bi6n d0 til thdng ndv (H.5.28)'
Khi y6u cdu ting bi6n d0 trl th6ng, v6cto dien dp cdn drtgc chgn sao
dich pha girla n6 vdi v6cto tr} th6ng hiQn c6 (tai thdi didm clang
cho g6c
-@"0"
phai ldn hon 90o (xem hinh 5.2Sb). Ngrrgc l4i, ndu yeu cdu giAm
x6t)
bi6n dO ti th6ng, g6c dfch pha niy ph6i nh6 hon 90o'
Tdng hgp cdc didu kiQn vd khfi sai sd m6men vd trl th6ng kd tr6n vd
x6t cho tdt ca cdc trudng hop dinh vi cria v6cto tu th6ng stator trong
m{t phEng ap, ngudi ta dii tdng hop drrgc b6ng tham chidu quy lu$t chon
v6cto khong gian dien dp cria bQ nghich lrru (bAng 5.1) vA tU d6 suy ra
quy lu{t tlidu khidn d6ng c{t cdc kh6a c6ng sudt cria b0 nghich lrru.
Ho4c dQ nh4y cfia kh6u so sdnh tr6 (hysteresis band) sc quyct tllnh
thdi gian duy tri m6i.v6cto diQn dp, ho{c ndu thdi gian duy tri v6cto
di€n 6p Ii kh6ng ddi thi tdn sd tl6ng cdt kh6a s6 khong ddi.
Vd thrJc chdt, sai sd m6men AM c6
CHUANG 5,
giri
tri
:ip vd ddng stator do drloc:
6l =1(,:
p'
-4r:)
(b.1s2)
vdi: p - torin tfi Laplace.
Cbn mdmen drrgc rrdc tinh mQt crich don gi6n nhu sau:
M
.C
=;.p
/ ^s-\
Reol["ro"ti
J
Ngodi nhtrng rru didm kd tr6n, hQ thdng didu khidn trrrc tidp m6men
cd bAn c6 mQt sd m4t han ch6'nhu sau:
1- Kh6 tli6u khidn mdmen vd til thdng d vQn tdc rdt thdp;
2- DQ nhdp nh6 dbng vd mdmen kh:i ldn;
3- Tdn sd tl6ng cdt kh6a thrrdng bidn thi6n;
4- D0 dn cd cao d v{n tdc thdp;
5- Kh6ng c6 khd ndng didu khidn ddng tru. c tidp.
Nhfrng nim gdn ddy, cric gi6i phrip duoc dd nghi cho c:ic hQ tMng
di6u khidn trrrc tidp m6men duoc cdi tidn nhrt sau:
1- Sfi dung c6c bdng tl6ng cft cdi tidn;
2- Sfi dung crlc b0 so s6nh c6 hodc khdng c6 tr6, hai hodc ba b4c;
i
3- Ilng dung cric sd tld DTC vdi tdn sd d6ng c{t kh6ng ddi v4n
hdnh, vdi k! thuQt PWM ho4c didu chd v6cto kh6ng gian;
4- lJng dgng k! thu{t tlidu khidn md ho{c m+ng no ron md;
5- Sfi dung c6c bQ rrdc tinh tr}.thOng phrl'c tap dd c6i tidn cl{c tinh 6
vQn tdc thdp.
Vi d+ 5.8. MO ph6ng sd tlidu khidn t6'c d0 dQng co theo phrrong phrip clidu
khidn trrrc tidp m6men cria hQ truydn dQng clQng cd kh6ng ddng bQ - bQ
bidn tAn dp. DCKDB ldng s6c c6 th6ng sd nhu sau: 7,5kW, bdn cuc, R" =
L,177t2, L" = 0,119H, L^ = 0,113H, R, = 1,382C), L, = 0,118H,
J = O,O0L26kgm2.
M6 ph6ng
TrI th6ng dat c6 giri trf <D * = 1,05 Wb.
M6men d4t M* thay ddi nhu sau:
M*=50Nm 0sctS0,2s
M*=10Nm 0,2s<t<0,4s
M*=-50Nm 0,4s<t<0,6s
M*=10Nm 0,6sct<ls
otEu xutEN
vEcro o1va co xuOrto odNc a0
1,4
I
I
-r
1,2
I
FE
z
1.0
a-
-r
-t-
-T-
0,8
-t-
,5
E
o.o
_t_
F
o,o
_i_
I
-t
-tI
-i-
-'i--|--
-tI
I
_t_
-l- I
I
o,2
I
-t-
-t
i_I -l- I
-, 'o
a)
-;
I
I
i--i
tl
ll
ll
I _ _r_ _ J--L
tl
tl
J--L
-l--Lll
_t_ _
I
- -r- - I - -T
f
f
E 08
c
€
!
- tll _ _r_ _ J--L
I
-t I
T
10
-o
I
I
;
1,2 - -r- - f - -r- -
-t- -
I
-t-
1,4
tl
I - -r- - 1--T
tl
-T--T- t--l
I
I
-T-
237
F
o2
0,1 0,20,30,4 0,50,60,70,80,9
Thdi gian,
(s)
1
-0
0,50,60,70,80'9
r-\
P) 0,10,20,30,4
Thdi gian' (s)
1
Hinh 5.29
o) Til th6ng
dfut;
b) Td th6ng stator dQng co udc ttnh duqc
XY plot
iq
1,0
0,5
0
-0,5
-1,0
-1,5
-1,5
-1,0
-0,5
0
1
0,5
1,5
Xaxits
Hinh 5.30: Quj dqo td th.6ng stq.tor
80
60
7E
zi40
-t'zo
(!
5o
a).
;':-
-t-
I
-tI
i
I
I
I
-l-
t-t-
-40
l-
-t)u
t-
-
_t_ -.1 _ _ r _ _r_ _
tl
I
-t-
6-20
-80
80
tl
_t_
I
I
-t-
tl
--!--Ltl
ll
Eoo
I
I
=d40
o
-tI
ot 20
c
-t-
I
-20
€
-+o
E
-60
I
-80
Thdi gian (s)
I
ll
__
hbi-rl
-
r-'.[- 1- -
r+
tl
t- - -ltl
ll
tl
--i--|| t--i€o
c
ll
tl
-t--f--r-I
tl
- - !ll - -L tl
--i--F-ttl
ll
- - r _ -e - -t-
O 0,1 0,20,30,4 0,5 0,60,70'80'9
_ _r_ _
rll
1
b)
tl
-J--l-tl
tl
- l- - + - tl
ll
- a_ - T - tl
0 0,1
,L - -t-
ll
'rtl - -r-
L-t
tl
0,2 0,3 0,4 0,5 0,6 0,7 0,8
Thdi gian (s)
0,9
1
c*ong6
A.A\4.
a\^?af
DIEU KHIEN TOG DO DONG CO DONG BO
6.1 M0 ninn c0n oonc cd ooNc s0
L
GiAi thiQu od d.Qng co DB
DQng co ddns b0 (DB) thudng dugc cdp ngudn ba pha xoay chi6u cho
stator vd r6to c6 dang kich tt mQt chidu hodc kich tit nam chAm vinh
ctlu. Cdc pha dbng stator t4o ra luc td dQng quay vdi v6n tdc diQn ol
(\ =2nfr
(6.1)
Ngugc lai, lrtc tir dQng cria r6to drlng y6n so vdi r6to.
(tlien) cria r6to ld
O, =0h =2nnP
Vfn t6c g6c
(6.2)
nhlm d4t drroc hai gi6n tl6 Igc tt tlQng drlreg y6n so vdi nhau. Cdn bidt
rlng chl trong trrrdng hop ndy mdi sdn sinh m6men trung binh khdc
kh6ng cho mQt vdng quay.
MQt cdch gi6i thich khdc ld m6men trung binh kh6c kh6ng duoc s6n
sinh khi ndng lrrong trl trong mdy diQn W", thay ddi theo vi tri r6to.
' =(ae, -) ,
7a,
I
d9-,
=',
,L=" dt p
(6.3)
tri hinh hgc cria r6to.
\n vay, cdc dang r6to kh6ng c6 cuQn kich tir - r6to tr} trd
vdi: 0, - lA g6c vi
(reluctance) c0ng c6 thd tlrrgc srl dr,rng. Trong mgi trudng hop, sd c{p cqrc
cfia stator vd rdto nhrl nhau.
DQng co d6ng b0 kich trl nam chAm vinh cfiu (PM-SM) hodc dQng co
tldng b0 tt trd (RSM) thudng tltrgc srl dung cho cdc dQng co cdng sudt
239
otEu xnEx rdc oQ o2xa co odua eQ
trung binh vd cao (hAng trdm kW, MW ddn hAng trdm MW).
Cdc d4ng r6to cfia dQng co DB thrrdng g{p (H.6.1 - H.6.3):
- Tich
cqrc:
. Kich til nam chdm vlnh crhr
. CuQn kich til
- Ths dQng:
. TrI trd bidn thi6n
Ngodi ra r6to dQng co cbn tlrrgc ph6n loai theo c{c ldi hodc cgc dn.
CuOn klch
lil
2P
Hinh 6.7: DQng co d6ng
a) R6to kich
til;
bQ
=6
r6to cuc l6i
b) R6to nam'cha'm uinh crtu
lo
Nam chAm
vTnh
cfiu
KhoAng kh6ng
phi tr} tlnh
-sar
CuQn
kich tU
a)
Vat liCu
2p=2
Htnh
6.2: DQng co ddng bQ
a) ROto kich
ttX;
rdto cqc dn
b) ROto nam chdm uinh
ctu
CHUONG 6
240
Thanh chSn
i trl thOng
BQ phan gi0 c{c
(kh6ng tU tinh)
Ldp cdch diQn
Nam ch6m
M4ng phi ttl tinh
a)
)
2p=4
Hinh
zP=t
6.3: DQng co d6ng b6
a)
R6to udi
r6to til tr&
barrier chd'n td th6ng nhi6u l6p
b) R6to phA'n IdP theo trqtc
Dotdcd0criadQngcoDBli6nquanch{tch6vditdnsdngudncdp
ph6i sfi dqng bidn
cho stator nQn tld tlidu khidn tdc d0 cfia dQng cd DB
tdn.
tlq
IJu didm ciua c6c hQ truydn dong tlong cd DB lh hiQu sudt, m4t
ndng lrrong vi cdng sudt cao so vdi DCKDB'
2- MA hinh tPa d.Q Pho e&a dQng cd DB
M6hinhtoatlOphadrr.atr6ncdcphuongtrinhphacrlam4chstator
vd r6to. Vdi q > 2 (s6' khe/crr. c/pha) - c6c cuQn dAy d4ng phAn bd - ma
tr4n dien c6m chrira c6c thdnh phdn d4ng sin. chring ta s6 thidt lap cho
xem nhrl mQt
trrrdng hop r6to cU. c ldi, cbn tnldng hop r6to crJc dn c6 thd
tntdng hop t14c biQt riOng.
