comparative evaluation of single-phase unity power factor

Comparative Evaluation of Single-phase Unity Power Factorac-dc Boost Converter Topologies

A Pandey, Non-memberProf B Singh, FellowProf D P Kothari, Fellow

This paper presents a comparative evaluation of five topologies of single-phase ac-dc boost converters having powerfactor correction (PFC). These converter topologies are evaluated on the basis of performance and their salient featuresare discussed to analyze their applicability. Operation of these converters and their control schemes are described andmodeled using first-order differential equations. Performance of these converters is simulated and conformity of theseconverters is shown to relevant international standards. This work aims to provide an exposure of PFC converters toresearchers and application engineers dealing with power quality issues.

Keywords: ac-dc power converter; PFC; Power quality improvement; Comparative study

A Pandey and Prof D P Kothari are with Centre for Energy Studies andProf B Singh is with Department of Electrical Engineering, IIT Delhi,Haus Khus, New Delhi 110 016.

This paper (redrafted) was received on July 4, 2003. Written discussion on thispaper will be received until November 30, 2004.

INTRODUCTIONSingle-phase switch mode ac-dc converters are being used asfront-end rectifiers for a variety of applications due to theadvantages of high efficiency and power density. Theseclassical converters, however, draw-non-sinusoidal input accurrents leading to low input power factors and injection ofharmonics into the utility lines1. Research in improved powerquality utility interface has gained importance due to stringentpower quality regulation and strict limits on total harmonicdistortion (THD) of input current placed by standards such asIEC 61000-3-2 and IEEE 519-19922. This has led to consistentresearch in the various techniques for power qualityimprovement. Research into passive and active techniques forinput current wave shaping has highlighted their inherentdrawbacks. Passive filters have the demerits of fixedcompensation, large size and resonance whereas the use ofactive filters is limited due to added cost and controlcomplexity3.

Research into switch mode power factor corrected ac-dcconverters has been in two directions namely buck and boosttype topologies1. The advantage of Buck type topology is thatthe converter can provide variable output voltage, which islower than the input voltage. However, when theinstantaneous input voltage is below the output voltage thecurrent drops to zero and the results in significant increase ininput current THD4.

Design of input filters for power factor improvement in buckconverters is therefore complex and provides only limited im-provement in input current quality. On the other hand theboost type converter generate dc voltage, which is higher than

the input ac voltage. However, the input current in theseconverters flows through the inductor and therefore can easilybe actively wave-shaped with appropriate current modecontrol. Moreover, boost converters provide regulated dcoutput voltage at unity input power factor and reduced THDof input ac current. These converters have found widespreaduse in various applications due to the advantages of highefficiency, high power density and inherent power qualityimprovement at ac input and dc output.

The preferred power circuit configuration of single-phaseboost converter5-18 is the most popular and economical PFCconverter consisting of diode bridge rectifier with step-upchopper. Problems like low efficiency and reduced reliabilityare addressed in subsequent work19-22. Where the semi-boostconverter topologies offers several advantages over basic boosttopology in terms of reduced input current THD, higherefficiency and reliability. Half-bridge converter topology23-28

further enhances the efficiency and performance in sometypical applications. Whereas, the single-phase voltage sourceconverter (VSC) topology with bi-directional power flowcapability29-37 finds application in drives with regenerativebreaking, line interactive uninterruptible power supply (UPS),static VAR compensator and battery energy storage system.This paper provides a comparative study of single-phase PFCtopologies for applications where isolation is not required.Complete mathematical modelling of PFC converters iscarried out. Simulation results are provided for evaluation ofconverter performance under steady state and dynamicconditions and performance of single-phase boost converter isthen experimentally verified. Finally, the converters arecompared on the basis of performance, efficiency, design andcontrol complexity.

