Coupled Dual Interleaved Flyback Converter for High Input Voltage Application

Transcription

1 Culed Dual Interleaved Flyback Cnverter fr High Inut ltage Alicat Tg Qian, Brad Lehman rtheatern Univerity Det. Electrical & Cmuter Engeerg Btn, MA, 5, USA Abtract - Thi aer re an tegrated magnetic DC-DC cnverter uitable fr high ut vltage alicat. The cnverter i baed n a culed ut-erie and utut-arallel dual terleaved Flyback cnverter cncet. All the center and uter leg are gaed, and the tranfrmer are tegrated t ne magnetic cre with nt tight culg. The ga i beneficial fr ureg current ike caued by the vltage mimatch between the wdg. The tw tranfrmer are verely culed, and current rile reduct can be achieved with uitable culg deign. A rttye with ut and 4/4A utut i built. Exerimental reult verify the erfrmance f the new tlgy. I. ITRODUCTIO There i an creag demand mdern wer electrnic fr high denity wer cnverter. In mt cae, the ize f the magnetic cmnent, cludg tranfrmer and ductr, ignificantly fluence the verall rfile f the cnverter. Integrated magnetic technique [-] eem t be uitable lut fr high denity alicat. The attract i that tranfrmer and ductr are cmbed a gle cre, and therefre, ct and ize f the cnverter may be reduced. Generally, there are tw dmant tye f ilated tlgie ug tegrated magnetic: buck mde tlgie, uch a Frward [,], Puh-Pull [3,4], Half-Bridge [5,6] and Full-Bridge [5,6], and buck-bt mde tlgie, uch a dual Flyback [9,]. Mre recently, there are newly red tegrated bt cnverter [7] that are begng t ee alicat autmtive wer electrnic. Fr large te-dwn wer cnver, uch a 48 t, buck mde ilated tlgie have becme ular lut. A a reult, tegrated magnetic technique [-6] have been widely develed fr buck mde tlgie. Hitrically, magnetic tegrat i utilized fr Frward cnverter [,]. Hwever, recent reearch ay mre attent t full wave tegrated magnetic DC/DC cnverter [3-6], which clude Puh-Pull, Half-Bridge and Full-Bridge, etc. Fr examle, magnetic tegrat i utilized fr Puh-Pull Frward circuit with culed-ductr current dubler circuit [3,4]. A gle EI r EE cre i ued fr all the magnetic cmnent, cludg the ut ductr, the te-dwn tranfrmer and the utut filterg ductr. A well a reducg the verall ize f the cnverter, culed utut ductr greatly reduce the current rile, and thu imrve the wer efficiency. Incrratg an deendent ductr wdg t the tranfrmer i anther examle fr full wave tegrated magnetic tlgie [5,6]. The rigal full wave buck mde circuit erat i retaed fr thi arach. A flexible utut ductr wdg i added the center leg t timize the deign f utut ductr. Thi reearch maly fcue n the dicu f tegrated magnetic technique related with buck-bt mde ilated tlgie. In thi defit, an tegrated magnetic buckbt mde tlgy mean duble r multile Flyback circuit ug a gle magnetic cre, ce a gle Flyback utilize nly ne gaed magnetic cre t tre the energy the wer tranfrmer. A Flyback cnverter i a ular chice fr lw wer alicat, due t it imlicity and lw ct []. Fr examle, it i uitable fr ue a tw-tage AC/DC cnverter at a wer level f 5Watt r le. Fig. hw a tradital full wave buck-bt (Flyback wer cnverter [9,] that utilize ne magnetic cre t tegrate tw Flyback tranfrmer. In thi cae, the tw tranfrmer are culed with a lw reluctance the uter leg f the magnetic cre. The relatively higher reluctance magnetic rerty f the ductr L i tegrated t the magnetic tructure center leg. The tranfrmer tre the energy when S r S i turned n, and releae the energy t the lad when bth S and S are turned ff. Ideally, D and D cnduct imultaneuly t deliver the energy t the lad that the tw ductr are culed t reduce the current rile. C S S D D C r ut Fig. Tradital full wave buck-bt wer cnverter [9,] Thi aer re a new tegrated magnetic dual Flyback cnverter that i mre uitable fr high ut vltage /7/$. 7 IEEE 93