Ma tr{n tliQn c6m pha tl,l c6 d4ng (xem hinh 6'1 vh 6'2):
bcfd,Q,
L* L"f Lo.d, L*"
Loa
aL*
b Loa Lua La" LV Loo, Luo.
(6.4)
Lu" Ln L"f L"d, L"o,
[z]= cL*
f Lof Lv Lcf Ltr Lfo, Lfo,
4 Ld" 4o" L"d, Lfa, Lo,o, Lo,o,
Q, L*, Lbo, L"o, Lfo, Lo.o" Lo"o,
diQn cd
Cho tnrdng hop cuQn dAy d4ng phdn bd (A >D tdt cA cdc
a
otEu xurEN rcic oQ oONa
Loo = L"t + Lo +
co o6Ne ae
Lrcos(2l",)
Lut -- L"t + Lo + rr*"(2e",.
L""
:
247
*?!)
L"t + Lo + tr*"12e",.
-4)
(6.5)
"*=-++L"cos(2ln,)
.+)
L."
=
-+
"*
=
-+ * rr"o"(2e", -+)
Lod,. =
* r""o"(2e",
L"4, eosln,, Lbd, =,L"4
"o"(e",.
-+),
L"a, =2"r,
"".[e".
*
4)
CHUO'IG 6
242
[v]=[r].[;]
-+
(6.e)
(6.10)
lol= [t(e",)].[t]
(6.11)
fil=li",io,i",irl
trl= Diagt'"'G"i,'ol
(6.12)
[o]= [o",o6,o",0]
M6men diQn tU c6 thd drrgc tinh theo cOng thrlc sau:
Mdt=*=*'ft.
d(0") d(e",) *'
Ndu b6 qua beo hba til, nhAn (6.9) v6i
jdlil'
[if
(6.13).
(6.14)
:
trf .tvt = ["].[,].[r]' . *,(|jru.t;t ttl' )
*
Thenh phdn cudi
li
trinh
tt
c6ng sudt diqn
u u, =
Cdc phuong
f,.tit'. fr
T
=
f,.tif
t",.
)).tl.ry
(6.15)
Pdt
.;|[ro",
r].t,]
(6.16)
dQng hgc lA:
!dt,
pdT
_ M..
_M.:
d(0")
_a,
(€
d'q crtodQng eo DB
Dinhnghiav6ctdkhdnggranddngstatortronghQtgad0stator:
3- MO htnh
(6.18)
ii =f,xQ"+a.i6+o2'i")
lit4t kha", tu (6.10) vd (6.4), til th6ng pha a c6 giti tri li:
(bo L*io + L6i6 + L*i" + L"tT + L4i4 r L*,it,
=
(6.le)
srl dung c6c g16tri dien cdm trong (6.5) thay vio (6.19) ta dtrgc:
eo=
L"tn"ti"
+L
4
)+
P*lG'd
zo
|
d
o
nn<i
- )-
">
+
f,4
Rn(i"ez
s
Re(i L q,to,ei "' )
js-
)
+
L*Re(if eje- ) +
otEu xutEt't rdc D0
oQNe
co odua 4
oi =fr(o
Sr? dung c6ng thrtc tucrng
oi = L";;
*|t
"ii
*|!ii"'n-
+
NhOn (6.22) vdi e-io*, ta
6'
e-
ieq
=
a. (05 + o2
o+
tCr
243
.o")
(6.21)
(6.19) cho rD6,<D. trong (6.21), ta dugc:
Luifeio",
+
Ls,rleis* + L*,i[,eioo (6.22)
dugc:
(r* . Ir");:r-rn . |r,
(l:"-
**
)'
+
eii
+
L"a,i,* + j L*"i[, (6.28)
W6cto kh6ng gian til th6ng vA dbng stator trong hQ toa dQ rOto:
o-" =
[f"-r'e.,
i i, =i:e-ioq
(6.24)
Ttray
: (.c \- .Q o" =l4r *;.L.
li"+|tzi"+L"sii+L,+t'4+
\a).
(6.24) vAo (6.23):
Cdc
phucmg
trtnh pha stator trong
hQ tga dQ
jL"q"i;.
(6.25)
stator nhu sau:
r"io-Vo=-*
ruto
r"i,
-Vt
=
-#
(6.26)
-V" = -o?,"
dt
Chuydn sang v6cto kh6ng gian, ta
:e-ad["s-
6re -Vc =
-;
=
Nlrdn hai vd (6.27)
6i"-f"
-fi(6""i'*) -
,
"5o "-jo"'
ta
-eisu
ff - ir,6""ir-
io
(6.27)
c6:
=-ff-ir,a", ,,=+
Y = r"io* L**,
rl
c6:
=(io+io+i")t3
(6.28)
(6.2e)
Phrrong trinh (6.28) trrong tg nhu phrrong trinh cfra DCKDB, chl
lhr. & bidu thfc xdc dinh til th6ng (6.2b).
@-" = oo+irbot Oa = L"f4+tL6^i (Da^=Ld^iI+La,ii+Laii (6.80)
@q = Lsiq+Qqni
c.^
+
Qq^=Lo^id.+L*i[,
n-^
(6.91)
CHUONG 6
L6^ vd Lo^ dtQc gqi le cdc thdnh phdn d-q cria diQn cim til h6a'
C6 thd sfi dung c6c hQ sd quy tldi dbng r6to vi stator:
= !'o =*o
+=+n=Kai'f
ir" Ld^
4, Ld^
'l-= !"L=Kri
La^ '
ii
(6.33)
Qd* = La^id^; ia^ = ia +is +ia,
(6.34)
eo^ = Lq^iq^; iq^ = io *io, i i* = rl;i* + il^
B5o hba tt c6 thd xrlc dfnh bdi cdc him sd or-(i-) vi @q^(i).
Cdc him phu thuQc ndy hodc tinh to6n hodc do drroc'
Tridn khai cdc thdnh phdn d-q cria phtrong trinh stator (6.28):
V4
(6'35)
=r,i4*+-o,On
dt''
Vo =
r"ir*ff*''ao
(6'36)
trinh r6to trong h0 truc toa tlQ d-q:
<Dr = Lfis + Qo^
Vs = rsis .+;
C6c phrrong
o=
o
Phuong
=
r4,i4".+;
rn,io,
.+;
0
d"
= Ld,*d,
Qq, = LnJio,
(6'37)
!Qd^
(6.38)
* Ln*
(6.3e)
trinh mdmen drJoc xdc dinh nhu sau:
714
=
1
pRe(lo";: ) =
o
!n@ air.-
oia)
(6.40)
Park:
cu6i cirng, c6c bidn d-q lion ho v6i c6c bidn abc theo ph6p bi6n hinh
(6.41)
V" =Va + iVq =3,r" * aVo + a2V")"-is'" ' a = si2tcts
C6c bidn r6to c6
thd
quY
vd stator:
u,=t,,,=h, "o=h
Uo,,
ri=Ei t.aJ =@
r[. ue,r=@
, a,t
,n, =
,o,
x?;
(6.42)
(6.43)
<ti.++l
otEu xutEu
rdc oQ oQr,to co odua
245
eQ
M6 hinh dq c6 d4ng b$c 8 vA c6 tfnh phi tuy6h, tuy nhi6n cric hQ s6'
kh6ng phu thuQc vi tri (thdi gian). Gi4n tld dang tin hiQu truydn cria m6
hinh dq duoc trinh biy tr€n hinh 6.4.
1'r =
Lrt/lr
,0,=.'0,1*
r'0,=*
Hinh 6.4: MO hinh d\ns co ddns b0 ftnA Mnh d-q)
Ddi vdi dQng co DB dang kich tu nam cham vlnh cfrtr (PM) holc
tr0 (RSM), m6 hinh tr6 n6n iton gien hon: kh6ng c6 cuQn kich til
it = -rr"t. (blng 0 cho RSM). Chring ciing kh6ng c6 cuQn d0p (
cage) (t6r, = tdt = tqy = tqr = 0) (H.6.5).
Htnh 6.5: MO htnh dQng co loqi PM'SM ud RSM
Gidn tld truydn tin hiQu c6 thc sdp xdp lei thdnh sd d6 mgch diQn
hrdtrg tlrrong nhrr tr6n hinh 6.6.
orEu xu6r,t rdc oQ oQxa co odNa aO
247
Ddi vdi d6ng co PM (H.6.6) mach kich til dugc thay thd bdi ngudu
ddng kh6ng ddi iro, cbn trrrdnC hgp dQng co RSM thi giri tri ngudn ddng
niy
s6 bhng 0.
Ddi vdi trudng hop rOto kh6ng c6 dang ldng,
q.
=
rq,,.
=
-
(ia, = iq,- =.0)
,
6.2 TRANG THA| VAN nArun XAC LAp
d t""ng thrii
xric l6p cric di6n rip pha stator drloc xdc dinh bdi:
vot" =Jzv"o*fur,r
L
vdi
olr = const, n6n
i = r.2,5
(6.46)
vi tri r6to 0", ld:
0", =
Cltil j:
-ti-l!1;
r_t
(6.46)
= lardt= <rrr/ + oo
o, = oru = <llr Cho tralg th:ii x:ic ldp.
Srr dung cric
t,,:,.d.t
thdnh phAn dq cua di6n dp (theo 6.41) trong
T, =Va + jVq = VJf cos0o - jVJisinT"
hQ
toa d6 r6to:
(6.47)
Nhrr vAy, Va vir Vo khdng phu thu6c tho'i gian. C6 the thdy cdc
thhnh phdn ddng stator ia,i, c[ng kh6ng phq thuQc thdi gian. Do
dldt= 0 (s - 0), tU cdc phuong trinh (6.37), (6.38) cd thd suy ra rXng
i6, = iq, = 0 vA is = ilo
=+
rf
=
const
.
Gizin d6 v6cto pha theo (6.35), (6.36) dudc trinh bdy tr6n hinh 6.7.
(6.48)
% =l;i" +7t0,.(r.i (rJ,. =t-u.
(ot
d axis
CHUdNG 6
6
xdc ldp, tdt ch c6c bi6-n trong m6 hinh pha - kh6ng gian (hodc de) ld cdc dai luong mQt chidu. Do d6, viQc s& dung m6. hinh d-q cho didu
khidn tdc dO lA hgp ly.