CIRCUIT CONFIGRATIONSPFC converter topologies considered in this work aredescribed in this section. The single-phase boost converter

102 IE (I) Journal�EL

with uni-directional power flow shown in Figure 1(a), isrealized by cascading single-phase diode bridge rectifier withboost chopper topology. Another topology with uni-directional power flow, semi-boost converter topology isshown in Figures 1(b) and 1(c). These configurations areimplemented with two semi-conductor switches and twodiodes. The inductor L is on the input side. Figures 1(d) and1(e) show half-bridge boost converter and voltage sourceconverter based on half-bridge and full bridge topologies, re-spectively. These two topologies allow bi-directional powerflow.

CONTROL SCHEMEThe objective of the control scheme of the boost converters isto regulate the power flow ensuring tight output voltageregulation as well as unity input power factor. Cascadedcontrol structure shown in Figure 1(f) is the most extensivelyused control scheme for these converters and essentiallysimilar control philosophy is applied to all the othertopologies of boost converter. In this scheme, the output ofvoltage regulator, limited to a safe value, forms the amplitudeof input reference current. This reference amplitude is thenmultiplied to a template of input voltage to synchronize thereference with input voltage, as required for unity powerfactor operation. The inductor current is forced to track itsreference current using current controller, which generatesappropriate gating signals for the active device(s).

MATHEMATICAL MODELLING OF PFCCONVERTERSThe proposed PFC converter system comprises single-phaseac supply, power converter circuit, and control scheme. In thissection modelling equations of various components of theconverter system are formulated separately to develop acomprehensive model for their performance simulation.

Supply SystemUnder normal operating conditions the supply system can bemodeled as a sinusoidal voltage source of amplitude Vm andfrequency fs . The instantaneous voltage is given as:

vs (t) = V tm sin ω (1)

where ω π= 2 f ts electrical rad/s and t is instantaneous time.

From sensed supply voltage, a template u(t) is estimated forconverter topologies with ac side inductor.

u t v t Vs m( )= ( ) / (2)

Figure 1(a) Boost converter

Figure 1(b) Symmetrical semi-boost converter

vs

is L

s

Cd

vdc

idc

Load

Figure 1(c) Asymmetrical semi-boost converter

Figure 1(d) Half bridge converter

vs

is L

s

Cd

vdc

idc

Load

Figure 1(e) VSC converter

vs

is L

s

Cd

vdc

idc

Load

vs

is L

s

Cd v

dc

idc

Load

vs

is

Ls

Cd

vdc

idc

Load

Figure 1(f) Control scheme of PFC converter

C1

C2

Vol 85, September 2004 103

Ü

u(t)

vs

is L

Cd

Idc

vdc LOAD

Vdc

Vdc

*PI

A

BC

AB/C2

LP Filter

is

ien

LP Filter

is*

u(t) for converter topologies with dc side inductor is obtainedfrom:

u t v t Vs m( ) ( ) /= (3)

DC Voltage ControllerThe objective of dc voltage controller is described earlier. Aproportional integral (PI) voltage controller is selected forvoltage loop for tight regulation of the output voltage. The dcvoltage vdc is sensed and compared with set reference voltagev dc

* . The resulting voltage error ve(n) at nth sampling instant is:

ve(n) = −v vdc dc n*

( ) (4)Output of PI voltage regulator v0(n) at nth sampling instant is:

v0(n) = + − +− −v K v v K vn p e n e n i e n0 1 1( ) ( ) ( ) ( )( ) (5)

where K p and Ki are the proportional and integral gainconstants. ve (n � 1) is the error at the (n � 1)th sampling instant.The output of the controller v0(n) after limiting to a safepermissible value is taken as amplitude of reference supplycurrent A.

PWM Current RegulatorCurrent regulation loop is required for active wave shaping ofinput current to achieve unity input power factor and reducedharmonics.

Reference Supply Current GenerationThe input voltage template B obtained from sensed supplyvoltage is multiplied with the amplitude of reference sourcecurrent A in the multiplier-divider circuit. Moreover, acomponent of input voltage feedforward C is also added toimprove the dynamic response of the converter system to linedisturbances (Figure 1(f)). The resulting signal forms thereference for input current. The instantaneous value of thereference current is given as:

i AB Cs* /= 2 (6)

Active Wave-shaping of Input Current

The inductor current error is the difference of reference

supply current and inductor current ( )*i i ien s s= − . This errorsignal is amplified and compared to fixed frequency carrierwave to generate gating signals for power devices of theconverter. PWM switching algorithm is selected depending onthe converter topology.

