Novel current mode AC/AC converters with high frequency ac link *

Transcription

1 vel current mde AC/AC cnverters wth hgh frequency ac lnk * Dalan Chen, e, Jan u, Shengyang n, Chen Sng Department f Electrcal Engneerng, anjng nversty f Aernautcs & Astrnautcs, anjng, Jangsu, 006 P.R.Chna E-mal: chendalan@htmal.cm Abstract : A nvel crcut tplges famly f the current mde AC/AC cnverter wth hgh frequency ac lnk, based n Flyback cnverter, are prpsed. These crcut tplges whch can transfer ne unregulated snusdal vltage wth hgh THD nt anther regulated cnstant frequency snusdal vltage wth lw THD, are cnsttuted f nput cyclcnverter, hgh frequency strage transfrmer and utput cyclcnverter. The crcut tplges famly nclude sngle fur-quadrant pwer swtch mde,push-pull mde,half-brdge mde,and fullbrdge mde crcut. The sngle fur-quadrant pwer swtch mde and push-pull mde cnverter are sut fr lw nput vltage felds,but the half-brdge mde and fullbrdge mde cnverter are sut fr hgh nput vltage felds.the peratnal mde, steady prncple and transent vltage feedback cntrl strategy f the knd f cnverter are nvestgated. The utput characterstc curve, ts relatn t nternal resstance, and the desgn crterns fr the key crcut parameters are gven. The current mde AC/AC cnverters wth hgh frequency ac lnk have the advantages such as smple tplgy, tw-stage pwer cnversns, b-drectnal pwer flw, hgh frequency electrcal slatn, gd lne current wavefrm, strng lad adaptng ablty. The crrectn and advance f the cnverters are verfed by the Pspce smulatn and test results. Ⅰ.TRODCTO The hgh frequency lnk DC/DC cnverters, the hgh frequency lnk AC/DC cnverters (swtchng mde rectfers), and the hgh-frequency lnk DC/AC nverters [] have been deeply nvestgated and well knwn. Hwever, the research n AC/AC cnverters are manly lmted t the thyrstr phase-cntrlled cyclcnverters [] and the matrx cnverters [3] wthut electrcal slatn. The crcut cnfguratn and tplgcal famly f the vltage mde AC/AC cnverter wth hgh frequency AC lnk based n Frward cnverter were prpsed n the paper [4,5],whch have the advantages such as tw-stage pwer cnversns, bdrectnal pwer flw, hgh frequency electrcal slatn, gd lne current wavefrm, strng lad adaptng ablty, and beng sut fr medum r large pwer feld. f a crcut tplgy f AC-AC type hgh frequency lnk AC/AC cnverter wth smpler tplgy,hgher relablty lwer cst and applcablty n small pwer cnversns felds can be fnd? A famly f the current mde AC/AC cnverters wth hgh frequency AC lnk based n Flyback cnverters, whch can transfer ne unregulated snusdal vltage wth hgh THD nt anther regulated cnstant frequency snusdal vltage wth lw THD, are prpsed and deeply nvestgated n ths paper. The peratnal mde, steady prncples and transent vltage feedback cntrl strategy f the cnverter are nvestgated. The utput characterstc curve, ts relatn t nternal resstance, the desgn crterns fr the key crcut parameters, smulatn and test results are gven. The cnverters lay key techncal fundatn n new-type regulated snusdal ac pwer supples and electrnc transfrmers. Ⅱ CRCT TOPOOGES FAMY AD COTRO STRATEGY A Crcut Structure And Crcut Tplges Famly The crcut structure and crcut tplges famly f the current mde AC/AC cnverters based n the Flyback cnverter are shwn n Fg.. Ths crcut structure, whch can transfer ne unregulated snusdal vltage wth hgh THD nt anther regulated cnstant frequency snusdal vltage wth lw THD, s cnsttuted f nput cyclcnverter, hgh frequency strage transfrmer and utput cyclcnverter. nput cyclcnverter s made up f fur-quadrant pwer swtches, Output cyclcnverter s made up f tw-quadrant pwer swtches. The crcut tplges famly shwn n fg. nclude sngle fur-quadrant pwer swtch mde,push-pull mde,half-brdge mde,and full-brdge mde crcut, where S (S ),S (S ),S 3 and S 4 are pwer swtch, S a (S a ) and S a (S a ) are auxlary swtch whch can clamp spke vltage caused by the leakage nductance energy f the transfrmer. The sngle fur-quadrant pwer swtch mde and push-pull mde cnverter are sut fr lw nput vltage felds,but the half-brdge mde and full-brdge mde cnverter are sut fr hgh nput vltage felds. f energy s transferred frm surce t lad, nput cyclcnverter wll mdulate lw frequency ac vltage nt * Ths paper s supprted by atnal atural Scence Fundatn f Chna ( ) & atural Scence Fundatn f Jangsu Prvnce f Chna(BK99),ths wrk was appled fr a Chna nventn patent(patent number ) - - 转载