6.3 orEu
KHTEN vAru
rO'c
siuc
cAcH THAv sdl rAru s0'
Mdi li6n hQ gitra vQn t6'c vd tdn so'rdt chdt ch6 trong dQng co ddng
tt tlQng rdto c6 tinh mQt chidu (hoac pM).
bQ do srl'c
n=L; or=ol;
er=(D,
lp
rc.4s)
vi6c didu khidn vQn t6'c blng cdch thay ddi sd cdp cr,.c p thrrdng
kh6ng dugc sr? dung. \h thd, vi€c thay ddi tdn s6'ld didu bdt buEc. Tuy
v{y, vdn dd cli6u khidn cdc hQ truydn dOng d0ng co ddng bo dd dat drroc
ddc tinh xric lQp & quri d0 (dac tinh dQng) thfch hop vdi cric rlng dung
kh:ic nhau clrroc ddt ra tl6'i vdi vi6c rli6u khidn tAn sd trong m6'i tuong
quan vdi di6n dp stator % vd ddng kich til i/.
vi dq 6.r. Hc s6'cdng sudt blng don vi vd tr} th6ng stator kh6ng ddi.
Gi6 sr? ta khrio sdt dQng co ddng b0 kich trlr vdi c6c th6ng
=660V
%n
(CliQn
6p dAy, hi€u dUng, n6'i
y), /,, =#,
,12
sd:
4, =0,016C),
L4=2L, =0,0056H, L"t=O,lLa, o\ =2n6Orad,/s,p =2.
Xric dinh:
.
Gi6n dd pha - kh6ng gian d xdc l{p vdi hQ sd c6ng sudt blng
(9r =o).
.
gid
tri
.
.
mri'c
Tinh cdc gi6tri
dinh mr1'c (I.,,).
Tfnh giri
tri
l,ia,io
m6men
cho trrrdng hop HSCS =
1vd dbng pha
1
c6
khi g, = g .
Tinh vi v6 d4c tinh cd cho trrrdng hop tir th6ng stator bxng dinh
vd 0,5 Od^ khi thay ddi tdn sd vh di6n dp stator kh6ng ddi.
Giai
a) Gidn dd y6u cdu c6 thd suy ra tU (H.6.Zb)
vdi
gr =0
orEu xutflN rdc oQ oQNo ca o6Ne eO
249
Hinh 6.8: Gidn dd uicto - pha khi f/SCS bdng
b) TrI hinh 6.8 ta c6:
%=t"r,+o"@"
6" = Oa + i@c = Laia + Lo*i, + iLoio
Vro = arL6^iy; (ia = io = O ); or" = olr
=887,92V; i"
=
I"nJ-z=ry=booA
1
(6.1.1)
(6.r.2)
(6.1.3)
(6.1.4)
TU (6.1.1) tU th6ng stator
V -ri
(D'=.s=
-
do
dinh mrl'c ld:
537,92-0,016.500
o.
=
d".
2n6O
=1.406\Vb
(6.1.6)
cos 6
(6.1.7)
Loio = @".sin6
VQy
<D"fg6 =
(6.1.8)
Lo.i"
+ /s6
+
- =Lo'i"
o" -o,oo28x5oo=1
L,4O6
i" 5P
-ra =rq
=E = lz
od =(Do
@6 =
Ddng kich
=*=
'rl2
(6.1.5)
6=4bo
=354.61,q,
t'n*6
',12
=o,99ZWb
Lai6+ La^i1
(6.1.e)
(6.1.10)
(6.1.1 1)
(6.1.12)
til is (quy vd stator):
0,
997
-
0,
0056 x (-354, 61)
0,0056(1- 0,1)
=591,82A (6.1.13)
250
CHU^,IG 8
Mdmen tliQn
tt ld:
3
A =|n(aaiq-aqid
) =!x2x(0,99?x3b4,61-0,99?(-gb4,6r))
2
= 2121Nm
(6.f .14)
Chf y khi cosgl =1, phrlong trlnh mdmen (6.40) c6 thd biCu di6n b&i:
a
(6.r.15)
=|e@,r"
TrI thdng stator vi ddng stator li hai vdcto vu6ng g6c nhau, tUdng
trr nhrr tnrdng hgp dQng cd DC. H€ quA rrit ra ddi vdi tnrdng hgp tU
thdng stator kh6ng ddi O" = const, m6men tt lQ vdi dbng stator.
Thay ddi tCn sd
ft
<ol
=(+
vA
gifl
Qs
=const, cosgl =1
li
didu kipn tdi
ddi vdi qud trinh didu khidn tdc .t0.
Ddc tinh m0men/ v{n tdc c6 thd suy ra tU (6.1.1) vA (6.1.15) blng
cdch khfi tli dbng i"
.2M
" 3po"
l^ =-
"*2r"M
3po"
v^ = <o-o-
Do
cur
(6.1.16)
(6.1.17)
=co,, di6u khidn t6'c tlO c6 nghia ln didu khidn tdn sd.
D{c tinh co lA drrdng th8ng gi6'ng nhrr df;c tinh cria dQng co mQt
chiCu kich tU dOc l4p. V4n tdc kh6ng t6i lj tudng (khi M - 0) lA:
t-
=%
o"
Cho trudng hgp tU th6ng vd
diQn dp c6 9;16 tri itlnh mfc, tdc dQ
dQng co sE ld tdc d0 ddng b0. V€n
tdc tr6n tldng b0 chl c6 thd tlat
tlrrgc blng cdch suy giArn til th6ng
grdng nhu trudng hgp tlQng co DC
(H.6.e).
thd lim viQc trong
.16 vdi khA ndng tl6o chi6u v$n tdc
blng cdch dAo tr$t t{ pha [(a -+ c
+ b) thay vi (a + b + c)J stator
DQng co c6
(6.1.18)
otEu xutEtt rdc oQ o2tto co odva
tri
25t
W
Dd gifr hQ sd c6ng sudt blng 1, ddng kich
m6men (H.6.9).
Vt ds 6.2. He sd cdng sudt sdm pha
vi
tt
cdn phdi tnng theo
gidL
tU thdng stator kh6ng ddi.
Kh6o sdt tlgng co ddng b0 d4ng r6to kich tr] v6i cilc th6ng sd nhrr vi
du 6.1.
Xdc dinh:
- Gi6n dd pha - kh6ng gian vdi
g6c l€ch
pha gr =-72o
(hQ sd cdng
sudt sdm pha) d trang thdi xdc lflp.
- Tinh
cdc gid
tri i1,i4,io
cho trudng hgp ddng dinh mtlc va
9r =-12o '
- Tinh tir th6ng stator 0., thAnh phdn d-q cria til thdng
Q.
vd
m6men diQn tU tudng fhg.
- Tfnh gi6 tri
dbng kfch
til cho trrrdng hop * =L*o*
vA
ol. = 2160 rad,/s.
-
V6 d4c tinh co (girln dd M(ar)) cho trudng hgp
@. =O"u_
@"
=it,o-
vd
vdi q =-I2o
Giai
GiAn dd pha khOng gian hinh 6.7b c6. thd sfi dgng
(sdm pha vd drrgc trinh biy tr6n hinh 6.10).
o"
I
vdi 9r=-120o
252
CHUONG 6
Tt hinh 6.10 ta c6:
(6.2.L)
% = r:,r" cos 91 + crr@"
Mdmen drroc tinh nhu sau:
33
;Pas.zs.
537 ,92
-
cos o =
;P<DsIs
500 x 0,016 x
(6.2.2)
cos gr
cos(-12')
2n60
= 1,4068 Wb
(6.2.3)
14
=!x2x7,4068x500x0,978
2
jq = i" cos(6+
= 2063,83
Nm
(6.2.5)
lgr l)
(6.2.6)
Loio = <D".sin63
SUY
sin6
cos(6+ | gr
fa: "---r1-----
Lni,
l)
6=39o (gid
vi
thd:
_0,002gxb00
=g=-ia=0,99
os
1,4068
tri
6=45o
khi
cosgl
(6.2.7)
=1 trong vi du 1)
iq =500xcos(39o+12o)=413,66A
(6.2.8)
ia = -500x sin(3go +L2o) = -388,57 A
(6.2.9)
<Dn
1"
'
(6.2.10)
= Lnin = 0,0028x314,66 = 0'881Wb
Od = O"
vA:
(6.2.4)
' cos
6 = 1,4068' cos 39o = 1, 09388
=Qa-Laia
Ld^ -
Wb
(6.2.11)
1,09388-0,0056(-388,57)
= 648,78A (6.2.L2)
0,0056x0,9
Gien dd tl[c tinh c6 M(<o) c6 thd suy ra tU (6,2.1) ud (6.2.2) dudi dang
% =0"o"
.H
(6.2.13)
D{c tinh gAn gidng cho trudng hop vi du 6.1 vdi cosgl=l. Didm
kh6c biQt d ch6 vdi cr)ng giri trf dbng stator, diQn, 6p stator vA t6'c d0,
mbmen dat drroc c6 gi6 tri thdp hon vd dbng kich tU c6 gid tri cao hon
dd cung cdp g6c he sd c6ng sudt gt < 0. Gid tri g1 = -120o c6 thd drroc drr
loai t6i kh6c nhau ndu ddng kich tt drroc hiQu chinh li6n tuc.
DAy ld phrrong phrip phdi hop thay ttdi tAn sd trl th6ng stator - ddng
kich trl dang drroc sfi dung cho cdc hQ truydn dQng clQng co ddng bQ r6to
trrl cho
c6c
oEu rcnEN rdc oQ oQNa co o6Na aQ
253
Vi dq 6.3. DQng co PM-SM, vdn hdnh vdi i6 khdng tldi
DOng co ddng b0 kfch tr) nam ch6m crlc dn c6 c6c th6ng sd:
% =180V (tri hi6u dung r{p ddy), La=0,4; Zc =0,05H, G=1O, tri
hiQu dung rip dAy khdng tAi 6 nn = 1500 v/ph ( ft = 6OHz), %, = 180 V.
Hdy xric dinh:
o TrI th6ng @pjv,;
. Dac tinh co M(ol) khi id = 0 , ja = tbA vd t6'c dQ kh6ng tei li trrdng
trong c6 3 trrrdng hop, tt th6ng stator vA m6men, vdi io = 10 A;
. V6 m?ch tudng tlrrong d-q 6 x6,c lflp vA drra vdo tdn hao l6i trong
md hinh.
