ISSN XXXX XXXX © 2016 IJESC
Research Article
Volume 6 Issue No. 8
Design and Implementation of Three Level Isolated Single Stage
Power Factor Corrected Converter
Supriya Chincholli1 , Prof.Smt.F.N.Kudchi2
PG student1 , Professor2
Depart ment of Electrical and Electronics
BLDEA’s Engineering College, Bijapur, India
Abst ra ct :
For low-cost isolated ac or dc power converters adopting high -voltage dc-lin k, research efforts focus on single-stage multilevel
topologies. This paper proposes Single Stage Power Factor Corrected Three Level Converter for high dc-lin k voltage lo w-power
applications, achieved through an effective integration of ac or dc and dc or dc stages, where all of the switches are shared between
two operations. With the proposed converter and switching scheme, input current shaping and outp ut voltage regulation can be
achieved simultaneously without introducing additional switches or switching actions. In addition, the middle two switches ar e
turned on under zero current in discontinuous conduction mode operation, and the upper and bottom switches are turned on under
zero voltage. Due to the flexib le dc-link voltage structure, high power factor can be achieved at high line voltage.
Keywords: Mat lab simu lin k, converters.
I INTRODUCTION
For improvement of grid quality and full capacity
utilizat ion in transmission lines, an Ac or Dc power converter
is used. These converters operate with high power factor (PF)
and low Total Harmonic Distortion (THD).By achiev ing high
PF with high efficiency, inductive and capacitive filters
followed by a d iode bridge are used in Passive PF correction
(PFC) circuits. In a circuit, low line frequency filters are
needed but they are heavy. In high frequency operation the
circuit size must be reduced, two stage of high frequency PFC
converter proposed [1]-[4]. W ith Si semiconductor devices,
switching frequency operates fro m 10 to several 100 kH z, in
front end of Ac or Dc PFC converter. W ith wide-band gap
devices, switching frequency operates from several 100 kHz to
10 MHz’s. Next stage is Dc/ Dc converter; this gives output
voltage regulation as well as galvanic isolation. In t wo stages
controllers are independent. In a light load condition, by
reducing efficiency of the converter, constant switching losses
are occurs those are parasitic capacitance losses. In this
method more number of costly and big size of co mponents are
used. For min imu m cost, number of switches is reduced in
Single Stage Ac or Dc converters [5]-[10]. Init ially by
dividing control scheme and few switches in a c ircuit, Dc/Dc
stage and front end of PFC stages were integrating and
operations are performed in Single Stage. An inductor or
capacitor, unit of energy storage are present in center of two
stages, acts as a power buffer and gives good time. This circuit
exactly operates in Discontinuous Conduction Mode (DCM)
for simp le PF control. For input current shaping and output
voltage regulation, Switches are suffered fro m more current or
voltage stresses and its power level is not more than 200W. In
many researches, more focus on average to maximu m power
applications, in Single Stage Fu ll Bridge converter (SSFB). To
reach high power factor, current shaping inductor is spread out
by current fed SSFB converters and it is connected to input of
Diode Bridge. Dc bus voltage is beyond mark because in
Transformer, Dc bus capacitors are present in the primary
side. Due to the high amplitude in output voltage, the
frequency is doubled and its operation also within the limit. In
a Dc bus, high value capacitor is present on primary side. In
International Journal of Engineering Science and Computing, August 2016
light Load situation Dc bus voltage is high, output regulation
and input current shaping are done in a single controller. In
Discontinuous Conduction Mode, above mentioned
converter’s output current ripple is very high and operation
becomes transient. Switches are unprotected due to high
voltage pressures, in double Level SSFB converters. But in
mu ltilevel converters, the voltage pressures across the
Switches are highly reduced. Range of the Dc lin k voltage is
in between 400V to 800V. In a Discontinuous Conduction
Mode, input current is adjusted with constant duty cycle
because to decouple the dc bus voltage and output voltage
controllers. Bottom Switches are simultaneously transfers
energy from Dc bus to output and shapes the input current. In
the center of separate Dc bus capacitor two Diodes are
connected because to protect input current.
II LITERATURE S URVEY
“A new regulation methodol ogy for a buck -support info
AC/ DC converter”
A novel regulat ion methodology for a force element
revised (PFC), d isengaged AC/DC converter got fro m the
reconciliation of a non isolated, two switch buck-support
AC/DC converter with a segregated double dynamic scaffold
DC/DC converter (2SBBDA B). This methodology, termed
spasmodic driving/trailing edge (DLTE) tweak, serves to
augment the obligation cycle of the information switch wh ile
keeping the current in the buck-support inductor broken. Thus,
the peak co mponents of the streams in the exchanging gadgets
are minimized, the info switch is turned on at zero cur rent and
the zero-voltage exchanging scopes of the scaffold switches
are unaffected by the coordination. A traditional detached,
PFC A C/DC converter ordinarily co mprises of a help
converter fell with a forward converter. The evaluations
required of the force exchanging gadgets of the 2SBBDAB
utilizing the DLTE tweak methodology are like those required
of the tradit ional outline for wide line voltage operation. In
any case, the 2SBBDA B converter has higher line voltage
surge resistance than that of the routine configuration and,
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dissimilar to the customary outline, it has characteristic inrush
current constraining.