2 hgh-frequency rpple current,then utput cyclcnverter wll demdulate hgh-frequency rpple current nt lw-frequency ac vltage. f energy s fed back t surce frm lad, utput cyclcnverter wll mdulate lw-frequency ac vltage nt hgh-frequency rpple current, then nput cyclcnverter wll demdulate hgh-frequency rpple current nt lw-frequency ac vltage. (a) crcut structure (b) sngle fur-quadrant pwer swtch mde crcut tplgy The pen lp system f ths knd f cnverter n DCM mde has nly a ple n the left plane, but the pen lp system f ths knd f cnverter has tw symmetrcal ples n the left plane and ne zer n the rght plane. Cmpared t the CCM mde, the DCM mde wes the advantages such as frst-rder system wthut zer and ple n the rght plane, frst-rder cmpensatng RC netwrk, and the current surce steady utput characterstcs [,6]. The transent vltage feedback cntrl strategy s ntrduced n the current mde AC/AC cnverters wth hgh frequency ac lnk, and the cntrl prncple s shwn n fg. when the parallel equvalent mpedance f flterng capactance C f and lad Z s nductve. The utput vltage u s cmpared wth a reference snusdal vltage u r,. the errr vltage ue s cmpared wth trangle wave u T, and utput sgnal u hf, u hf f tw cmparatrs and synchrnzatn sgnal usy are sent t drvers t drve pwer swtches S (S ), S (S ), S 3 and S 4. The synchrnzatn sgnal u sy and ts nvertng sgnal are sent t drvers t drve auxlary swtches S a (S a ) and S a (S a ).The utput vltage s synchrnzed wth bth the nput vltage and the reference vltage, therefre the reference vltage shuld synchrnze wth the nput vltage. The peratn mdes sequence f the cnverter s A-B-C-D, whereas the sequence f peratn mdes s D-C-B-A when the parallel equvalent mpedance f flterng capactance C f and lad Z s capactve. (c)push-pull mde crcut tplgy (a)the blck dagram (d)half-brdge mde crcut tplgy (e)full-brdge mde crcut tplgy Fg. The crcut structure and crcut tplges famly B Cntrl Strategy Accrdng t cntnuty f nductance current, ths knd f cnverter can be classfed nt three mdes: cntnuus current mde (CCM), crtcal cntnuus current mde and dscntnuus current mde(dcm). - -

3 A Fur Operatnal Mdes Accrdng t the drectn f utput vltage u and the fundamental wave cmpnent f secndary nductance current, the prpsed cnverter has fur peratn mdes A, B, C and D. Each mde s a Flyback cnverter. Take sngle fur-quadrant pwer swtch mde AC/AC cnverter as an example. f u >0 and >0 the prpsed cnverter perates n mde A, as shwn n Fg.3(a). u,,, S, D 4, C f and R make up f a Flyback cnverter, where S swtches n hgh frequency, S & S 3 are n and S 4 s ff. The pwer flw s frm the surce t the lad. f u <0 and >0 the prpsed cnverter perates n mde B, as shwn n Fg.3(b). u,,, S 3,D,C f and R make up f a Flyback cnverter, where S3 swtches n hgh-frequency, S & S 4 are n and S s ff. The pwer flw s frm the lad t the surce. f u <0 and <0 the prpsed cnverter perates n mde C, as shwn n Fg.3(c). u,,, S,D 3,C f and R make up f a Flyback cnverter, where S swtches n hgh-frequency, S & S 4 are n and S 3 s ff. The pwer flw s frm the surce t the lad. f u >0 and <0 the prpsed cnverter perates n mde D, as shwn n Fg.3(d). u,,, S 4,D,C f and R make up f a Flyback cnverter, where S 4 swtches n hghfrequency, S and S 3 are n and S s ff. The pwer flw s frm the lad t the surce. (b)the key cntrl sgnals Fg. The cntrl prncple f the current mde AC/AC cnverter wth hgh frequency ac lnk under nductve equvalent mpedance Ⅲ.OPERATOA MODES, STEADY PRCPES AD OTPT CHARACTERSTC Fg.3 Fur peratnal mdes f the current mde ac/ac cnverter wth hgh frequency ac lnk B Steady Prncples n rder t btan the steady prncples and utput characterstc, the fllwng assumptns are made:) takng mde A as an example;) the swtchng frequency f s s mre than the frequency f utput vltage & the nput vltage and the cut-ff frequency f the utput flter;3) the leakage nductr s mtted;4)ccm peratnal mde;5) r ncludes the transfrmer prmary wndng s resstance and the n-state resstance f S &S,. r ncludes the transfrmer secndary wndng s resstance and the n-state resstance f S 3 & D 4.The swtchng state equvalent crcuts durng ne swtchng perd are shwn n Fg.4. (a) the equvalent crcut n peratnal mde A (b) durng S n - 3 -