[ilal
DiQn dp kh6ng
tai
Von chuydn sang dang v6ctd kh6ng
gian
v""J,=_;
lsoJt
v*=-T
=L46'7Y
Theo (6.1.2) d vi du 6.1:
(or),0=o - La^ .ip.-
@r*
o
%, =0"'La^'ifr=arQpM
Do
-v*
= o,B89wb
0)r=t!^u!^o
2n6O
Qa = Laia
+Qpu;
(6.3.1)
(6.g.2)
(oo);o=o =
epu
V"o:
Qn =
Loin
(6.3.8)
(6.3.4)
(G.a.b)
(6.8.6)
M6men di6n tr] drroc tinh theo c6ng thrfc:
M
=|naaia-eqi)=f,ol*r* +(La-L)id)iq
thdnh phdn d-q cria cliQn 6p, vli d/dt
Va = rria - co"Oq
Thay io tir (6.3.7) vdo (6.3.8), ta c6:
C6c
=0
(6.8.?)
:
(6.3.8)
vl +v] = V: = r! Gi + ip + 2ro,r"(a oio - Q ni) +
+<rl.l{toio+apy)2
ho{c: vl =r!il+(42
.
+
6;iL?
'
+(Lnio)21
(6.s.9)
iv ul
o" =---l-_----=+(t-o t
l*r*
+19^ .M +a?(Lri, +e,.)2
-
;tof"
(6.3.10)
254
CHWNG 6
Tdc t10 khdng tei l)t tudng co,
li:
(M =;
(6.3.11)
'"=7-'?ffi
Laia + Vpu
Ktri
ia = 0
(c,r,,)6=o =
Khi
id =
i6
= Bz7,larad./s
(6.3.r2)
= 984 rad/s
(6.3.13)
-5A
(<,ro
Khi
#= offi
|r=-sa
=
ffi
=$tr
(*),oo=.ffi
' (o,ob.b+o,B8g)
=229tadls
(6.3.14)
Nh6n x6t: Khi ia <0 c6 |Shia ln higu ting khr? til. Tuy nhi€n, bidu
thfc (6.3.7) cho thdy ld do Za <Lo n6u chl iu<0 thi m6men vdn c6 gid
tri drrong. Trudng
hgp nAy kbm theo s\r suy giAm tr} th6ng stator:
(@");o=6 - od = L4i4 + Q pp = {),05 x 5 + 0, 389 = 0,149 wb
(6.3.15)
ia=4
(<D");o=e = 0,05x5+ 0,389 = 0,639Wb
(6.3.16)
ia=Ee
M6men
khi
id
=0, -54,+54, iq=LOA c6 gi6 tri
lA:
@)iXXoo=lnaeuh =9x2xo,389x 10 = 11,67 N.m
,*,
'
E=:t=
9 x z x (o' e89 + (o' 05 -
0' 125) x
(6.3.17)
(-5)) x 10 = 22' 92 N.m (6.3. 1S)
@)*=lto=|x2/(.,389+(0,05-0,125)x5)x10
=0,42N.m (6.3.19)
Cdn ph6i trdnh tnldng hgp ia drrong vi chring sE lAm tdng gi6
th6ng vA gi6m grd
t4
MO hinh d-q I
(6.3.8) vi hinh 6.11.
td
tU
mOmen mQt cdch ddng kd.
tr4ng thdi x6c l6p (s = 0) phAn dnh phuong trinh
otEu xutEv rdc
&
afiua co oduo e0
"l
255
ro,(L6(i6-i6ps)+Opy)
<,rrLo(io-iqre)
Einh
6.11
Tdn hao l6i li6n quan ddn thdnh phdn trl th6ng chinh vA ta c6 thd
ld chring sinh ra bdi tU th6ng stator. Tdn hao ndy drrgc dua vio
md hinh blng cdch mdc song song vdi sric diQn dQng mQt diQn trd rpB.
giA thiC't
Vt dq 6.a. D0ng co ddng b0 tir trd d tr4ng thdi xdc lQp.
DQng co c6 thdng s6: La=l.:OLq =0,1H, p = 2, r"
Hdy xdc d!nh:
a) Gidn tld pha - kh6ng gian.
b) Mdmen cgc dai rlng vdi gid
trudc.
tri
dbng stator
=1O, fr=60ft2.
vi tir th6ng stator
c) ThGm mQt nam chAm (PM) dgc theo truc q dd gidm
q. Hdy v6 lqi giAn dd pha - kh0ng gian vi binh lu$n.
finh
CbpM
=
m6men
d) Tinh
til thdng trgc
khi ia=3A, ic=15A kh6ng c6 vA c6 tir
-Loio.
cho
th6ng
otr
til
th6ng stator dd
sinh ra mdmen tUOng rlng.
Giti. GiAn dd v6cto drroc x6y
dgng drr.a tr6n hinh 6.7 v6i is =o
vd, La
,,
Lo, drrgc trinh bdy tr€n
hinh 6.12.
Bidu thtlc tfnh
(6.3.7)
mdmen
(vi du 6.3) vdi if = 0
vA
Ld >> Lo iltgc vidt lai nhu sau:
Hlnh
6.12
u =|n@a - Lq)idiq
(6.4.1)
Phrrong
trinh
diQn dp (6.3.8) (vi du 6.3)
Vt
trd thAnh:
Y
256
CHUONG 6
TrI th6ng stator @" vh dbng stator l":
(Ds
=(Dd*"/@c = Loio+ jLoio
i'=ia+jio
M6men
cr,rc
(6.4.3)
(6.4.4)
dai fng vdi dbng stator i"
:
i"=rfffin
(6.4.5)
AM
_-0
(6.4.6)
dia
Sau
khi khfi in ta
cd:
io, = io, = i"
I
J2;
Mi
=
3
|n@a
-
.i.2
L).;
ra, T=45o tr6n hinh 6.12.
Ndu i" = jo (dbng clinh rnrlc) i4 = i"n lJ2 ,
(6.4.7)
Suy
vi ddng i6. qu;i ldn
so vd'i dbngpha
rrr6y di6n
bi b6o hba ning
dinh mrlc kh6ng Lai i"lJ-z, ngoai tril
vdi iolio>0,707. Di6u ndy dan
ld cuc dai thi chi stir dung cho cdc
trrrdng hop dQng co c6 c6ng sudt rdt nh6
ddn he qud ld tld gi6 tri m6men/ampe
trrrdng hop m6men thdp hon 50 - 6OVo dinh mr1c.
Mit
khric, rlng vdi tr} th6ng stator cho trrrdc (6.4.3), m6men crrc dai
dat drroc:
iaaLa =irr;Ln
=A,lJ2
-303
Mq
=|p(La-"r)
ffi
(6.4.8)
(6.4.9)
Trong trrrdng hop ndy g6c gitra cric thdnh phdn d-g crja tr] th6ng
giri
tri
c6
45' (H.6.12).
Th6m vdo nam chdm PM vi.o truc o
@o = Lnin
-@prrto; Qa = Laia
(6.4.10)
vdi Qpyo>Lo.iq^^* ald trrinh khft tU nam chAm. Bidu thfc m6men trd
thhnh:
ida
cis,a
=iai
=iolJi;
M =X.ol<"r-Lq)iq+arnolio
(6.4.1r.)
Trong trrrdng hop ndy, ild dd,o chidu rndrnen (dd hdm trii sinh) ddu
i; cdn ph6i thav ddi trong cdc he TD didu khidn tdc d6. Gidn dd
otEu rcutEN rdc oQ o6No
co
o6Nc
so
257
(rrr
vi
Hinh G.IS
chd )t cho chd tlQ d6ng co 6 < 0 (v6cto til th6ng tr6 pha hon truc
h6 sd c6ng sudt teng theo m6men.
M6men vd tir th6ng stator cho 2 tnrdng
(M)*rrn=o
a"
(M)a,*,*o
ho.
=|n{ro - Lq)idiq =t*rx 0,1x,t -,x
=
,uE|
'
=|,,r,.
41;
-'
=
^lo,r'
V
,e,
)
e,1,,ru]*,
[0,t,.<r-fii.rs*
p:
3,15) =
*(!,1b)'
\10
d)
r|.rsN.m
= 0,385
wb
= 13,15N.m
(6.4.12)
(6.4.13)
(6.4.r4)
@"=Laia=0,1.3=0,3Wb
Nam chAm vinh cfiu (PM) ddt vd.o truc q ldm tdng m6men l6n
vd gizim giri tri tt th6ng di I\Vo.
107o
6.4 HE TRUyEN 00Nc DONG c0 odruc e0 pM.swt vA RSM
6.4.1 Gidi thiQu
D6ng co ddng bQ PM (kicti trl nam chAm viirh criu) vd RSM (tir trri)
ph6'i hop vdi cric bQ nghich lrru dp PWM trong cric h6 truy6n dQnS didu
khidn tdc d0.
Ho truydn d6ng d6ng co pM-sM dtroc siir du'g khei r6ng rai vd duoc
sr? du'g cho cd.c r1'ng dung c6 y6u cdu vd dac tinh cao. H6 truydn
dQng
RSM thi c6 thi phdn kh:i nhd, c6 thii duoc srl dung cho cdc rl'ng dr;ng
CHUONG 6
258
6.4.2 HC truydn dQng dQng co ddng b0 kich trl
(PM.SM)
nan chAm vinh crlu
PhAn loai:
C6 ba cdch phdn loai h0 truydn dQng PM-SM:
a) Theo d4ng dbng diQn:
sin
Illnh 6.74: Didu khidn d.dng dgng chrt nhQt l.r.oQc dqng
hQ truydn
_ Didu khidn dbng dang chfr nhft (H.6.14a) - cbn ggi ld
dOngDCkhOngchdiqu6t(BLDcM-BrushlessDCmotor)v6iq=L,
c6 d4ng trOn hinh 6.2b.