Modelling of PFC ConvertersThe converters are modelled using first order non-lineardifferential equations. The number of equations is equal to thenumber of energy storage components in the system.Single-phase Boost PFC ConverterThe boost converter is modelled using two differentialequations for inductor current iL and dc link capacitor voltagevdc .

p i v v L r i LL d p L= − −( ) / ( / ) (7)

p v i v R Cdc p dc d= −( / )/ (8)

where p is the differential operator (d/dt); r, the resistance ofthe inductor L; vd , the rectified line voltage at diode rectifieroutput; R, the resistance of the load and vp is the PWM voltageacross the switch and is defined as

vp = vdc (1 � S) (9)

ip is the current through the boost diode and is defined as

ip = iL (1 � S) (10)

where S is the switching signal obtained from current regula-tion loop. Its value is 1 (ON) or 0 (OFF) depending upon thestate of the switch.

Single-phase Semi-boost ConverterTwo variants of semi-boost converter topologies areconsidered, ie, symmetrical and asymmetrical. Both typeshave identical characteristics. The variations lead to simplifiedcurrent regulation in the symmetrical variant. The converteris described by two differential equations for inductor currentiL and dc link voltage across capacitor vdc .

p i v v r i LL s p L= − −( ) / (11)

p v i v R Cdc p dc d= −( / )/ (12)

where PWM voltage and current are as:

vp = −v S Sdc ( )1 2 (13)

i i S Sp L= −( )1 2 (14)

respectively;

where S1 and S2 are switching states of switches S1 and S2,respectively.

Single-phase Half-bridge Converter

There are three modelling equations describing the model ofthe converter as:

p i v v v r i LL s p p L= + − −( ) /1 2 ; (15)

pv i v R CC p dc1 1 1= − +{ ( / )}/ ; (16)

pv i v R CC p dc2 2 2= −{ ( / )}/ ; (17)

dc link voltage is as:

vdc = +( )v vC C1 2 (18)

and the PWM voltages and current are as

i S ip L1 1= (19)

i S ip L2 2= (20)

vp1 = S vC1 1 (21)

vp2 = S vC2 2 (22)

here S1 and S2 are switching states of respective switches.


Single-phase Voltage Source Converter

The converter is described by two differential equations forinductor current iL and dc link voltage across capacitor vdc .

p i v v r i LL s p L= − −( ) / (23)

p v i v R Cdc p dc d= −( / )/ (24)

where PWM voltage and current are

vp = −v Sa Sbdc ( ) (25)

i i Sa Sbp L= −( ) (26)

respectively;where

Sa = 1 if switches S1 and S4 are ON, otherwise Sa = 0.Sb = 1 if switches S2 and S3 are ON, otherwise Sb = 0.

PERFORMANCE CHARACTERISTICSPerformance simulation of converters modelled and describedin the previous section is carried out for different loadingconditions at 100-kHz switching frequency. The values ofinductor and capacitor are calculated for desired input currentripple and output voltage ripple. A summery of performanceevaluation and topology features is presented in Tables 1 and2, respectively.

Steady-State and Dynamic PerformanceAll five topologies considered in this work provide smooth dcvoltage at a power factor close to unity and show excellentsteady state and dynamic characteristics (Figures 2-5). Inputcurrent THD is well below the limits stipulated by IEC61000-3-2 and other standards. These converters exhibit satisfactoryvoltage regulation at load variations from 325 W to 1625 W ofnominal. This makes these converters suitable for applicationswith significant load variation. Half-bridge converter andvoltage source converter exhibit best characteristics in termsof dc voltage regulation and input current THD. Input currentdistortion at zero crossovers is also non-existent in theseconverters.