B.
MODES OF OPERATION
Mode I
“A Single-Switch AC/DC Fl y back Converter Using a
CCM/DCM Quasi-Acti ve Power Factor Correcti on FrontEnd”
The significant issues that exist in the single-stage air
conditioning/dc converters with force element remedy (PFC)
and present a novel converter in view of a semi dynamic PFC
plan. Two extra windings twisted in the transformer of a
traditional dc/dc flyback converter are utilized to drive and
accomplish ceaseless current mode operation of an info
inductor. Furthermo re, coordinate vitality exchange ways are
given through the extra windings to enhance the change
proficiency and to lessen the dc transport capacitor voltage
underneath 450 V for widespread line applicat ions. The
proposed converter can be effectively intended to consent to
IEC 61000-3-2 Class D necessity and to accomplish quick
yield voltage d irection. By leg itimately tuning the converter
parameters, a great tradeoff between effectiveness, dc
transport capacitor voltage anxiety, and symphonious
substance can be accomplished.
This mode is valid for t 0 to t 1. Switch S1 and Switch S2 are
ON and diode D8 conducts at the auxiliary side of
Transformer. Applying – Vdc/2 to primary side of the
Transformer, the capacitor Cdc1 d ischarges to the load and
VL0=Vdc/ 2N-V0.
Mode II
III B LOCK DIAGRAM AND OPERATION
The proposed converter is essentially an integrated version of
a boost PFC circuit and three-level isolated dc–dc converter.
Basically, a d iode bridge and an inductor are added to the
three level isolated dc–dc converter topology. The proposed
converter exhibits high PF with less number of
switches/diodes. With the proposed converter and switching
scheme, input current shaping and output voltage regulation
can be achieved simu ltaneously without introducing additional
switches or switching actions.
This mode is valid for t1 to t 2.Switch S1 is OFF and Switch
S2 is remains ON and diode D5 conducts. Across the Primary
side of Transformer zero voltage is applied and current
freewheels. Output voltage of inductor is equivalent to – V0
and output current of inductor is reduces straightly.
A.
Mode III
BLOCK DIAGRAM
Fig.3.1 three level isolated single stage PFC converter.
This mode valid for t 2 to t3, Switch S2 and Switch S3 both are
ON, that t ime primary side of current is continuous to
freewheel and zero voltage is on primary side. Under output
voltage, output current of inductor is continuously decreases.
That time Vin connected crosswise over Lb and energy is
stored in the inductor.
Mode IV
Fig.3.2. S witchi ng operation
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This mode valid for t 8 to t10, Switch S3 is OFF; both Switch
S1 and Switch S2 are ON. Its operation is same as mode 4. In
inductor energy is stored and that energy transferred to Dc bus
capacitor. In this situation output current of inductor flows in
between D7 and D8.
IV S IMULINK MODEL
Discrete,
Ts = 1e-07 s.
ID5
<Diode current>
powergui
Goto4
[S1]
+
+
S
D
g
m
g
D
m
S
Scope3
ID6
From7
Co
Ro
Goto3
Pulse
Generator3
TF
S3
k
m
k
From2
m
ID5
From6
[S4]
+
3
[S3]
D4
m
a
a
a
Goto2
Lo
1
I
D2
Pulse
Generator2
[S3]
+
2
+
S
a
+i
-
k
D7
+
S2
Vac
Goto1
m
a
From1
Pulse
Generator1
Goto6
[S2]
D3
a
D1
From5
ID7
<Diode current>
a
k
Lb
k
k
m
m
Goto8
ID7
From4
[S2]
D5
m
+
[Iin]
[S1]
Goto
ID8
Cdc1
m
S1
Mode V
Pulse
Generator
+
g
From
D
This mode valid for t 3 to t5, Switch S2 is OFF and Switch S4
and S3 are ON. Stored energy in the inductor, transfers the
energy to the Dc link capacitor. In between Vin - Vdc
inductor current decreases straightly, that time Vdc/2 is
applied to the primary side of the Transformer. In leakage
inductance, current is transferred to Cdc2 in this situation
output current flows fro m D8 to D7. At t=t 5 stored energy in
Lb is transferred to the dc link and at t=t6 current flows fro m
D8 to D7 is fin ished.
m
a
+
g
<Diode current>
ID8
Goto7
Cdc2
m
S4
Scope
S
From3
k
k
D6
D
[S4]
D8
1
Vtr
<Diode current>
Vo1
Product
This mode is valid for t 5 to t6.Switch S3 and Switch S4 are
ON and diode D7 conducts. That time Cdc2 is discharges and
Vdc/ 2 is used in primary side of the Transformer. In output
inductor voltage is VL0=Vdc/2N-V0.in a discontinuous
conduction mode input current always at zero.