- Didu khidn dbng dang sin (H.6.14b) - cbn goi la hQ tquydn
q 2'
AC kh6ng chdi qu6t (Brushless AC motor) vdi 2
(encoder):
b) Theo srJ hiOn diQn cfia cdm bidn 4 tri
otEu xutEN
r6c oQ oervo co o6va
w
c) H0 truydn tlQng ddng dang sin (Brushless AC) cdn c6 thd
phAn loai theo phrrong phrip didu khidn:
drroc
- Didu khidn vO tr.rdrrg (V lf)
- Di6u khidn v6cto (ddng hodc ddng vd dp)
- Di6u khidn trr/. c tidp m6men vd til th6ng (DTFC)
chri )t ld gidn dd dbng diOn stator - cht nh4t hay sin (H.6.14) - cdn
phdi drroc rldng bQ h6a vd'i vi tri r6to:
su tldng b0 h6a c6 thd drroc thuc hi6n blng cdch rlidu khidn trang
thrii d6ng vi ngdt c:ic kh6a cria b6 nghich lu' pwM theo m6'i quan hQ
vdi vi tri r6to 0,".
nhlm muc dich bn gi6 tri luc diQn tr} tdng theo
van t6c vd bir rt6p rl'ng tr6 do cdm kh6ng cfia mdy di6n khi thay ddi dbng
chuydn mach, pha s6 cluoc ddi vd phia tnrdc mQt g6c a, vd gi:i tri niy
s6 tdng theo van tdc. Dang dbng diQn tlrroc thidt ldp th6ng qua c6c kh6u
MQt crich tdng qu:it,
didu khidn ddng.
Phuong phdp tlidu khidn ddng dang chtr nhat thrrdng tlrroc ding khi
c tliQn tir c6 dang khdng sin (hinh thang), e = l, cdc cuQn d6y stator
dang t{p trung. Phuong phdp ndy nhlm gi6m cric xung dao dQng mOmen
vd c6 rru thd khi qfl dung cdm bidn vi tri clon gi6n (hodc bQ rrdc lugng).
Didu khidn v6 hddng (v /f) kh6ne dr)ng c6m bidn cho phuong phdp
tlidu khidn ddng dang sin duoc trinh bdy tr6n hinh 6.15.
lu.
Hinh
6-75: Didu
khidn
vlf
cho PM-1M (hodc RSM) udi khdu
bi
tdi
CHUANG 6
260
tai
DO gia tdng g6c
gi:i
tri 4f.
dd
bi
AO duoc rrdc
tinh vd tdn sd cl4t sE dtroc t[ng l6n
sd bidn thi6n m6men vd gifr cho dbng dQng co ttdng b0
vdi r6to khi qud d0. R6to dang ldng dugc srl dung tld d4p
tft
c:ic dao
bi gi6i han.
phrrong phrip didu khidn v6 htrdng thich hop v6i c6c rl'ng dgng c6
y6u cdu ddc tinh tlQng khdng cao vdi rru tlidm v6 tinh tlon gi6n cria hQ
(drip rlng
didu khidn. Edi vdi cdc tng dr;ng yeu cdu dic tinh clQng cao
(H'6'16)'
nhanh) thrrdng sfi dung phuong phrip tlidu khidn v6cto
tlQng do sudn tAn sd
(May phtit xung)
encoder
Van tdc dAt
hodc udc tinh
l- vdi cAm bidn vi tri; 2- kh6ng cdm bidn
Hinh 6.76: Didu hhidn udcto
r6to tlrroc tlo blng cAm bidn hodc ddc tinh (cho
lim tin hieu
cric hQ truydn clQng kh6ng ddng c6m bidn) vd drrgc sfi dung
Vi tri vh tdc
dO cria
hoitidptAcaO(co,)vdg6cquayv6cto(0,')ddtaocdcgiftricl4tcria
hd
dbng cdc pha stator i;, i;, i:. HQ didu khidn vbng kin hoic vbng
pWM drroc srl dgng tld thidt l{p dang ddng di€n (hoac tlien 6p) drrgc girt
ddng bo vdi r6to. PM-SM dugc tlidu khidn theo m6 hinh d-q trong
tructgad0r6tovdttfongt{nhudQngcoDC6tr4ngthriixricl{p.
Thidt tap mdi tudng quan giila thdnh phdn fi vd il c6 tdm
hQ
quan
khidn
trgng tldi vd,i viQc tdi rju h6a theo ti6u chudn ddt ra. He thdng didu
ph6p d4t
v6cto phri'c tap hon nhidu so vdi didu khidn V lf, tuy nhi6n cho
cluoc tl6p rlng dong cao hdn nhidu (didu khidn nhanh m6men).
Dd don gi6n h6a viec rli6u khidn dQng co, phuong phrip alidu khidn
vd trl thong OTFC) cho DCKDB drroc m6 rQng rrng
otEu xutEN rdc oQ oQNa
co
o6Na aO
26L
vdn dd didu khidn trrrc tid'p til th6ng stator vd m6men drra v6 vi€c
gidi quydt bdi torln thidt lap bang quy luQt d6ng cdt kh6a bdn d6n crja b6
nghich hnr 6p PWM (trinh trr v6cto kh6ng gian di6n 6p). GOc quay v6ctd
0". kh6ng cAn x6c dinh trong trrrdng hop ndy, tuy nhi6n cdn sfr dung
khau quan sr{t ttr th6ng vd mdmen. Trong hQ th6'ng sensorless, tdc
r6to cring s6 duoc rrdc tinh.
dO
encoder
Van
Hinh 6.77: Dilu hhidn trtrc tidp
tt
th6ng ud m6men
Di6u khidn ddng dAng chrt nhft (hQ truyin dQng BLDCM)
Di6u khidn ddng dang chrl nhAt duoc ri'ng dung cho dang s6ng sfc
diQn d6ng cfia dQng cd PM kh6ng sin (hinh thang). Dang s6ng ndy d{c
trung cho cdc cuQn stator tAp trung (g = 1). Dd gi6m c6c xung dao dQng
6.4.3
cfia mdmen cdn sir dung dang ddng diQn chr1 nhAt.
g firAng erta d.Qng co BLDCM
Vd nguyOn tic bd mdt cria nam chAm vinh cfru trAi ra theo g6c pha
7- Dg.ng s6ng
crpy nh6 hon 180o (H.6.14). Hai ngrrd'ng gidi han cfia a", Id.2nl B vA r.
Gi6 sfi nam chdm vinh cfiu sinh ra trl th6ng khe hd kh6ng khi dang chfr
nh{t phAn bd theo dpM = n (1800) (H.6.18a). Srlc tt d6ng pha stator
drroc gid thidt c6 dang chrl nh{t (tuong fng vdi q = 1). \ v{y, tt th6ng
trong cuQn stator QpM(0",) bidn thi6n tuydn tinh vdi vi tri r6to (H.6.19b)
vd srlc di6n dong pb.a Eo cd dang chtr nh6t tudng rlng theo vi trI r6to
(H.6.18c).
Cho trudng hop g6c vudt trudc do = 0 (H.6.14) - cdc ddng pha ddng
pha vdi srlc diQn d,Qng (io,E") d chd d0 dQng co (H.6.18.d).
CHUONG 6
262
BsPM
a)
Che d0 dQng cd
Chd d0 mdy phdt
Hinh 6.18: Gitin d6 tl!' tudng) cho BLDC
d Uat kj, rnQt tho'i di6m .do, n6'u gid thidt chuydl rn4ch trlc thdi,
chi c6 hai pha dan diQn. vi thd, chi c6 213 rram chdm vinh crJu duoc sir
dung, tr] th6ng trong l6i phia dudi l<in hon 50ol giri tri cdn thi6't' Mat
khric, ndu dbng ctiQn k6o ddi 1800 (v6'i ba pha d6n cing rnot hjc) cho
giri tri
nam chdm 120o, tdn hao d6ng s6 IdD hon can thi6t ,oE, vdi ciDg
m6men.
Cho nam chAm rQng 120", sti drlng kidu ddu ddy dang tam giric; do'i
vdi nam chdm rQng 180o, sf dung ki6u dau dang sao. Ed gizim zirth
htrdng cria trlt th6ng tzin gila cdc nant cham canh uhau d6 r6ng thong
thudng ctia nam chAm la 150" -160o.
TrI thdng trong cuQn stator )'""t drroc bidu di6n boi:
(2.\
oopM(e", ) =
Giri
tri
[1
- :e",.
(6.50)
JoPM
cuc dai cria t'U th6ng cho nrQt pha lh:
(6.51)
Qpu =W1B:spIarL
vd'i:W1- sdvbng dAy m6i
pha; t - budc cuc til: L - chi6u
Sfc di6u dQng Pha E,,;
ddi
orEu
tri
xuErt rdc oQ DOib cd odNa
eO
Do hai pha dan d bdt ky thdi rlidm nao n6n m6men
khdng ddi.
M =2Eoi4"
epu
+
olr= +.
n
.
p. ia"
lf
tudng c6 gid
(6.53)
Gifra hai lAn chuydn mach trlc thdi, ddng pha kh6ng ddi (td ia")
=
phuong trinh diQn dp lA:
V4 =2r"i4"
*2Eo =2r".i4" +lxLpra .a,
vi
(6.54)
Tir phuong trinh (6.54) vA (6.b3) ta c6:
(t-L\
' =o)-'ol
M"^)
o)-
vdi '" =+ #i
Mo* =1,'*r*'o'i^^;
i, =*
(6.55)
D{c tinh co lf trrdng c6 dang drrdng thEng (H.6.20) gi6hg nhrr dQng
co DC kich tir nam chAm vinh cfiu c6 chdi qu6t.
a)
Dt
b)
D4
Hinh 6.79: Qud trinh ddn crta pha a ud b
d chd d0 forv, phrrong trinh cho a + b (H.6.19a) lA:
2r"i+2f,"fi+ E" - Eo
(6.56)
Eo-Eb=2Eo-Eo=colgt
(6.57)
Va =
,
CHUONG.6
264
GiAi phrrcirig trinh (6.57) ta drrgc:
ie1 =va
=
E"(,
2r"
t
-
;'11*,.,""-'f
(6.58)
J
Dd cho ph6p ddng t6ng thi Va, Eo. Vugt qud mQt gi6 tri tdc d0 nio
tt6 thi Va fi6 n6n nhd hoo E, vd dbng kh6ng cbn didu khidn dang hinh
6.18 dugc nf,a. Gi6n tld ddng trong trudng h_gp ndy c6 d4ng xung don'
Khi 6 chd dQ toff (diode D1 vd Dn d6n, hinh 6.19b) phUong trinh
tli€n 6p tlrroc vi6't ld:
o
=2r"i+zL"!r+@"
-il.+lid.t
(6.5e)
+vs.
, v"o ld dien dp tq dien d thdi didm kdt thric khoang
thdi tlidm bdt tldu khoAng thdi gian ng6t.
Nghi€m cria phrrong trinh (6.59) vdi truc thdi gian
thdi gian d6n,
hoqc d
iG) =
-H#o-crrt'
f'=f
.irr.y r- ;-* .*.n-ort' sin(otf '-
0)
*
forv
'
ld:
(6.60)
(t'r
!\o
;;
Hinh 6.20: DQc ttnh co fi tu&ng cho BLDC
V4n tdc c6 thd giAm vA dAo chi6u blng crich gi6m gi6 tri vd d6o crr. c
tinh cria itiQn 6p mQt chi6u cdp cho m6i pha tlQng co blng cdch didu
khidn d6ng c6t trong bQ nghich hnr kidu didu bidn d0 rong xung (PWM).