Table 1 Summery of performance evaluation

Rectifier THD, % Power Factor Rise/Dip Settling Heavy Light Heavy Light in Output Time Load Load Load Load Voltage, Load % Applica- tion/ removal, ms

Boost 0.3917 1.0572 1.000 0.999 2.41/3 47/47

Semi-boost 0.4789 1.8680 1.000 0.999 2.41/3 47/47

Half-bridge 0.4394 1.8137 1.000 0.999 2.8/3.4 27/37

VSC 0.4699 1.9093 1.000 0.999 2.41/3 37/27

Table 2 Summery of topology/efficiency evaluation

Rectifier Number of Number of Number of Power FlowPower Diodes Voltage

Switches DropAcrossSemi-

conductorDevices

Boost 1 5 3 unidirectional

Semi-boost 2 4 2 unidirectional

Half Bridge 2 2 1 bi-directional

VSC 4 4 2 bi-directional

Figure 2(a) Dynamic performance of single-phase boost converter

Figure 2(b) Harmonic spectrum of input current for single-phase boostconverter at light load (325 W)

2

1.5

1

0.5

00 10 20 30 40 50 60

Mag

nitu

de, A

Harmonic Order


Time, s

200

0

� 200 0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

10

0

� 10

450

400

350

5

0

Outp

ut

Curr

ent,

A

Outp

ut

Volta

ge,

VIn

put

Curr

ent,

AIn

put

Volta

ge,

V

Figure 2(c) Harmonic spectrum of input current for single-phase boostconverter at heavy load (1625 W)

0 10 20 30 40 50 60

Harmonic Order

Mag

nitu

de, A

10

9

8

7

6

5

4

3

2

1

0

Figure 3(a) Dynamic performance of single-phase semi-boost converter

2

1.5

1

0.5

00 10 20 30 40 50 60

Mag

nitu

de, A

Harmonic Order

Figure 3(b) Harmonic spectrum of input current for single-phasesemi-boost converter at light load (325 W)

Figure 3(c) Harmonic spectrum of input current for single-phase semi-boost converter at heavy load (1625 W)

0 10 20 30 40 50 60Harmonic Order

Mag

nitu

de, A

10

9

8

7

6

5

4

3

2

1

0

200

0

� 200 0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

10

0

� 10

450

400

350

5

0

Time, s

Outp

ut

Curr

ent,

AO

utp

ut

Volta

ge,

VIn

put

Curr

ent,

AIn

put

Volta

ge,

V


Figure 4(a) Dynamic performance of single-phase half-bridge converter

0 0.05 0.1 0.15 0.2 0.25

0 0.05 0.1 0.15 0.2 0.25

2

1.5

1

0.5

00 10 20 30 40 50 60

Mag

nitu

de, A

Harmonic Order

Figure 4(b) Harmonic spectrum of input current for single-phase half-bridge converter at light load (325 W)

200

0

� 200

10

0

� 10

720

700

680

5

0

Time, s

Outp

ut

Curr

ent,

AO

utp

ut

Volta

ge,

VIn

put

Curr

ent,

AIn

put

Volta

ge,

V

0 0.05 0.1 0.15 0.2 0.25

0 0.05 0.1 0.15 0.2 0.25

0 10 20 30 40 50 60Harmonic Order

Mag

nitu

de, A

10

9

8

7

6

5

4

3

2

1

0

Figure 4(c) Harmonic spectrum of input current for single-phasehalf-bridge converter at heavy load (1625 W)

0 10 20 30 40 50 60Harmonic Order

Mag

nitu

de, A

10

9

8

7

6

5

4

3

2

1

0

Figure 5(b) Harmonic spectrum of input current for single-phase voltagesource converter at light load (325 W)

Figure 5(c) Harmonic spectrum of input current for single-phase voltagesource converter at heavy load (1625 W)


Figure 5(a) Dynamic performance of single-phase voltage sourceconverter

2

1.5

1

0.5

00 10 20 30 40 50 60

Mag

nitu

de, A

Harmonic Order

EfficiencyVoltage drops across semi-conductor devices can havesignificant effect on the overall efficiency of the converters.Number of voltage drops across single-phase boost converteris three, whereas it�s reduced to two in semi-boost and voltagesource topologies. In half-bridge topology its further reducedto one thereby improving the efficiency considerably.However, this improvement in efficiency is achieved atincreased cost of additional active switches and fast recoverydiodes. Low efficiency of half-bridge converters inapplications requiring bi-directional power flow cannot beavoided as the capacitors are discharged into supply.

