ISSN 2277-2685
IJESR/August 2015/ Vol-5/Issue-8/1043-1050
B. Vanitha et.al.,/ International Journal of Engineering & Science Research
MULTIOUTPUT FLYBACK CONVERTER FOR PMSG BASE WIND ENERGY
CONVERSION SYSTEM -SOFT SWITCHING IMPLEMETATION
B.Vanitha*1, Siddani Ramesh2
1
M.Tech, Malla Reddy Engineering College (Autonomous), Hyderabad, Telangana, India.
2
Prof, Dept. of EEE, Malla Reddy Engineering College (Autonomous), Hyderabad, Telangana, India.
ABSTRACT
This paper exhibits another multioutput converter for PMSG wind energy transformation framework (WCS). It
comprises of a half-connect inverter in essential side and a flyback rectifier that is incorporated with an assistant
buck converter in auxiliary. The essential switches control the principle yield voltage and the auxiliary
synchronous switches control the assistant yield voltage. The primary focal points of the proposed converter are
that the transformer size can be lessened because of the lower polarizing counterbalance present, all the switches
including synchronous ones can accomplish the zero-voltage exchanging, and it has no cross regulation issues.
The operational rule, examination, and outline contemplations of the proposed converter are exhibited in this
paper. A reenactment and gear examination of the proposed topology has been done by using
MATLAB/SIMULINK.
Keywords: Buck, flyback, multioutput, synchronous switch, zero-voltage switching (ZVS), Wind energy
conversion system.
1. INTRODUCTION
The idea of multi yield terminals can be connected to the renewable vitality framework like wind vitality
transformation frameworks which is taking into account changeless magnet synchronous generator. This
discovers significance in small scale network levels, remote town utility supply needs and so forth.
2. PMSG-BASED WIND POWER CONVERSION SYSTEM
2.1. Aerodynamic and Mechanical systems
The operational execution of wind turbine can be demonstrated through a numerical connection between the
wind speed Vw and mechanical force extricated as takes after:
(1)
Proposed system block diagram
*Corresponding Author
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B. Vanitha et.al.,/ International Journal of Engineering & Science Research
Fig. 1: The schematic representation of a PMSG-based WECS unit
Fig. 2: Proposed Converter
where Pwt is the separated force from the wind, ρ is the air thickness, r is the razor sharp edge range, and Cp is
the force coefficient which is an element of both tip speed proportion, λ and sharpened steel pitch point, β .
Numerical estimates have been produced to compute Cp as takes after:
(2)
with
(3)
On the off chance that the air thickness and sharpened steel cleared range are constant, Pwt relies on upon the tip
speed proportion and the turbine speed. The greatest yield force of the wind turbine is ascertained at the most
extreme force change coefficient Cp max and the ideal tip speed proportion λopt :
(4)
where
, and ωt is the precise pace of the wind turbine sharpened steel. The greatest
force is gotten by directing the turbine speed with regarded to the wind speed such that the most extreme force
point following (MPPT) can be accomplished. The MPPT gives the reference power, Pref , for the network side
converter talked about from now on.
As of late, direct-determined PMSG has increased extensive enthusiasm because of its points of interest
including no apparatus upkeep, unwavering quality and proficient vitality creation. In this way, investigation of
element qualities of the determined train is turning into a worry of most extreme significance. In this paper, the
determined train is spoken to by one-mass model:
(5)
where J is the consolidated idleness of turbine and generator, Twt is the streamlined torque delivered by the
turbine, and Tg is the electrical torque.
2.2 PMSG Representation
The calculations connected with the PMSG displaying in abc reference edge are confounded and long.
Normally, the dq0 or Park change is connected in the PMSG displaying. The electromagnetic comparisons of
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B. Vanitha et.al.,/ International Journal of Engineering & Science Research
PMSG are depicted taking into account the dq0 reference outline in which the q hub turns synchronously with
the magnet flux ψ f as takes after:
(6)
(7)
where Lsd , Lsq and Rs are the generator inductances and resistance, individually. ωg is the rakish rate of the generator.