-.
oEu rcnEN rdc oQ
oQNo
co o6No aQ
265
Gi:i tr! tr} thdng m6i pha crrc dai (or*) c6 thd gi6m blng c:ich didu
khidn vudt trudc ddng cliQn trong m6i pha bdi g6c u^+O. N€u do=fr,
cdng sua't diQn trl trd n€n Am vi chd dO ham tdi sinh c6 thd thuc hiCn.
(H.6.18e).
2- He thdng didu khidn d.bng d.qng chrt nhQt
HQ thdng clidu khidn gdm clQng co BLDC, nghich luu PWM, khAu
didu khidn v4n tdc vd dbng diQn, c6m bidn vi tri (tdc tlQ) hodc khAu rrdc
tinh cho he tlidu khidn khOng cdm bidn vd cim bidn dbng (H.6.21).
Hinh
6.27: HQ thdng
di6u khidn dQng co BLDC
vdi dang s6ng vd
trinh trr drroc trinh bdy tr6n hinh 6.22. Tr6n hinh cfing trinh bdy vi tri
d4t (6) cfia c6m bi6h phrit hi€n tidp cQn gdn vdi g6c oo = 0. Cdc cAm
BQ nghich lrru drroc ttidu khidn dd cung cdp dbng
bidn tluoc
kf
hiQu p(a+,
a-, b+, b-, c+, c-).
Vdi hai pha ddn cfia stator, c6c v6cto tlien rip (H.6.22) sO nhAy cAp
60o cho m6i IAn chuydn mach bQ nghich lrru.
Dd ddo chidu tO'c dQ, cric dia chi (IGBT) cria cAm bidn tidp c4n gAn
drroc ddi di 180o (p(a+) -+ p(a-); p(b+) -> p(b-); p(c+) -+ p(c-)).
G6c c" c6 thd tdng khi tdng tdc tlQ nhXm gi6m bdt tr) th6ng dlnh
cfia nam chAm vinh crlu trong pha stator vd nhrr v{y sinh ra m6men
nhidu hon, khi diQn:ip bi gidi han d v{n t6'c cao.
St? dung phdn crl'ng tudng tqr tr6n cfing c6 thd tao ddng c6 d0 rQng
dAn di€n.
_Y_
CHUONG 6
266
t)) QgQe QsQ'
Hinh 6.22: a) Trinh tu ddng; b) Kdt ndi pha
a) O@@@@@
Khdu hiQu ehinh d.bng dqng tr7 (hysteresis)
Dd tlidu khidn ddng DC chi cdn cl4t 1 cAm bi6n ddng d khAu mQt
chi6u, viQc phdn bd dbng diQn cho sdu nh6m hai pha d thdi didm ndo d6
drroc kich bdi c6m bidn vi tri.
Khi ddng trong mQt pha du^oc hinh thdnh, n6 s6 td,ng gi6 tri cho
ddn khi dat ngrrdng tdi da i-"*. d thdi didm ndy, pha tluoc ngdt cho ddn
lric dbng gi6m xudng ddn ngudng imi,. Thdi didm d6ng vd ngdt ton,toff
drrgc x6c dinh trdn co sd ddi tr5: 2(i*u* -i-r,) (H.6.23).
3-
lmq
lmin
t"n
I!
di6u khidn ddng
Ta khAo s6l cilc phrrong trinh dQng cd cho chd tlQ d6ng (r61y) vd
ng6t 1to6) vd'i Q1 vi Q+, DrDn d6n (H.6.24). Ddy ld trrrdng hop nh6m o
Hinh
6.23: NguyAn
+b-d6n.
;o.r=h; t=Jtj-a7;p=tan-r dro)
(6.61)
Bidu thrl'c xdc dinh m6men:
y =(8"-E)i(t)
(rlr
p
(6.62)
otEu xurEu r6c oQ o)uo
co o6Na aQ
Oi6u khidn v6ctd (didu khidn ddng dgng sin)
Didu khidn v6cto duoc sir dung cho cA hai loai r6to (H.6.1b
H.6.2b) vdi cdc cuOn aay stator dang phAn bd (q > 2).
e.a.+
vA
M6men duoc xdc dinh theo muc 6.1.3:
u
Phttong
=
lnla rrio +
trinh
(La -
Lo)ia4l
(6.61)
v6cto khdng gian:
7" = 4j" *$*"rr"o"
,
T" =Va+ jVo; i, =ia +jio; <D" =<D6 + jon
Qa = Qpu + Laia; Qo = Lrio
(6.62)
(6.63)
(6.64)
Th6ng thudng, La 2 Lo vd nhu vdy thdnh phdn thrl 2 (ph6n khdng)
cria m6men chi drrong
khi
id < 0 (H.6.24).
Th6ng thrrdng trong phrrong phrip didu khidn v6ctd, r6to kh6ng chfa
cuQn d{p vir nhu v4y kh6ng c6 mach r6to vd hQ qui trttc tidp ld kh6ng
cdn thidt lQp mang trich dbng, ngugc lai vdi trudng hop tl6ng co khOng
ddng b0.
Hinh
6.24: Gid,n d6 udcto pha crta PM-SM udi ddng ia <O
DQng co PM-SM drroc didu khidn trong hQ toa dQ d-q vd. cdc thdnh
phdn ddng d,4t i;,h (hoic diQn dp) s6 dr.roc chuydn sang h0 toa dQ stator
vd drJoc tdng hop bdi b0 nghich lrru PWM.
7- Quan he id -iq tdi uu
Do khdng cdn khAu tdch ddng (gidng nhu cho hQ ;lidu khidn vdcto
CHUONG 6
phudng trinh ndy chring ta cdn cdn th6m m6t phrrong trinh khdc, Th6ng
tin bd sung ndy c6 thd d4t rlrrgc thOng,eua mQt ti6u chudn tdi urr nhrr: gid
tri m6men/ ddng tdi da, mdmen/ ti th6ng tdi da, hiQu sudt tdi da, ...
Do d v{n tdc thdp hQ truydn dQng ldm viQc vdi chd d0 han ddng vd
ndu tr6n tdc tlQ ddng b0 or", hQ lim viQc vdi chd d0 tU th6ng suy gidm,
chring ta c6 thd sfi dung hai ti6u chudn ndy cho hQ truydn tlQng c14c tinh
cao. Ti6u chudn m6men/ ampe cu. c tlai alat dutoc bXng cdch sfi dung
phuong trinh (6.63) vd
i:=\W
a" =|nlar,
tld rrit ra drfoc
i'0,
-ro,-
(6.67)
+(Lo -
;Q'*;
u)-u^
-i'0,
L)i;l
t
(6.68)
-1.4
(6.6e)
=o
Cho trddng }aqp La = Lo , b6t ddu tir c6ng
thfc
(6.63) cho kdt qu6:
(6.70)
(ia, )lu=Ln = 0
Mdt khdc, cho gid tri mdmen/ tit th6ng cuq dai:
oi
= n/(opy
+Lai)z +(Lni)2
(6.71)
Trrong tu nhu trUdc, ta dat duoc mdi li6n hQ mdi gifra iar vDr iot
(o
"*
+
vdi
Loio*)2(zt o - Lq) - LdLqida(a pM + L6ia*) +(Ld
Lq)oi2 =
o
.: =f
I<hi Ld -
Lo
Cdc edng
(6.72)
(6.73)
- thfc (6.71) trd n6n:
, c6ng
Qru
/. \
(ia);o=r.o
=
hinh
-
thfc
-t
(6.68), (6.670), (6.71) vd, (6.72) drroc
rc.74)
trinh bdy tren
6.25..
Nhrrvfy, vdi m6i gi6
chudn
tdi rru, cdc gi6 tri
ngudng ddng
,j vir nggdng
tri
mdmen d4I M!,'theo mQt trong hai ti6u
duy nhdt cria tj Va i| e6.tl.rlgp;6,cung, cdp
tr} th6ng Oi khong ttrroc ph6p vugt qud.
orEu xutiN r6c oQ oQNo co odve aQ
M6men/tir th6ng
cq/c dai
C6c dudng elipse
trl thdng kh6ng ddi
b)
Hinh 6.25: Thd.nh phdn ia -io
a) Cho gid tr! i;
b) Cho gid tri Ai
tri gidi han cria tt th6ng li6n quan vdi v{n tdc o" (theo 6.74).
\n thC' mOmen M" bi gidi han tudng rlng vdi ddng stator vd tr] th6ng
Giri
(v4n tdc) (xem hinh 6.26a).
Gi6
i;
= fdLo(M.)
(6.75)
i;
= fqi,a(M.)
(6.76)
tri M. tdi cla phu thuQc v{n tdc (H.6.26b).
Iqo
fai
a)
o
Hinh 6.26: Quan hA 6i ttu
ia
-io
ud.
cdc ngxdng m6men,
til th6ng phtl
thu6c ud.n tdc
Vt dq 6.5. DQng cd PM-SM vdi V"o =tzOJrY, i"o = 20A, la =0,6p.u, diQn
:ip kh0ng tili eo =0,7p.u, lo=\,2p.u, nn=L|Y/gidy, p = L, G =0, t:ii
ddng 10A thay ddi t6'c d0 tldn gi6 tri tdc d0 co b6n z" theo ti€u chudn
m6men/ ampe cuc dai.