APPLICATION POTENTIAL OF PFC CONVERTERSBoost Converter is most economical and optimal converter interms of performance and efficiency and providesunidirectional power flow. This converter is used as powerfactor pre-regulators for power supplies, electronic ballast andlow power drive applications where bi-directional power flowis not required.Semi-boost topologies are used in applications whereefficiency is critical. These converters provide increasedefficiency at the cost of added design and control complexity.These converters are however, identical to boost converter interms of performance. Half bridge toplogy is used for drives/on-line UPS applications. This converter provides a step up

ratio of 2 2 at very high efficiency and excellent dynamiccharacteristics.Single-phase voltage source converter is used for applicationswhere bi-directional power flow is required. This converterhas found use in traction drives, UPS etc. It has excellentdynamic characteristics and operates at high efficiency.

EXPERIMENTAL TESTING OF SINGLE-PHASEBOOST CONVERTERPerformance of single-phase boost converter is experimentallytested to identify the numerous non-topological factors that

Time, s

200

0

� 200 0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

0 0.05 0.1 0.15 0.2 0.25 0.3

10

0

� 10

450

400

350

5

0

Outp

ut

Curr

ent,

A

Outp

ut

Volta

ge,

VIn

put

Curr

ent,

AIn

put

Volta

ge,

V

Figure 6 Input current and voltage waveforms of diode rectifier

Figure 7(a) Input voltage and current waveforms of single-phase boostconverter

connections. Moreover, incorporating these factors inmathematical model can complicate analysis and simulation.

CONCLUSION

Modelling and simulation of PFC converters are carried outand single phase boost converter is experimentally tested toverify the simulation results and identify the numerousreasons impacting PFC converters in general. Performanceand applicability of these converters are presented on the basisof simulated results under identical line and load conditions. Acomprehensive summery of performance indices andtopological features are provided. From the study it can beinferred that single-phase boost topology is optimal in terms ofperformance, efficiency, cost and power density and istherefore suitable for most applications. Half-bridge toplogy isthe most efficient topology with excellent performance. Itsapplication is however limited due to restriction on minimumstep-up ratio of 2 2 and low efficiency during inverter mode.Semi-boost topologies provide excellent performance and highefficiency for power factor pre-regulator applications forswitched power supplies and drives systems albeit at highercost of implementation and control. Voltage source convertersoffer bi-directional power flow at high efficiency and variablepower factor. The potential applications of VSC can be UPS,static VAR compansator, and battery charging.

ACKNOWLEDGEMENTFirst named author expresses sincere thanks to the Council ofScientific and Industrial Research for the financial assistanceprovided under Award No 9/86(456)/2000-EMR-I to carryout this research.

REFERENCES1. J D Van Wyk. �Power Quality, Power Electronics and Control.� inProceedings EPE.93, 1993, pp 17-32.

2. Z Yang and P C Sen. �Recent Developments in High Power Factor Switch-mode Converters.� in IEEE Proceedings CCECE.98, 1998, pp 477-480.

3. H Akagi. �New Trends in Active Filters for Power Conditioning.� IEEETransactions Industry Applications, vol 32, November/December 1996,pp 1312-1322.

4. H Endo, T Yamashita and T Sugiura. �A High Power-factor BuckConverter.� in Proceedings IEEE PESC�92, 1992, pp 1071-1076.