3. OPERATIONAL PRINCIPLE OF PROPOSED CONVERTER
This multifunction is the outcome from the door sign controls of these switches, which will be dissected in the
accompanying area. Fig. 2 demonstrates the circuit design of the proposed flyback converter with two yields. It
comprises of a half-connect inverter from Conventional half-connect flyback converter with helper buck
converter and got auxiliary rectifier from Integration of the optional switches.
Fig. 3 demonstrates the key working waveforms of the proposed converter in the relentless state. Every
exchanging period is subdivided into six modes and their operational modes are demonstrated in Fig. 4.
The principle switch QM is worked in an obligation proportion of D, and the helper switch QA is worked
corresponding to the primary switch QM. The optional switch QS2 is turned ON at the same time with QA, and
QS1 is turned ON after QS2 is killed The principle and assistant yield can be managed by controlling the
obligation proportions D and DS, separately, where D is the obligation proportion of the primary switch QM ,
and DS is the obligation proportion of the cover interim of QM and QS2 .
So as to show the consistent state operation, a few suppositions are made as takes after:
1) All parasitic parts aside from those predetermined in Fig. 2 is disregarded;
2) The parasitic capacitances COSS1 and COSS2 of the essential switches are the same capacitance of C OSS ;
Fig. 3: Key waveforms of the proposed converter
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3) The yield voltages VO1 and VO2 , and blocking capacitor voltage VCB are consistent amid an exchanging
cycle;
4) the transformer turns proportion n = NP/NS .
Mode 1 [t0–t1]: Mode 1 starts when the spillage current ilkg (t) comes to iLm(t) + iLO1 (t)/n. In the essential
side, VS − VCB is connected to the transformer, so the charging current iLm(t) is straightly expanded. In the
auxiliary side, the yield inductor current iLO1 (t) courses through the switch QS2 and the assistant yield is in
fueling mode. ilkg (t), iLm(t), and iLO1 (t) can be communicated as takes after:
ilkg (t) = iLm(t) + iLO1 (t)/n,
VS − VCB
iLm(t) =
Lm + Llkg
(8)
(t − t0) + iLm(t0 ),
(9)
(10)
(a)
(b)
(c)
(d)
Fig. 4: Operational modes of the proposed converter (a) Mode 1 (b)Mode 2 (c)Mode 3 (d)Mode 4 (e)Mode
5 (f) Mode 6 (Gray line means non conducting device.)
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Mode 2 [t1–t2]: In this mode, QS2 is killed. iLO1 (t) moves through QS1, so the helper yield goes into the
freewheeling mode. iLO1 (t) is not reflected to the essential side. ilkg (t), iLm(t), and iLO1 (t) can be
communicated as takes after:
(11)
(12)
Mode 3 [t2–t3]: Mode 3 starts when the fundamental switch QM is killed. It expect that ilkg (t) is consistent
amid this mode. Accordingly, COSS1 and COSS2 are directly charged and released by ilkg (t), individually. In
the optional side, the voltage of QS2 is likewise diminished. At the point when the essential voltage comes to
−VCB, the ZVS of the switches QA and QS2 can be accomplished. ilkg (t), iLm(t), and iLO1 (t) can be
communicated as takes after:
ilkg (t) = iLm(t) = iLm(t2 ),
(13)
.
(14)
Mode 4 [t3–t4 ]: Mode 4 starts when QA and QS2 are turned ON with ZVS. The force is exchanged from the
essential side to the principle yield VO2 . The voltage over the spillage inductance is the distinction between the
voltage reflected from the auxiliary side, nVO2 and the blocking capacitor voltage, VCB.
The optional transformer current is n(iLm(t) − ilkg (t)) and the assistant yield is still in freewheeling mode. In
this mode, the present moving through QS1 is the aggregate of iLO1 (t) and the switch QS2 current iS2 (t). ilkg
(t), iLm(t), iLO1 (t), and the optional switch current iS2 (t) and iS1 (t) can be communicated as takes after:
(15)
(16)
(17)
iS2 (t) = n (iLm(t) − ilkg (t)) ,
(18)
iS1 (t) = iS2 (t) + iLO1 (t).