Gi:ri. Diiu ti6n chuy6n cdc giti tri trrong doi sang tuy6t
La = Ia
Lo = Io
v*-
,rr-
r,
o,!xr?0|F
=
2ox2nl5
=
TU
v"- =t,?:!-'of -= o,1o7z
H
'r,' - 2nl5*20 -
Qo,,
(6.5.2)
t"'
<Dpy c6 gi6
th6ng
(6.5.1)
o5aen
o,
Eo = eo.v"n =0,7 'L2oJ2 = 118,44
cloi
:,
?
v
(6.5.3)
tri:
(6.5.4)
--Eo -178'44
=1,257wb
2nl5
06
Sfi dung (6.69) vdi (6.5.4):
.,
,1.+r,..+
-c,
''(,
iai =
7,257
o,ob3g -o,lw7-Lo2
(6.5.5)
=o
(6.5.6)
-3,6454
rn,=rlffiilt,
(6.5.7)
=9,3r2A
vd mdmen
u, =Zol*
=
"*
+(Lo -
L)idfiq
(6.5.8)
9x1xf1,257+(0,0539-0,1077)(-3,645)]x9,312
2
L'
Tdc tlQ cqe dai mh mdmen c6 thd t4o dugc:
Qa; = Qpu + Laia =1,257 + 0,0539(-3,645) = 1,06
Q
a
q; = Loin = O,LO77 x9,3L2 = 1,00
",
=
Wb
r[o'o; a"a = f,.o6n 1Pd
--! %'
1,457
o"; -lzoJ'
20,3 Nm
(6'5'9)
Wb
= 1,457
(6.5.10)
wb
Nhu v4y, tldi vdi dien 6p dlnh mrlc (tliQn dp cqlc tl4i
tdc d0 co b6n:
ro- =
=
bQ
nghich hnr)
= 116,108 rad/s
11-6;1'08
v2. = -s- .-s
2np 2n.l =L8,454u1s =LLloul
ph
2- Didu hhidn u6etd d.bng gid.n ti€P
Srl dung c6c hAm tinh torin fitdc f6;,* Yd fqi,a ((6.75), (6-76) dd t4o
otEu xutEN r6c oQ oQNo
cdc
tin
hiQu ddng
d{t
t;
cd o6na a0
,fi,ii
dbng, ng6 ra khdu ndy s6 lA
(H.6.27).
Cdn s& dr;ng cAm bidn vi
27r
s6 drrgc tao ra vd. drra qua khAu higu chtnh
tin
hiQu di6u khidn b0 nghich lrru PWM.
trf r6to tld c6 drroc tin
hiQu
hdi tidp vi tri
vd vQn tdc.
KhAu hiQu chlnh
vi
.
tri G)r
KhAu hqn
KhAu hiQu chlnh
chd mOmen
ddng dgng AC
Hinh 6.27: Didu khidn udcto ddng gid,n tidp cho d6ng
3- Di6u hhidn abctd dbng ud dp gi6.n tidp
So tld duoc trinh bdy tr6n hinh 6.28.
co (PM
-
SM)
Hinh 6.28: Didu khidn gidn tidp udcto dp ud ddng cho dQng co DB
(PM-SM) udi khd.u hiQu chlnh ddng dsng DC
Phrrong
trinh
diQn dp stator dugc
st?
dung dd tdch tliQn dp:
vi =(r"+sL)ii-@,Lqi;
(dr---
(6.77)
(R
----Y
CHUONG 6
272
C6c khAu hi6u chinh dbng DC c6 thd thay thd thdnh phAn ildu ti6n
b6n vd phii cria cdc c6ng t:noc (6.77), (6.78) vd nhrr vQy chi c6 cric diQn
rip c6m rlng do chuydn ClQng ld trUc tidp. sau d6 tin hiQu cliQn :ip v;,v;
v;,v;,vj
bxng ph6p bidn ddi dq -+ abc vd b0
nghich lrru rtp PWM se tdng hop diQn rip pha y6u cAu theo kf thuQt cli6u
khidn vdng h6. d van t6c Lhdp, khdu hieu chinh ddng s6 tric dQng nhidu
hon. Nguoc lai, khau trich v{n tdc s6 chidm uu thd d v{n tdc cao.
s6 chuydn thdnh
tin hi6u
6.4.5 Di6u khidn trrrc tidp
(PM-SM)
trt th6ng vi m6men dong co d6ng
Cdu hinh tdng qurit crha hO thdng didu khidn tnlc tidp
m6men cho PM-SM drroc trinh bdy tr6n hinh 6'29'
tt
bQ
thong vd
M
Hinh 6.29: DTFC cho PM-SM
Bing d6ng c6t t6i uu dudc thidt lap dua tr6n nguyen lli v6 srr thay
iltii v6cto kh6ng gian ttr th61g stator lheo hud'ng cria v6cto kh6ng gian
di6n 6p sft dung:
o" =6"o
+i(D.r
(6.7e)
Nhu thd, dd teng m6men, ta phii tao v6cto tr) th6ng vudt trudc theo
hudng chuydn d6ng. Dd gia tdng ttr th6ng, g6c gifra v6cto V(i) vd v6cto
o- ph6i ldn hon 90o, v<icto cliQn rip phir hop s6 dttoc chon dua tr6n vi
tri cua v6cto o"o d trong g6c 60o ndo (xric dinh 0; ) (H'6.30). B6ng cl6ng
c6t c6 gi6
tri
gidng nhu trrrdng hop di6u khidn tnrc tidp
o
vd M
cho
otEu xnEx r6c oQ oQxa
co o6Na ee
273
-i.e
O=
-1
M=
-t
Hinh 6.30: Chgn udcto khing gian diQn dp cho g6c 1/6 tht nhdt
Khdu quan srit (nhfn dang) tir th6ng vd m6men c6 thd dugc thyc
hiQn trdn m6 hinh dbng - 6p, loc Kalman ho4c MRAS.
Khdu quan s:it vdng kin rip - dbng c6 thd duoc trinh bAy nhrr anu:
M6 hinh di6n :ip trong hQ truc toa d0 stator:
4'-"
-l
dt-=Vs-'lsls
(0,ruf
M6 hinh dbng diQn trong hG truc toa dQ r6to:
6on = Qii = Laia + Qpu + jLoio
;
ias
=ii
= ia +
jiq
Ddng trong h6 toa d6 r6to:
;s _;a
=r
trs = ls '€ '"er
(6,t I I
(0,rrl
TrI th6ng stator <Dl chuydn sang truc toa dQ stator:
6li = 61, .n""'
(0,t0t
Md hinh dbng bi dnh hrrdng bdi srr thay tldi th6ng sd (do b[o lrbn t0l
vd bdi sai sd vi tri, tuy nhi€n mO hinh hoat dQng tir vfn tdc bln5 0, iy
k€t hop hai m6 hinh :ip & ddng vdi khau bn PI tluoc thi€t kd sno cho n0
hinh ddng s6 chidm ul thd d vQn td'c thdp vd m6 hinh dp d vgrr tOo oro
(H.6.31). D6i tdn cho sg chuydn tidp phrJ thuQc vAo viQc chgn cdo h0 r{t
h; vit 'ci dga tr6n gid tri cdc crrc cho trrrdc o\ ve o4 cfia bQ quan rdtl
Hinh
Cac
giitr!
tt
th6ng ud tttOrtr'en
6.31: HA quan
stit
ki = -(toi +@2)
| ,, =![ 0)e
mAu cfia
cu1
)
(6.84)
(D1
vd to, ld o, ='-(3+10)rad/s
1
or, = -(3+10)lto1l
Ddp rlng vfln tdc thdp vh rndmen cho h0 t
trqrc tidp tU th6ng vd m6meu dd n6u vdi khAu
khidn theo chd atQ trtlgt (sliding mode) vdi crig
u khidn
d0 didu
4'1mH'
Lo=8,2mH, Opy =0,2Wb, 6 =0,6,C), J =0,?O5h€4.t2 'P'= 4'f"=l'0KHz'
Va=200V, M-u*--.12Nm drroc trinh bdy tr€n hinh 6'32' Ddi tr6
(hysteresis band') cria tt thdng vd mdmen ld 0,5"/a vit T-c/c'
2r'n
Iradls]
60
0;0s 0,1 0,15
0,2
Einh 6.32: Quci dQ uQn tdc thdp ud' rtt'6n't'ut'
c6 thd kdt luan vd xna ndng di6u khidn nhauh m6rnen. VaD t'6'q.
kh6ns c6 vot ld nhd srl dung khdu hiQu chinh vsu toc theo chd dQ trtfQt,
oEu xnEN r6c o0 o2vo co o6tuo a0
276
6.b HC TRUyEN 00Nc oOuc cd sduc s0
(RSM
-
rUrn0
BELUCTANCE SVNCHRoN0US M0T0R)
DQng co tldng bQ til tr& RSM tl{c tnrng lA kh6ng hiQn diQn cdc logi
dbng trong cdu hinh r6to. Vdi cdc cdu hinh vdi tl s6 LalLo cao, hQ sd
c6ng sudt vd hiQu sudt le tudng ducmg ho{c cao hon mQt chrit so vdi
DCKDB. Do kh0ng c6 dbng r6to, d{c biQt khi mdy phdt xung (encoder)
drroc sr? dqng dd h6i tidp vi tri rdto, hQ truy6n dQng RSM s6 don gi6n
hon nhidu so vdi hQ truydn dQng DCKDB.
Tdn hao l6i cfia m4ch r6to dudc xem ld kh6ng c6 cho trudng hgp l9
tudng (tr€n thrrc td c6 sg tdn hao do cdc thdnh phdn s6ng hdi cria tr}
th6ng). Do d6 dQng co RSM c6 thd lim viQc an toin d tdc dQ thdp vA
m6men ldn. Th0ng thudng dQng co RSM c6 thd dugc rfng dung cho pham
vi cdng sudt til 100W ddn lMW vd tdc dQ roto t6'i da khoang 50 - 60m/s.
Hinh 6.33: Cdu tqo crta r6to ilQng co til trd RSM
a) Voi ctic chd.n til thing nhidu
7- NguyOn
I6p;
b)
ALA;
c) Truydn thdng
$ ili6u hhidn v6etd eho RSM
DQng co RSM c6 thd tltrgc xem nhu mQt hQ phi tuydn vdi hai ng6
vdo; ttt th6ng stator @' vA mdmen M.
j(Loq -Qp*o)
6:
= L6ia +
fo
=lrr*o+(to-t )iofto
.
(6.85)
v6i PM - nam ch6m vinh crfu drrgc th€.m vAo tnrc q. Til th6ng do PM siah
ra ngugc chi6u vi ldn hon gid tri Loio: rbpy,o2Loio. \n thd io kh0ng
tlrrgc d6o ddu khi cdn mQt gid tri m6men til trO duong trong trudng hgp
srl dgng nam ch6m (PM). Khi cdh chuydn m6men trl duong sang 6m, cln
CHUANG 6
276
Nguoc lai, khi kh6ng s& dung nam chAm th6m vdo trgc g, nghia Ii
Qr,no =-0, th6ng thudng dd ttAo ddu mdmen, ctf. c tfnh clfia io s6 thay ddi.