Io1
Itr
Vin
1
Po
Vin Iin
[Iin]
Io
Iin
Io2
1
1
Vo
1
1
ID6
Goto5
1
1
IC1
ILb
V Mag_V_I
P_Q
I
1
pf
Discrete
Active & Reactive
Power
-1
Gain
Scope1
1
IC2
-1
Scope2
Gain1
VLo
pf
Fig 4.1: simulink model
Mode VI
V S IMULATION RES ULTS
This mode is valid for t 6 to t7, Switch S4 is OFF and Switch
S3 is ON. Both diode D6 and D7 are conducts and D6 allows
leakage current to freewheel. Under – V0 output current is
decreases.
Fig.5.1 s witching operati on
Mode VII
This mode is valid for t 7 to t 8. Switch S2 and Switch S3 are
ON. Input side of energy is stored in inductor and its operation
is same as mode 3. Excluding that in mode 3 primary side
current is opposite.
Mode VIII
Fig.5.2 Transformers voltage and current
Fig.5.3 output inductor vol tage.
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frequency of input current is double of the Switching
frequency. The design and control o f the circuit is solved by
regulating output voltage and shaping input current. By
changing the Dc lin k voltage fro m 400V-800V, line voltage
will be within 265V and Power Factor will increase fro m 0.88
to 0.99.
VII REFERENCES
Fig.5.4 Output inductor current
[1] J. R. Morrison and M. G. Egan, “A new modulat ion
strategy for a buck boost input AC/DC converter,” IEEE
Trans. Power Electron., vol. 16, no. 1, pp. 34–45, Jan.
2001.
[2] H.Wang, S. Dusmez, andA.Khaligh, “Design and analysis
of a full bridge LLC based PEV charger optimized for
wide battery voltage range,” IEEE Trans. Veh. Technol.,
vol. 63, no. 4, pp. 1603–1613, May 2014.
Fig.5.5 output Capacitor current.
[3] J. Y. Lee and H. J. Chae, “6.6-kW on-board charger design
using DCM PFC converter with harmonic modulat ion
technique and two-stage DC/DC converter,” IEEE Trans.
Ind. Electron., vol. 61, no. 3, pp. 1243– 1252, Mar. 2014.
[4] H. J. Chiu, Y. K. Lo, H. C. Lee, S. J. Cheng, Y. C. Yan, C.
Y. Lin, T. H.Wang, and S. C. Mou, “A single-stage softswitching fly back converter for power-factor-correction
applications,” IEEE Trans. Ind.Electron.,vol.57, no. 6, pp.
2187–2190, Jun. 2011.
[5] H. Ma, Y. Ji, and Y. Xu, “Design and analysis of singlestage power factor correction converter with a feedback
winding,” IEEE Trans. Power Electron., vol. 25, no. 6, pp.
1460–1470, Jun. 2010.
Fig.5.6 Diodes side current.
Fig.5.7 Power factor
V FUTUR E SCOPE
The proposed converter is utilized for the
straightforward circu it structure development for the powerful
thickness application. The proposed idea is further can be
utilized as the consistent dc voltage is required, whether it can
be a lattice, dissemination or t ransmission framework. Since
the extent of the converter got lessened the proposed converter
goes about as the all the more pro ficiently and less warmth
misfortunes where space of the execution required less.
VI CONCLUS ION
[6] S. Dusmez and A. Khaligh, “A charge-nonlinear-carriercontrolled reduced-part single-stage integrated power
electronics interface for auto motive applications,” IEEE
Trans. Veh. Technol., vol. 63, no. 3, pp. 1091– 1103, Mar.
2014.
[7] Y.W. Cho, J.-M. Kwon, and B.-H. Kwon, “Single powerconversion AC–DC converter with high power factor and
high efficiency,” IEEE Trans. Power Electron, vol. 29, no.
9, pp. 4797–4806, Mar. 2014.
[8] L. Rosseto and S. Buso, “Digitally-controlled single-phase
single-stage ac/dc PWM converter,” IEEE Trans. Power
Electron., vol. 18, no. 1, pp.326–333, Jan. 2003.
[9] H. Athab and D. Lu, “A single-switch ac/dc fly back
converter using a CCM/DCM quasi-active power factor
correction front-end,” IEEE Trans. Ind. Electron., vol. 59,
no. 3, pp. 1517–1526, Mar. 2012.
[10] D. D. C. Lu,H.H.C. Iu, and V. Pjevalica, “A single-stage
AC/DC converter with high power factor, regulated bus
voltage, and output voltage,” IEEE Trans. Po wer
Electron., vol. 23, no. 1, pp. 218– 228, Jan. 2008.
In low power applications we can use this three level
Single Stage PFC converter. In this paper shows in a constant
duty ratio how high Power Factor will be achieved by using
minimu m nu mber of Diodes or Switches. The switching
operation is modified and consistant with Single Stage
operation by adding Diode Bridge and inductor to Three Level
Dc to Dc converter. By using lower PFC inductor, ripple
International Journal of Engineering Science and Computing, August 2016
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