2 alicat. Secifically, tw terleaved Flyback cnverter are cnnected erie n the rimary ide and arallel n the ecndary ide. Due t terleaved erat f the Flyback circuit, the current rile i, thu, reduced a tyical terleaved Flyback circuit []. All the center and uter leg are gaed the new cnverter, and the tranfrmer are tegrated t ne magnetic cre with nt tight culg. Thi i beneficial fr ureg current ike caued by the vltage mimatch between the wdg. The tw tranfrmer are verely culed that ignificant current rile reduct can till be fulfilled withut tight culg. The detail f current rile reduct are exlaed Sect III. The fllwg feature are reented. Cnnectg the rimary ide erie reduce the vltage tree f the rimary cmnent. The rimary witche are rated at half f the crrendg vltage value a gle Flyback r a tradital full wave buck-bt wer cnverter [9,]. The n-reitance and ct f the rimary witche are, thu, ignificantly reduced. Interleaved erat with aralleled cnnect n the ecndary ide kee the benefit f rile reduct a a tradital full wave buck-bt wer cnverter [9,] de. T atify a certa current rile requirement, magnetizg ductance can be reduced by mean f uitable ductr culg deign. Due t the mutual fluence f the tw culed ductr that i cmbed with the tranfrmer, further current rile reduct can be achieved when cmared with terleaved Flyback cnverter withut culg. Current ike caued by the vltage mimatch between the wdg can be ureed by gag all the center and uter leg. Cmared with tight culg, uch a the cndit a tradital full wave buck-bt wer cnverter hwn Fig., gag all the leg weaken the culg between the tw Flyback wdg, and thu, reduce the effect f the vltage mimatch. exceed 5%. It huld be emhaized that weakened culg de nt necearily acrifice rile cancellat thi cae. Detailed rile calculat i available Sect III. Hwever, ynchrnized erat with uitable culg deign i beneficial fr rile reduct. Thi aer maly analyze the terleaved cndit when duty rati i le than 5% a hwn Fig.3. S and S are the ma rimary witche. T and are the vltage acr the rimary wdg a T hwn Fig.. i and i are the current thrugh the rimary wdg. i and i are the current thrugh the ecndary wdg. An E magnetic cre i ued thi aer. Each tranfrmer utilize ne uter leg fr wdg. The fllwg decrit exla the detailed rcile f the red tlgy. t t i defed a ne duty cycle T. The length f 4 t t and t t are defed a DT, which rereent the 3 duty rati. Aume and are the turn f the rimary and ecndary wdg. The ut t utut tranfer rati i D /[ ( D ] ( C C S S T T I I Fig. Pred dual culed Flyback cnverter GS GS T I I D D C r ut II. OPERATIO PRICIPLE Figure hw the red culed ut-erie and ututarallel dual terleaved Flyback cnverter, and Fig.3 rereent the related wavefrm. The rimary witche are rated at half f the crrendg vltage value a gle Flyback r a tradital full wave buck-bt wer cnverter [9,] due t erie cnnect f the tw Flyback. Al, ga fillg i ued fr all the three leg. A hwn Fig., the uer Flyback (Flyback cnit f C, S, D, C and tw wdg ne uter leg. The lwer Flyback (Flyback cnit f C, S, D, C and tw wdg the ther uter leg. Sce gag all the three leg weaken the culg, the tw Flyback can actually erate deendently (if deired. The current rgg caued by the vltage mimatch between the tw Flyback wdg can be ignificantly ureed due t the weakened culg. Therefre, the duty rati can T I I I I t t t t3 t4 Fig.3 Timg and wavefrm f the red circuit teady tate Interval ( t t : The cndit f thi erid i hwn Fig.4 (a. Durg thi terval, S i turned n. The vltage acr the rimary wdg f the uer Flyback i equal t /. The uer Flyback circuit deliver energy frm c 94