Do La>Lo,g1u! d0 ddng ia s6 ldn hon so vdi iovDr vi thd ddp ring
m6men sE nhanh hon cho trudng hgp didu khidn ddng io.
d
aay kh6ng
c6 dbng r0to, khau tdch ddng rdto kh6ng cdn cdn nr1a. Thay vdo d6 lA
vdn tld tim mdi tudng quan cfia cdc thdnh phAn ia, io vdi mdmen drla tren
cdc ti6u chudn t6'i ru d4c tinh dd drroc tld cap ddn 6 muc 6'4.4.1. Ti6u
chudn thr,tc td drroc dilng c6 thd ld:
tri t6'i da m6men/ ampe d v{n tdc thdp.
- Gi6 tri tdi da til th6ng/ m6men 6 van t6'c cao.
- Gid
- HQ sd cOng sudt crtc dai hoic hiQu sudt'
Dd <lat tiOu chudn giri tri m6men/ ampe cu.c tl4i (vdi Qpuq =O).
(6.86)
ior=ior=i"lJ2
u,
=f,n@a - L)iT;t
Do i4<0,5i^.Jt (i"- tri hiQu dung ddng tlinh mrlc pha) nhhm
trdnh b6o hda til cao, khoing mQt nfia m6men dinh mrl'c tlrroc ding khi
srl dung ti6u chudn ndy.
Ti6u chudn he sd c6ng sudt cuc
tsst =
'
cudi ctng i?i
ti*
dudc
d4i (t"
= O) drra
L4,t: | 2:Lro,ioo,t z
(Ld
- L)idiq
tr6n dinh nghia:
.
(6S7)
(khi dLf:Q'\=o),
"lT)
fr.) =E
['o.[,-, \Lo
Me,
,
\
(cos{P1,1661
Cho ti6u chudn gid
=|n@o=
(6.88)
L).izd
L-LolLd
l*
Ln I h
tri cuc dai mOmen/til thdng:
(6.8e)
(6.e0)
otEu xurEN r6c oQ oQr'to co o6Na e0
ia*
Ld'
iqo-Lo
.
Od*=Oqo=@rl..12
277
(6.e1)
nhu v{y, vdi ia* = io.
ho4c
a* =|nLa - L)fit?;
rc.e2)
M*=|p[o-"r)#
(6.93)
M6men cr,rc d4i c6 thd. d4t dugc vdi ti6u chudn gid. tri cuc dai
mdmen/tir th6ng, tuy nhi6n, cho hQ sd c6ng sudt thdp nhdt (nh6 hon mQt
it so vdi 0,707). Tdc t10 ddng bQ cd bAn ol" , dugc xdc tlinh cho trudng hop
d4t m6men crtc dai:
(6.e4)
t{ cho cdc h6 truydn dQng servo kh6ng ldm viQc 6 ving c6ng
kh6ng
tldi (suy gi6m tir th6ng) vi c6 ddp r1'ng v{n tdc cao, ti6u chudn
sudt
hQ sd cOng sudt crtc dai cd, thd duoc srl dung d xdc lfp. D6i ry6i cdc qud dQ
nhanh, ti6u chudn cqc dai m6men/til th6ng c6 thd duoc chgn. Trong
tnrdng hgp niy, b0 nghich lur PWM dtroc tlfnh mrl'c ddng rdt qao dd c6
thd th6a y6u cdu ddp rltrg nhanh tdc d0 khi quri d0.
QuI ttao cric thdnh phdn ddng ia-io vd. til thdng @a-Oc cho ba
Thrr. c
chidn luoc tli6u khidn tdi rnr chinh dtrgc trinh bdy trOn hinh 6.34.
CHUONG 6
c6c cdng trinh nghien crhr vd ldnh vgc ndy cho mQt sd kdt luan nhu sau:
- Anh trrrang cfia b6o hba tU (chri ydu ciua La) rdt thdp khi tlidu
khidn theo hQ sd c6ng sudt cuc dai. Ngrroc lai, khi didu khidn theo
mfimen/trl th6ng cUc dai, inh hrrdng cfia bdo hba tir l6n tl4c tinh ld ddng
kd. Cho c6c gi6 trf m6men nh6 vi drrdi v4n tdc ddng bQ co bdn, di6u
khidn c6 thd thrr. c hiQn theo quf dao ddng d-q OA^B*. Khi tdc dQ tren
tdc ilo cd b6n, vdi didu khidn c6ng sudt kh6ng ddi, tlidu khidn theo qui
d,ao
OB^C^. Vi v4Y g6c tao bli id
y --
i,
a.rctg:
vi
,
do:
(6.e5)
lq
Cdn thay ddi theo m6men (vd v4n tdc):
- Khi lhm viQc vdi g6c tao bdi tu th6ng Q4,Qo, c:ic didu kiQn trlong
tu nhu tr6n cfing c6 thd gap. (H.6.34b). Th6ng thddng, cho pham vi rQng
(<o-"* /ol" > 2) cria ving c6ng sudt kh6ng ddi, y6u cdu ddt th6m nam
chAm vinh c&u vdo truc q. Cho ving tdc d0 thdp, thrrdng sfi dung phrrong
ph6p tlidu khidn v6cto ddng, vdi vQn tdc trdn t6'c d0 cd bin phuong ph6p
tli6u khidn v6cto dp drroc sfi d,lng.
_ Giai ph6p didu khidn cho ph4m vi tdc d0 rong thrldng dlng vd
phdi hgp tlidu khidn v6cto ddng ph6'i hop vdi phAn tdch rip trong hQ trgc
iqa dEr J-q hoac dinh hrrdng theo v6cto til th6ng stator. Cdc mgc kd tidp
trioh bdy phrrong phdp didu khidn v6cto th6ng qua hQ thdng di6u
"i
khidn V6cto ddng d-q vdi dbng ia kh6ng ddi cho tdc d0 thdp hon ho{c
blng tdc alo tl6ng bQ co b6n 0)" va ia phq thuQc v{n tdc khi tdc dQ tr6n
tdc do,co bfln. Phrrong ph6p {li6u khidn trrlc tidp til th6ng vd mornen
cfrng drrgc gi6i thiQu'
2- Di6u hhi6n vbeto d'dng gid'n tidp
so d6 di6u khidn drrgc trinh bdv tr6n hinh 6.35.
HQ thdng cho ph6p tlidu khidn v4n tdc ho4c vi tri. Thdnh phan tldng
tir h6a yeu cdu ij c6 gt|tri khdng ddi khi van tdc nh6 hon ho4c bxng tdc d0
cd ben o)" vh giam tl lQ nghich vdi vfn tdc khi tdc cto I6n hctn rrr".
Kh6u hiQu chlnh t6'c ttO duoc tli6u khidn theo chd tlQ trrrot' Ng6 ra
cria kh6u hiQu chinh t4o ra tin hiQu dbng tlat tudng ring m6men ii vd
quy lu{t tlidu khidn tlon giAn nhdt c6 dang:
ii=+iox khi Sr>co7, ho{c lS.l < tol, S'<0)
(6'96)''
i=-ioxkhi s,D(-o1 hodc (lsrl< tol, S'>0)
vdi co,, le dai fi6 (hysteresis barid.) cfra khdu hiQu chlnh vd s, ld hdm sd
otEu xutEN r6c oQ oQua
co o6na aQ
s, =Ko.(<ol
zTll
-.J-K^#
(6,0?)
v{n tdc
hoac vi tri didu khidn
theo chrd d0 truot
KhAu hi6u chlnh
do vi tri
Hinh
6.35:
Di6u hhidn udcto dQng co d6ng b6 td tr& RSM
Ngodi viQc thidt lap didu
kien dd dat dudng thEng S, = 0
(trong m{t ph&ng kh6ng gian
trang thrii) chring ta cdn bidt
Ko^ vd Kd,. Dd lim drroc tlidu
d6, ta chdp nhfn ld in thay tldi
tuydn tinh theo thdi gian vd vfn
tdc cdn dat tlrrgc ol s6 th6a sau
khi S.o ddo ddu it nhdt 1 ldn
(H.6.36).
Hinh 6.36: Cdc qud dQ l! hnlny
(ia= const; ir: thay ddi tuyln llnh)
ta
Ti sd K. =':;d'- cdn drroc xdc dinh trrrdc ti6n.
As,
NOu d
thdi tlidm f = O,
ari
-or"(r,) =
S<o
=
0, khi khOng rai, (6.97) trd thAnh:
*,#= K..}.ruQ)
(tl,ol{)
bidn thi6n tuy6'n tinh, mdmen M c[ng bidn thi6n trldnt tU trlrrl
vdy (ia= const) vd til /o ddn f, +tl (H.6.36), ta c6:
ndu
do
+=]*<,"',1,,
(f ,llll)
CHUANG 6
280
Tich phdn hai vd cria (6.99) cho kdt qui:
i,ri
(6.100)
- ro,(t,) = 2J'
|tr. MG")
So srinh (6.100) vdi (6.98),
ta duoc:
Kr=\
(6.101)
2
C6
thd sfi dung ph6p xdp xi l,
K'=
L
={, .ut."
!3-
(6.102)
4r,
Bing crich gidi han sai sd d trang thrii xric ldp ta c6 thd tim drroc
quan hQ thf hai dd tinh todn Koto vd K6, vd nhrl v4y khAu hiQu chinh
tntot hodn todn dtroc xric dinh.
Trrong tu cho tnrdng hop giam tdc mQt crich tuydn tinh hic hdm, mQt
b0 hieu chinh vi tri theo chd tlQ trrrot cung c6 thd duoc thidt kd' Cdc
chd d0
th6ng sd cria n6 ld Koe vd Kar.
3- Di6u hhidn tr(e tidp tit thhng ud' rndmen d'Ong eo d'6ne b0 RSM
cdu hinh co b6I} ctia hQ thdng ilidu khidn duoc trinh bdy tr6n hinh 6.37.
M(1,
-1)
fc
os
(1.,...6)
v
t
1- Vdi c6m biSn v! tri
2- HC khOng cAm bi6n
Hinh 6.37: Ei6u kh.idn tnlc tidp m6men ud, tit th6ng d6ng co d6ng b6 tt tr&
c:ic b0 quan s6t tt th6ng vd m6men c6 tinh chdt quan trcng cao
trong h0 thdng cli6u khidn. Cho trrrdng hgp didu khidn kh6ng ding cim
bidn, mQt bQ quan srlt vQn tdc s6 duoc sfi dung. BAng quy h,4t d6ng cdt
tdi rru drroc phrit tridn cho hQ truydn along dQng cd PM-SM cung c6 gi6
tri trrong ttf ch.o hc TD RSM, chi klrric d khdu quan sdt tt th6ng vd
mdmen: til th6ng PM truc d c6 giri tri 0 (H.6.31) vd c6 tt d trr] bdt d trgc
Hfr
I
TAI LIEU TI:IAM KIIAO
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
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