Direct AC-AC Full Bridge Converter

Transcription

1 OR Journal of Electrical and Electronic Engineering (OR-JEEE) e-n: ,p-N: PP Direct AC-AC Full Bridge Converter ofiya A 1, Renjit G, Mumta A 3 1 (At Prof, Dept. Of EEE,, Kollam) (At Prof, Dept. Of EEE,, Kollam) 3 (MTec colar, Dept. Of EEE, Rajiv Gandi ntitute Of Tecnology) Abtract: nduction eating are applied for everal indutrial and dometic application.among tee application it i mainly applied to dometic field a an induction cooker. n conventional induction eating application, efficiency and cot are compromied due to te conduction lo and increaed component. Te propoed topology wit full bridge converter ue only two diode reducing conduction lo and a direct ac-ac converion i poible ere. Te GBT i operated by a witcing frequency of 150KHz.. ntroduction nduction eating i emerging a te mot important application in power electronic..due to it ig temperature it i applicable to teel melting, brazing and urface ardening.dometic induction eating a become very relevant due to it iger efficiency and te reduced eating time.nduction eating wic i a non contact eating tecnique require ig-frequency current upply tat will induce a ig frequency eddy current in te working piece tat will reult in te eating effect. Power emiconductor witcing device, digital and analogue control device, circuit component and ig frequency oft witcing inverter are ued to bring out te unique advantage of induction eating into practical. Claical induction eating metod i baed on two tage: a rectifier and reonant inverter. A four-diode full bridge rectifier i ued to rectify te main ac voltage and a mall value dc-link capacitor to enure input power factor cloe to 1.Te reonant inverter upply te inductor pot ytem. Te one witc topology i motly ued for low cot appliance and low output power level, for medium output power alf bridge inverter i ued. Finally, te full bridge inverter i ued for ig output power level. Te propoed converter ue a alf bridge boot rectifier and a full bridge inverter for obtaining ig output power level. A reult converter efficiency i improved and low frequency ac current do not flow troug H load, tu reducing peak current and conduction loe. Full bridge topology a dual GBT(nulated gate bipolar tranitor) inverter module to convert AC ine wave o tat te ig frequency current waveform i complete, clear and table and due to te ig current allocation efficiency of full bridge topology it can electronically tranfer ig termal efficiency and can load ig inductive load.. Direct Ac-Ac Converter An ac-ac converter convert a fixed voltage, fixed frequency ac input upply to obtain a variable voltage ac output. n ac-ac converter inuoidal input current and bidirectional power flow can be acieved by coupling a pule widt modulation (PWM) rectifier and a PWM inverter to a dc link. Te DC link quantity i an energy torage element wic i a capacitor C for te voltage dc link and inductor for te current dc link.here we propoe a direct ac-ac converter for acieving ig frequency application. n conventional deign due to te input current armonic, a low frequency power get acro te load. o it take le eating time. Te need of an additional filter requirement i eliminated in te propoed model. Due to te activation of more tan one diode on eac alf cycle lead to ig conduction lo in cae of an conventional converter. Direct ac-ac converter i free from te conduction lo.. Block Diagram Te fig.1 ow te block diagram of Direct AC-AC Full Bridge Converter. Te input ac voltage i fed to AC-AC full bridge converter. Controller provide neceary gate ignal for te driver circuit. Driver circuit fix duty ratio of tee pule and it i driven to te reonant converter. Tu a ig frequency ac voltage i fed to te induction pan. 59 Page