3 C t the tranfrmer n the rimary ide. The rimary current i, which i hwn Fig., creae learly. The ecndary dide D i revere-biaed. At the ame time, S i ff. The ecndary ide current f the lwer Flyback, which i i, flw thrugh D and charge C. The current value beg t decreae. In thi cae, the utut vltage i alied t the ecndary wdg f the lwer Flyback. C C S S (a Interval ( t t D D C r ut Interval 3 ( t t : The cndit f thi terval, which i 3 hwn Fig.4 (c, i imilar a terval. The tw Flyback circuit witch the cndit. S i turned n. The vltage acr the rimary wdg f the uer Flyback i equal t c /. The lwer Flyback circuit deliver energy frm C t the tranfrmer n the rimary ide. The rimary current i, which i hwn Fig., creae learly. At the ame time, S rema ff. The ecndary ide current f the uer Flyback, which i i, flw thrugh D and charge current value beg t decreae. The utut vltage alied t the ecndary wdg f the uer Flyback. C. The i Interval 4 ( t3 t : Fig.4 (d hw the cndit f the lat 4 terval. Thi cae i the ame a terval. Bth Flyback circuit releae energy n the ecndary ide. The utut vltage i alied t the tw ecndary wdg. C C C S S S (b Interval ( t t D D D C C r ut r ut III. RIPPLE CALCULATIO FOR COUPLED CODITIO Fr tw culed ductr, the fllwg tyical relat can be btaed [3,8], di di v L M ( di di v L M (3 In the abve cae, let M M, and v and v are the L L vltage alied n the tw crrendg wdg. M i the culg ductance. C C C S S S (c Interval 3 ( t t 3 D D D C r ut Fr thi red culed Flyback, the fllwg equat abut the current rile can be achieved baed n tyical equat and ecific cndit. Ug the derived equat, timized deign can be achieved fr cnverter accrdg t their ecific requirement. When all the leg have ga with arximately ame ditance, i arximately equal t / 3. Aume M i the culg ductance between the tw rimary wdg. L and L are the magnetizg ductance f the rimary and ecndary wdg. and are the ut and utut vltage. Fr each Flyback, / i alied. (d Interval 4 ( t3 t 4 Fig.4 Detailed decrit f the erat rcile f the red circuit Interval ( t t : A hwn Fig.4 (b, S i turned ff durg thi terval. Bth Flyback circuit tart t releae the tred energy frm the tranfrmer t the utut caacitr and lad. Therefre, current i ge thrugh dide D and i ge thrugh dide D. The vltage acr each ecndary wdg i equal t. Interval ( t t : Durg thi terval, current circulate thrugh the rimary wdg f Flyback and the ecndary wdg f Flyback. Thee tw wdg are cnidered a tw culed ductr. Sce / i alied t the rimary wdg f Flyback, and i alied t the ecndary wdg f Flyback, the fllwg frmula related with current rile are btaed accrdg t equat ( and (3. di / ( / L, 95