Figure 7(b) Output voltage waveform of single-phase boost converter


can impact the quality of current drawn by these converter aswell as to develop greater confidence in the simulation studiescarried out in the paper. A Texas Instrument IC-UC3854Apower factor controller based implementation is carried out for a500 W, universal line (80 V-270 V) single-phase boostconverter. The power circuit is fabricated with IRFP460MOSFET and MUR460 fast recovery diode with Ls = 1.1 mHand C d = 560µF . The converter is fed from ac lines via anautotransformer followed by an isolation transformer toprovide variable input voltage and protection, respectively.Figure 6 shows the distortion in the input voltage caused bydistorted current when the system is operated as anuncontrolled diode bridge rectifier. Harmonic currentinteracting with the source impedance, primarily due toutility lines and transformers, causes this distortion. Thisdistortion is corrected by triggering the power factorcontroller and waveshaping the input current into desiredsinusoid as shown in Figure 7(a). The input current andvoltage waveforms shown in Figure 7 matches with thesimulation results shown in Figure 2. This validates the mathe-matical model as well as simulation tools used in thecomparative evaluation.

The input current THD of the boost converter is slightlylower under simulated conditions as several factors like non-linearity in multiplier, source impedance, deviation of inputvoltage from desired sinusoidal shape, addition of EMI filter,tolerances in passive components and limited bandwidth andnon-linearity in sensor circuits were neglected in developingthe mathematical model of the converter for performancesimulation. These factors have a very local influence and canvary significantly in different systems as well as utility

5. S K Mazumder, A H Nayfeh and D Borojevic. �A Novel Approach to theStability Analysis of Boost Power-factor-correction Circuits.� in ProceedingsIEEE PESC�01, 2001, pp 1719-1.

6. L G Lopez, de Vicuna and M Castilla. �Sliding Mode Control Design of aBoost High-power-factor Pre-regulator Based on the Quasi-steady-sateApproach.� in Proceedings IEEE PESC�01, 2001, pp 932-935.

7. S B Monge, C Crebier, S Ragon, E Hertz, J Wei, J Zhang, D Boroyevich andZ Gilrdal. �Optimization Techniques Applied to the Design of a Boost PowerFactor Correction Converter.� in Proceedings IEEE PESC�01, 2001, pp 920-925.

8. L Ping and K Yong. �Design and Performance of an ac/dc Voltage SourceConverter.� in Proceedings IEEE INTELEC�00, 2000, pp 419-423.

9. H S H Chung, S Y R Hui and D Y Qiu. �Control of Active Power-factorCorrector using a Single Current Sensor.� in Proceedings IEEE PESC�00, 2000,pp 577-582.

10. H S H Chung, S Y R Hui and D Y Qiu. �Control of Active Power-factorCorrector using a Single Current Sensor.� in Proceedings IEEE PESC�00, 2000,pp 577-582.

11. M Fu and Q Chen. �A DSP Based Controller for Power Factor Correction(PFC) in a Rectifier Circuit.� in Proceedings IEEE APEC�01, 2001, pp 144-149.

12. R Zane and D Maksimovic. �A Mixed-singal ASIC Power-factor-correction(PFC) Controller for High Frequency Switching Rectifiers.� in ProceedingsIEEE PESC�99, 1999, pp 117-122.

13. T -Fu Wu, T -W Yu and Y -J Wu. �A Microprocessor-based Toggle-controlLighting System.� IEEE Transactions Industrial Electronics, vol 45, June 1998,pp 525-528.

14. M Kazerani, P D Ziogas and G Joos. �A Novel Active Current WaveShaping Technique for Solid-state Input Power Factor Conditioners.� IEEETransactions Industrial Electronics, vol 38, February 1991, pp 72-78.

15. T C Chen and C T Pan. �Modelling and Design of a Single Phase ac to dcConverter.� IEE Proceedings, vol 136, September 1992, pp 465-470.

16. M Morimoto, K Oshitani, K Sumito, S Sato, M Ishida and S Okuma. �NewSingle-phase Unity Power Factor PWM Converter-inverter System.� in IEEEPESC�89, 1989, pp 585-589.

17. D Abud, F Canles and J Arau. �Design of Two Stage, 1 kW ac/dc Power-factor Pre-regulator using the FB-ZVS-PWM Topology.� in Proceedings IEEECIEP�93, 1993, pp 129-134.