2 Fig. 1. Block diagram of direct ac-ac full bridge converter. Circuit Diagram Te circuit diagram of direct ac-ac converter i own in fig.. We propoe full bridge ac-ac converter ere wic i more efficient tan alf bridge converter. Fig.. Circuit diagram of direct ac-ac converter Te converter conit of input AC voltage, four GBT witce 1,, 3, and 4, dc-link capacitor C, input inductor L, diode D,H D,L and H load. Te AC power upply i rectified by te alf-wave rectifier branc compoed of D,H and D,L.Te full bridge inverter circuit conit of four witce wit anti-parallel diode 1,, 3 and 4. Te witce 1and i ued bot to perform a boot dc dc converion of te main ac voltage and additionally, to upply te ig frequency current to te inductor along wit 3 and 4. Te voltage boot i performed by mean of te input inductor L and te dc-link capacitor Cb.Te H load i modelled a a erie of equivalent RL circuit compoed of Req and L eq. Te input inductor L and te dc-link capacitor Cb boot te voltage. Te boot dc-dc converion of main AC voltage i done by witce 1 and 3. Te wave form of te boot dc-dc circuit i own in fig.3. Fig. 3. Wave form of te boot dc-dc circuit. Ac-Ac Full Bridge Converter Analyi Te direct AC - AC converter operation can be analyzed troug te four mode of operation troug te equivalent circuit to. During te poitive alf cycle of te main voltage D H conduct tat i in indicated by te two tage and. Were a D L conduct during te negative alf cycle tat i indicated by te tage and. Ti ow tat only one rectifier i activated at a time,tat will reduce conduction lo a it i compared to te conventional converter. Te Zero voltage witcing i guaranteed in it by providing time delay between te witcing of eac witc. Te upply voltage i applied acro te inductor during te mode and and te dc link capacitor i carged by te inductor current during mode and. Te rectification for poitive upply voltage i done by witc 1 and for te negative cycle,it done by witc. Te required ig frequency AC current i o to upply te H load i performed by te inverter branc compoed of 1,, 3 and 4. Te equivalent full bridge inverter i upplied by te dc link capacitor voltage b. Te total current in te device i expreed a te um of te boot tage and te equivaent full bridge inverter tage. tage and te 60 Page

3 equivalent full bridge erie reonant inverter. n mode1 3 and 4 are turned on, D,H conduct during poitive alf cycle of current dc link capacitor i carged by te upply voltage and input inductor L. Te ig frequency current i applied acro te load. Mode 1 i own in figure.1 and 4 are turned on during mode, upply voltage i applied to te input inductor L. n mode 3 1 and are turned on D,L conduct and upply voltage and carge tored in te input inductor carge te dc link capacitor Cb. 3 and conduct during mode 4 and carge input inductor L. Mode, 3, 4 are own in figure 5, 6, 7 repectively. Tere are many advantage of direct converter over conventional converter tat te output frequency of direct AC - AC converter i iger becaue of te input current i free from armonic. Fig. 4. Mode of operation. Deign Of Full Bridge Converter Te input voltage i booted by te input inductor L and dc link capacitor C b. Te witc 1 and 3 perform te boot dc to dc converion. Te dc dc boot circuit waveform are own in Fig.7,were te teady tate average input current i. n order to avoid te current ripple and ig frequency current troug te rectifier diode, a continuou current mode i aumed. n teady tate average voltage acro inductor i zero. DT w 1 DT 0 b w Te ratio of voltage converion i ame a te boot converter. (1) b 1 () 1 D Te input current of te temporal waveform can be calculated uing te input current rippl Δ,, D, 0 DT (3) L Were te minimum and maximum input current value during a witcing period i,0 and,d repectively. Conequently, te input current of te temporal waveform i reult ( t) DT DT t,(0 t DT ( t DT ) ),( DT t T ) (4) 61 Page

4 Te condition of CCM i atified a, CCM,0 0 (5) Te input power P in for an unity power factor i aumed P in DT (6) L tat will lead to, P in DT (7) L Direct AC-AC Full Bridge Converter o tere i a trade off between te input power, te input inductor value, and modulation parameter for a given upply voltage level to enure CCM. Te full bridge erie reonant inverter conit of four witce 1,, 3 and 4. t i upplied by te output voltage of te boot tage b. By uing te Fourier armonic analyi, te output power Po reult 1 o, 0, rm, P o R eq R eq 0 Zo, 0 Zo, (8) Req o, 0 1 Req fleq f Cr were i te armonic number, Zo i te impedance of te erie RLC reonant tank, and o i te output voltage of te inverter. t inuoidal peak voltage reult ˆ b 0, a b (9) Were coefficient of fourier erie are, a in( D), b Te output power reult, 0 P 0 1co( D) 1 co( D) Req (1 D) (10) R eq f 1 Leq f Cr. imulation Of Full Bridge Converter Te imulation of full bridge converter i obtained in MATLAB.imulation diagram i own in fig.5. Te ig frequency output voltage acro te load i own in fig.6 Table : Deign Parameter 6 Page