4 (c) durng S ff Fg.4 The swtchng state equvalent crcuts f the cnverter n mde A and CCM mde The nput vltage u and the utput vltage u can be cnsdered cnstant wthn ne swtchng perd, and the state-space averagng methd can be used t present the equatns f, u and u. The state equatn f the equvalent crcut shwn n fg.4(b) s gven by d -r +u (.a) dt du C u f - (.b) dt R The state equatn f the equvalent crcut shwn n fg.4(c) s gven by d (u + r ) (.a) dt - du C u f - (.b) dt R By averagng () and (), lettng d /dt0, du /dt0,, r r /( / ) R O / O, the steady state values f state varables durng ne swtchng perd are gven by D / (3.a) r r D( / ) D + + R ( D )R D / r D + ( D )R D / D ( r D ) (3.b) (3.c) D( / ) (4) R( D ) + r C Steady Output Characterstcs f The Cnverters deal state(r r 0) Accrdng t (3), the deal steady utput characterstc f the cnverters n CCM mde s gven by D (5) ( D ) n crtcal CCM mde p (6) ( D ) Ts where p s the peak value f the secndary nductance current. The lad current s gven by Ts G mn p D(-D) (7) Accrdng t.(7), the maxmum value f G fr D/ s Ts Gmax (8) 8 Cmbng (7) and (8), the deal steady utput characterstc f the cnverters n crtcal CCM mde must be satsfed G 4 Gmax D(-D) (9) n DCM mde p (0.a) DTs p (0.b) Δt where p s the peak value f prmary nductance current. Accrdng t.(0),the lad current has t satsfy Δt p TsD 4 Gmax D () Ts Therefre, the deal steady utput characterstc f the cnverters n DCM mde s btaned 4D G max () Real state(r,r 0) Accrdng t.(3),(5),(9) and (),the nrmalzed utput characterstc /( )f( / max ) s shwn n fg.5. The curve A whch s the utput characterstc n crtcal CCM mde s determned by (9); the curves n the rght f curve A are the utput characterstc n CCM mde, the stld lnes whch are deal vltage surce utput characterstc are determned by (5),and the dashed lnes whch are real vltage surce utput characterstc are determned by (3); the curves n the left f curve A are the apprxmate current surce utput characterstc n DCM mde are determned by (). Fg.5 rmalzed utput characterstcs f the current mde ac/ac cnverter wth hgh frequency ac lnk - 4 -

5 Fg.6 The utput characterstcs f the cnverterrelatn t nternal resstance durng CCM mde Accrdng t.(3), when the utput vltage s maxmum, D has t satsfy the cndtn D + r + / R ( r / R ) r / R (3) Wth the ncrease f D, the nnlnear nternal resstance r ncreases, and the utput characterstcs f the cnverter are apprxmate current surce prperty as shwn n fg.6. Even f the cnverter s n shrt-crcut (D0,D), the utput current cannt be nfnte. D.Desgn f Sngle Fur-Quadrant Pwer Swtch Mde AC/AC Cnverter n rder t guarantee peratng n DCM mde r crtcal CCM mde under maxmum utput pwer, the strage nductance shuld be satsfed D u Ts R mnd u Ts η η P max u R mn D [ sn( ωt )] Ts R mnd Ts η η (4) [ sn( ωt )] where η s the cnversn effcency, and R mn s the mnmal lad resstance. The turns rat f the strage energy transfrmer s gven by ( D )u Du ( D D ) sn( ωt ) sn( ωt ) ( D ) D (5) The peak current stress and vltage stress f pwer swtch S,S s respectvely DTs p p (6.a) DS DS + / (6.b) The peak current stress and vltage stress f pwer swtch S 3,S 4 s respectvely DTs p3p4 (7.a) DS3 DS4 + / (7.b) The utput flterng capactance s gven by [,6] 5Ts C f (8) 8kR mn where k s rpple vltage factr. E. Test Results The desgned prttype: Sngle fur-quadrant pwer swtch mde AC/AC crcut tplgy, transent vltage feedback cntrl strategy, DCM mde. rmalzed capacty S500VA, nput vltage u 0V ± 0%(50Hz), utput vltage u 0V(50Hz), pwer factr f lad csф ~+0.75, swtchng frequency f s 50kHz, maxmum duty cycle D max 0.5, sft ferrtes cre RKBD PM50*39 fr strage transfrmer( / 0uH/0uH), utput flterng capactance C f 0uF, sft ferrtes cre RKBD G fr nput flterng nductance(0uh), nput flterng capactance C50uF, MOSFET devce XFH580 (5A/800V) fr pwer swtches S ~S 4. The test wavefrms are respectvely shwn n fg.7. The test results demnstrate that the cnverter has fur peratn mdes(a,b,c,d);the swtchng frequency f the transfrmer s 50kHz ;the cnverter has the advantages such as utput snusdal vltage and the nput snusdal current wth lw THD, strng lad adaptng ablty and excellent regulated vltage perfrmance. The theretcal analyss s verfed by the test results. CH errr vltage u e 5V/dv CH utput vltage u 00V/dv Tme:.5ms/dv CH u gs 0V/dv CH u ds 50V/dv Tme:.5ms/dv CH nput vltage u 50V/dv CH utput vltage u 50V/dv Tme:.5ms/dv (a) nput vltage u 0V full resstve lad CH errr vltage u e 5V/dv CH utput vltage u 00V/dv Tme:.5ms/dv - 5 -