(19)
Mode 5 [t4–t5 ]: In this mode, QA is killed. COSS1 and COSS2 are reverberated with Llkg , and released and
charged by ilkg (t), individually. In optional side, QS2 is still on state. ilkg (t), iLm(t), and iLO1 (t) can be
communicated as takes after:
(13)
(14)
(15)
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B. Vanitha et.al.,/ International Journal of Engineering & Science Research
where
Mode 6 [t5–t6 ]: Mode 6 starts when QM is turned ON with ZVS. (Versus − VCB) + nVO2 is connected to the
spillage inductance, so the spillage current ilkg (t) is quickly expanded. At the point when ilkg (t) scopes to
iLm(t) + iLO1 (t)/n, this mode closes. ilkg (t), iLm(t), and iLO1 (t) can be communicated as takes
(16)
(17)
(18)
4. SIMULATION RESULTS
Simulation is performed using MATLAB/SIMULINK software. Simulink liabrary files include inbuilt models
of many electrical and electronics components and devices such as diodes, MOSFETS, capacitors, inductors,
motors, power supplies and so on. The circuit components are connected as per design without error, parameters
of all components are configured as per requirement and simulation is performed.
a) Wind turbine-generator set
b) Wind torque
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c)
Generated voltages
d) Converter output Vo1
e)
Converter output Vo2
f)
Simulation circuit
g) Current through SW-QA
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B. Vanitha et.al.,/ International Journal of Engineering & Science Research
h) Voltage across SW QA
i)
Current through SW1
j)
Voltage across SW1
5. CONCLUSION
A new multi-output converter configuration for PMSG wind energy system (WCS) is proposed here. Primary
side half-connect inverter and a flyback rectifier with additional buck converter are used. The size of
transformer can be reduced and switches life can be improved. This is studied using simulation in
MATLAB/SIMULINK.
REFERENCES
[1] Lin BR, Huang CL, Wan JF. Analysis, design, and implementation of a parallel ZVS converter. IEEE Trans.
Ind. Electron, Apr. 2008; 55(4): 1586–1594.
[2] Jung JH. Feed-forward compensator of operating frequency for APWM HB flyback converter. IEEE Trans.
Power Electron. Jan. 2012; 27(1): 211–223.
[3] Da Cunha Duarte C, Barbi I. A new family of ZVS-PWM active clamping DC-to-DC boost converters:
Analysis, design, and experimentation. IEEE Trans. Power Electron, Sep. 1997; 12(5): 824–831.
[4] Do HL. Zero-voltage-switching synchronous buck converter with a coupled inductor. IEEE Trans. Ind.
Electron, Aug. 2011; 58(8): 3440– 3447.
[5] Park JH, Cho BH. The zero voltage switching (ZVS) critical conduction mode (CRM) buck converter with
tapped inductor. IEEE Trans. Power Electron, Jul. 2005; 20(4): 762–774.
[6] Erickson RW, Maksimovic D. Fundamental of Power Electronics, 2nd ed. Norwell, MA, USA: Kluwer,
2001; 557–562.
[7] Yeh CA, Lai YS. Digital pulsewidth modulation technique for a synchronous buck DC/DC converter to
reduce switching frequency. IEEE Trans. Ind. Electron, Jan. 2012; 59(1): 550–561.
[8] Zhang Z, Eberle W, Liu Y, Sen PC. A non isolated ZVS asymmetrical buck voltage regulator module with
direct energy transfer. IEEE Trans. Ind. Electron, Aug. 2009; 56(8): 3096–3105.
[9] Jinno M, Chen P, Lai Y, Karada K. Investigation on the ripple voltage and the stability of SR buck converter
switch high output current and low output voltage. IEEE Trans. Ind. Electron, Mar. 2010; 57(3): 1008–1016.
[10] Jovanovic MM, Zhang MT, Lee FC. Evaluation of synchronous rectification efficiency improvement limits
in forward converter. IEEE Trans. Ind. Electron, Aug. 1995; 42(4): 387–395.
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