5 Fig. 5. imulation of full bridge converter Fig. 6. Output oltage waveform Fig. 7. oltage & current acro Diode Fig. 8. oltage & current acro GBT Te voltage and current acro Diode i own in Fig.7. Tere i only one diode i activated at a time o it will reduce conduction lo.due to te reduction of non-linear load in te input, input current i free from armonic.te oltage and current acro GBT are own in fig.8. 1 and 3 conduct 50 percent during poitive alf cycle. and 4 conduct 50percent during negative alf cycle. 63 Page

6 . Hardware Platform Fig.9. Haedware etup Table : Hardware Requirement Component pecification GBT RF540 Driver C TLP 50 Capacitor 470nF Diode N4007 nductor 155μH Microcontroller ATMEGA 16 n ardware ection conit of a Rectifier ection inverter ection (H-Bridge inverter), driver circuit,microcontroller for giving pule, and an induction coil. Te witcing pule for to witc correponding GBT are obtained in DO are own in fig.10 Fig. 10. witcing pule Fig. 11. Output oltage 64 Page

7 X. Concluion A full bridge AC-AC reonant converter for induction eating application i propoed ere. Te key feature of te propoed converter are reduced component count and ig efficiency. Te converter can operate wit zero voltage witcing. A a reult power converter i improved in wole operating range. Te ardware i preented uing AR microcontroller a a prototype model. Reference [1]. Hector arnago, tudent Member, EEE, Ocar Lucia, Member, EEE, Arturo Mediano, enior Member, EEE, and Jo em.burdio, enior Member, EEE, Direct AC AC Reonant Boot Converter for Efficient Dometic nduction Heating Application, EEE TRANACTON ON POWER ELECTRONC, OL. 9, NO. 3, MARCH 014. []. arnago, O. Lucia Gil, A. Mediano, and J. M.Burdio, Modulation ceme for improved operation of an RB-GBT-baed reonant inverter applied to dometic induction eating, EEE Tran. nd. Electron., vol. 60, no. 5, pp , May 013. [3]. O. Lucia, J. M. Burd io,. Mill an, J. Acero, and D. Puyal, Load-adaptive control algoritm of alf-bridge erie reonant inverter for dometic in-duction eating, EEE Tran. nd. Electron., vol. 56, no. 8, pp , Aug [4]. O. Luc ia, J. M. Burd io,. Mill an, J. Acero, and L. A. Barrag an, Efficiency oriented deign of Z alf-bridge erie reonant inverter wit variable frequency duty cycle control, EEE Tran. Power Electron., vol. 5, no. 7, pp , Jul [5]. Yilmaz, M. Ermi, and. Cadirci, Medium-frequency induction melting furnace a a load on te power ytem, EEE Tran. nd. Appl., vol. 48, no. 4, pp , Jul./Aug. 01. [6]. J. Egalon,. Caux, P. Mauion, M. ouley, and O. Pateau, Multipae ytem for metal dic induction eating: Modeling and RM current control, EEE Tran. nd. Appl., vol. 48, no. 5, pp , ep./oct. 01. [7]. Millan,J.M.Burd io, J. Acero, O. Luc ia, and. Llorente, erie reonant inverter wit elective armonic operation applied to all-metal dometic induction eating, ET Power Electron., vol. 4, no. 5, pp , May 011. [8]. O. Lucia, J. M. Burd io, J.. Mill an, J. Acero, and L. A. Barrag an, Efficiency-oriented deign of Z alf-bridge erie reonant inverter wit variable frequency duty cycle control, EEE Tran. Power Electron., vol. 5, no. 7, pp , Jul Page