4 di L ( / Sce i, we al have / C d a dicharge tate. becaue ( / i itive. / (4 i. The caacitr i rut i i creag arximately learly Interval ( t t : Durg thi terval, current circulate thrugh the ecndary wdg f bth Flyback circuit. Thee tw wdg are cnidered a tw culed ductr. Sce i alied t the ecndary wdg f each Flyback, the fllwg frmula related with current rile can be achieved accrdg t equat ( and (3. di di L L (5 Al, d C i i. The caacitr i a charge tate rut ce i i. The tw culed ecndary ductr are rut bth releag their energy t the lad. Interval 3 ( t t : Durg thi terval, current circulate 3 thrugh the ecnd wdg f Flyback and the rimary wdg f Flyback. Thee tw wdg are cnidered a tw culed ductr. Sce i alied t the ecndary wdg f Flyback, and / i alied t the rimary wdg f Flyback, the fllwg frmula related with current rile are btaed. di ( / / L, di / ( / L (6 Sce i, we al have d C i. Similar t rut Interval, the caacitr i a dicharge tate and i i creag arximately learly. Interval 4 ( t3 t : Durg thi terval, current circulate 4 thrugh the ecndary wdg f bth Flyback circuit. Thee tw wdg are cnidered a tw culed ductr. Sce i alied t the ecndary wdg f each Flyback, the fllwg frmula related with current rile are btaed. di di L L (7 Similar t Interval II, d C i i. The caacitr i rut a charge tate. The tw culed ecndary ductr are bth releag their energy t the lad. Further Dicu n the Pred Circuit A hwn Fig.3, the current rile i determed by / ( / i i D ( L f When cmared with n culg cndit (Sue ug ame ductance value L, and the current rile i determed by D i., / ( / / L f huld be atified rder t achieve a reduced current rile. In ther wrd, maller ductr can be ued t atify identical current rile requirement when. Secifically, the fllwg difference are remarked when cmared with a tradital cnverter [5,6] Fig... The new arach cnnect the ut f the tw Flyback erie, while the tradital methd cnnect the ut arallel.. The red cnverter ha 3 ga all leg. The tradital cnverter nly ha ga the center leg. 3. The ecndary wdg are verely culed the new cnverter, and directly culed the tradital cnverter. Frm the firt difference, it can be cncluded that the red methd ha half f the vltage tre when cmared with the tradital methd. Due t ut-erie and utut-arallel cnnect, DUal Magnetic art with Balanced Oerat can be fulfilled the red circuit. Accrdg t the ecnd and third difference, the ecndary wdg f the tradital cnverter are directly culed with tight culg. Hwever, fr ractical circuit, eecially fr thi high vltage alicat, witche cannt erate exactly imultaneuly. Mr mimatch can lead t high current ike and renance when the tw wdg have gd culg and mall leakage ductance. On the ther hand, the ecndary wdg f the new cnverter are verely culed with nt tight culg ce all three leg are gaed. Current ike and renance due t vltage mimatch can be ureed ce the leakage ductance ha a big value. Al, current rile reduct can till be achieved with uitable culg deign, and the weakened culg between the tw tranfrmer allw the duty rati t be greater than 5% the re circuit. I. EXPERIMETAL RESULTS T verify the rcile f the red cheme, a rttye with ut and 4/4A utut i built by ug (8 96

5 the red tlgy witched at khz hard witched. FDD65TF (5, 6A, DPAK i ued fr the rimary witche. (It huld be remarked that MOSFET rated at 8- are needed thi ecificat fr a gle Flyback r a full wave Flyback [5,6] hwn Fig.. Secndary dide ( D and D ue CWQF (, A, DPAK. The tw culed tranfrmer are tegrated t ne E magnetic cre. The cr ectal area f the magnetic cre i 78.5mm. The ga are the ame each leg. Therefre, i arximately equal t / 3. Each tranfrmer ha 6 turn fr the rimary wdg and 3 turn fr the ecndary wdg. wavefrm frm the uer and lwer Flyback circuit, it can be clearly een that the tw art are elf-balanced. Each art hare half f the ut vltage. a Secndary current f the uer Flyback i hwn (a Primary current f the uer Flyback i hwn ( (b Secndary current f the lwer Flyback i hwn