6 CH u gs 0V/dv CH u ds 50V/dv Tme:.5ms/dv CH nput vltage u 50V/dv CH utput vltage u 50V/dv Tme:.5ms/dv (b) nput vltage u 00V full capactve lad CH ugs 0V/dv CH uds 50V/dv Tme:.5ms/dv CH errr vltage ue 5V/dv CH utput vltage u00v/dv Tme:.5ms/dv CH u gs 0V/dv CH u ds 50V/dv Tme:.5ms/dv CH nput vltage u 50V/dv CH utput vltage u 50V/dv Tme:.5ms/dv (c) nput vltage u 4V full nductve lad CH errr vltage u e 5V/dv CH utput vltage u 00V/dv Tme:.5ms/dv CH nput vltage u 50V/dv CH utput vltage u 50V/dv Tme:.5ms/dv (d) nput vltage u 0V n lad Fg.7 The test wavefrms f the current mde ac/ac cnverter wth hgh frequency ac lnk F.COCSOS ()The prpsed cnverter whch can transfer ne unregulated snusdal vltage wth hgh THD nt anther regulated cnstant frequency snusdal vltage wth lw THD, s cnsttuted f nput cyclcnverter, hgh frequency strage transfrmer and utput cyclcnverter. The prpsed cnverter wes such advantages lke smple tplgy, twstage pwer cnversns, b-drectnal pwer flw, hgh frequency electrcal slatn, gd lad adaptng ablty and gd lne current wavefrm. () The prpsed crcut tplges famly nclude sngle fur-quadrant pwer swtch mde,push-pull mde,half-brdge mde,and full-brdge mde crcut. The sngle fur-quadrant pwer swtch mde and push-pull mde cnverter are sut fr lw nput vltage felds,but the half-brdge mde and fullbrdge mde cnverter are sut fr hgh nput vltage felds. (3) The prpsed cnverter based n Flyback cnverter has fur peratnal mdes and each mde s a Flyback cnverter. (4) The utput characterstcs and ts relatn t nternal resstance are gven. (5) The desgn crterns fr the key crcut parameters such as strage nductance, turn rat f the transfrmer, stress f pwer swtch, and utput flterng capactance are gven. (6)The crrectn and the advance f the prpsed cnverter s verfed by the test results. REFERECES [] Dalan Chen et al, vel statc nverters wth hgh frequency pulse DC lnk, EEE Tran. n PE,004,Vl.9,.4,pp.97~978. [] B.R. Pelley, Thyrstr Phase-Cntrlled Cnverters and Cyclcnverters, ew Yrk:Wlley,97. [3] eft C,et al, Thery and desgn f a 30-hp matrx cnverter,eee - 6 -

7 Tran. n A,99,Vl.8,.3,pp.546~55. [4] Dalan Chen et al, B-plarty Phase-shfted cntrlled vltage mde AC/AC cnverters wth hgh frequency ac lnk,eee PESC 03,003,pp.677~68. [5] Chen Dalan et al, Research n the un-plarty phase-shfted cntrlled vltage mde AC/AC cnverters wth hgh frequency ac lnk,prceedngs f the CSEE,003,vl.3,.,pp.9~3. [6] Mncha Huang et al, vel current mde b-drectnal hgh frequency lnk DC/AC cnverter fr PS,EEE PESC 98,998,pp.867~