18. G Venkataramanan. �A Direct ac-dc Converter for Battery Chargers.� inProceedings IEEE PESC�97, 1997, pp 126-130.

19. D Xu and F C Lee. �Two-lower-switch PFC Converter with ActiveSnubber.� in Proceedings IEEE PESC�01, 2001, pp 942-946.

20. J Rajagopalan, F C Lee and P Nora. �A General Technique for Derivation ofAverage Current Mode Control Laws for Single-phase Power-factorCorrection Circuits without Input Voltage Sensing.� IEEE Transactions PowerElectronics, vol 14, July 1999, pp 663-672.

21. S Manias. �Novel Full Bridge Semi Controller Switch Mode Rectifier.� IEEProceedings, vol 13, September 1991, pp 252-256.

22. J -H Youm, H -L Do and B -H Kwon. �A Single-stage Electronic Ballast withHigh Power Factor.� IEEE Transactions Industrial Electronics, vol 47, June 2000,pp 716-718.

23. G V Covic, G L Peters and J T Boys. �An Improved Single Phase to ThreePhase Converter for Low Cost ac Motor Drives.� in Proceedings IEEE PEDS�95,1995, pp 549-554.

24. W J Ho, J B Lio and W S Feng. �A Line-interactive UPS Structure withBuilt-in Vector-controlled Charger and PFC.� in Proceedings IEEE PEDS�97,1997, pp 127-132.

25. G J Su, D J Adams, L M Tolbert. �Comparative Study of Power FactorCorrection Converters for Single-phase Half-bridge Inverters.� in ProceedingsIEEE PESC�01, 2001, pp 995-1000.

26. R Srinivasan and R Oruganti. �A Unity Power Factor Converter using Half-bridge Boost Topology.� IEEE Transactions Power Electronics, vol 13, June 1997,pp 487-500.

27. J T Boys and A W Green. �Current-forced Single-phase ReversibleRectifier.� IEE Proceedings, vol 136, September 1989, pp 205-211.

28. A I Takahashi and K Utsunomiya. �A Simple Sensorless Method forSinusoidal PWM Converters.� in Proceedings IEEE PCC-Nagaoka�97, 1997,pp 241-246.

29. M Y Chang, J Y Lin and Y Y Tzou. �DSP Based Fully Digital Control forac dc Converter with a Non-linear Digital Current Mode Control.� inProceedings IEEE PESC�96, 1996, pp 1702-1708.

30. G V Covic, G L Peters and J T Boys. �An Improved Single Phase to ThreePhase Converter for Low Cost ac Motor Drives.� in Proceedings IEEE PEDS�95,1995, pp 549-554.

31. M G Kim, W C Lee and D S Hyun. �Instantaneous Control of a Single-phaseP/VM Converter Considering the Variation of Observer Parameter.� inProceedings IEEE IECON�97, 1997, pp 839-844.

32. F Flinders and W Oghanna. �Simulation of a Complex Traction PWMRectifier using SIMULINK and the Dynamic Node Technique.� in ProceedingsIEEE IECON�97, 1997, pp 738-743.

33. F Flinders and W Oghanna. �The Characteristics of a New Model BasedController for Single-phase PWM Rectifier.� in Proceedings IEEE IECON�97,1997, pp 895-900.

34. Y Miyashita, T Nishida, O E Ohtsuji and T Haneyoshi. �High PowerFactor PWM Rectifier with Analog Pulse-width Predictor.� in Proceedings IEEEAPEC�94, 1994, pp 563-568.

35. T Shimizu, Y Jin and G Kimura. �dc Ripple Current Reduction on a Single-phase PWM Voltage Source Rectifier.� in Proceedings IEEE IAS�99, 1999,pp 810-817.

36. O Stihi and B T Ooi. �A Single-phase Controlled-current PWM Rectifier.�IEEE Transactions Power Electronics, vol 3, October 1988, pp 453-459.

37. T Shimizu, T Fujita, G Kimura and J Hirose. �Unity-power-factor PWMRectifier with dc Ripple Compensation.� in Proceedings IEEE IECON�94, 1994,pp 657-662.


comparative evaluation of single-phase unity power factor

Documents