Fig.6 (Channel, 5/div, d (Channel, 5/div, ecndary d current (Channel 3, 5A/div and vltage acr the ecndary dide (Channel 4, 5/div Efficiency curve (b Primary current f the lwer Flyback i hwn Fig.5 (Channel, 5/div, d (Channel, 5/div, rimary d current (Channel 3, A/div and vltage acr the ecndary dide (Channel 4, 5/div Fig.5 hw the wavefrm f (Channel, 5/div, d d (Channel, 5/div, rimary current (Channel 3, 5A/div and vltage acr the ecndary dide (Channel 4, 5/div when the ut vltage i 4. Fig.6 hw the wavefrm f (Channel, 5/div, d d (Channel, 5/div, ecndary current (Channel 3, 5A/div and vltage acr the ecndary dide (Channel 4, 5/div when the ut vltage i 4. The tw Flyback circuit are terleaved. The wavefrm f the ecndary ide are hae with the rimary ide. The change rate f the ecndary current f ne Flyback differ a exected when the ther Flyback erate at different mde. Thi henmenn ccur due t the mutual effect between the culed wdg. By cmarg the Efficiency (% Inut vltage ( Fig.7 Efficiency f the built rttye By alyg the red culed ut-erie and ututarallel dual terleaved Flyback cnverter, an efficiency f 89.% at 4 ut and 4/4A utut i btaed. Fig.7 hw the efficiency curve durg the whle ut vltage variat range. The exerimental reult verify the rcile and erfrmance f the cheme. 97

6 . COCLUSIO A culed ut-erie and utut-arallel dual terleaved Flyback cnverter fr high ut vltage alicat i red. Cnnectg the rimary ide erie reduce the vltage tree f the rimary cmnent. All the center and uter leg are gaed, and the tranfrmer are tegrated t ne magnetic cre with nt tight culg. The current rgg caued by the vltage mimatch between the tw Flyback wdg can be ureed due t the weakened culg. The tw tranfrmer are verely culed that ignificant current rile reduct can till be fulfilled with nt tight culg. Exerimental reult verify the erfrmance f the new tlgy. REFERECES [] E. Blm, ew tegrated-magnetic dc-dc wer cnverter circuit & ytem, Prc. IEEE APEC 987, [] R. Severn and E. Blm, Mdern DC/DC Switchmde Pwer CnverterCircuit. ew Yrk: an trand Rehld Cmany, Dec. 985 [3] Peng Xu; Ma Ye; Lee, F.C.; Sgle magnetic uh-ull frward cnverter featurg built- ut filter and culed-ductr current dubler fr 48 RM, Alied Pwer Electrnic Cnference and Exit,, vl., [4] Xu, P.; Lee, F.C.; Deign f high-ut vltage regulatr mdule with a nvel tegrated magnetic, Alied Pwer Electrnic Cnference and Exit,, vl.,.6-67 [5] Liang Yan; Lehman, B.; Integrated magnetic full wave cnverter with flexible utut ductr, IEEE Tranact n Pwer Electrnic, Iue, March 3, vl.8, [6] Jian Sun; Webb, K.F.; Mehrtra,.; Integrated magnetic fr currentdubler rectifier, IEEE Tranact n Pwer Electrnic, Iue 3, May 4, vl.9, [7] Liang Yan; Lehman, B.; An tegrated magnetic ilated tw-ductr bt cnverter: analyi, deign and exerimentat, IEEE Tranact n Pwer Electrnic, Iue, Mar 5, vl., [8] Pit-Leng Wng; Peng Xu; Yang, P.; Lee, F.C.; Perfrmance imrvement f terleavg RM with culg ductr, IEEE Tranact n Pwer Electrnic, Iue 4, July, vl.6, [9] Fred O.Barthld; Full Wave Buck-Bt Pwer Cnverter with Buck Pwer Cnverter Prertie, United State Patent, Patent number: , July 5, 995 [] G. Q. Mrri, Magnetically tegrated full wave dc t dc cnverter, U.S. Patent , Set., 996 [] Chung, H.S.-H.; Hui, S.Y.R.; Wei-Hua Wang; A zer-current-witchg PWM flyback cnverter with a imle auxiliary witch, IEEE Tranact n Pwer Electrnic, Iue, March 999, vl.4, [] H. Mart, tlgy fr miature wer uly with lw vltage and lw rile requirement, United State Patent, Patent number: