A Novel High Frequency Isolated Full-Bridge Three-Level AC/AC Converter

Transcription

1 Jurnal f Indusral and Inellgen Infrman Vl. 3,., March 05 A vel Hgh Frequency Islaed Full-Brdge hree-level AC/AC Cnverer Zeyu Xang and Le L Cllege f Auman, anjng Unversy f Scence and echnlgy, anjng, Chna E-mal zeyuxangnjus@63.cm, llenjus@mal.njus.edu.cn he crcu plgy f he hgh-frequency slaed full-brdge hree-level AC/AC cnverer s shwn n Fg.. he crcu plgy s made up f npu alernang vlage surce, npu fler nducance, dvder capacance, hree-level cycle-nverer, hgh frequency ransfrmer, upu cycle-nverer, upu fler and upu alernang lad, whch can urn he unsable alernang curren n he snusdal sable alernang curren wh same frequency. hs hree-level cyclenverer s cmpsed f ne r mre w-way cnrl mdules, whch can change he npu vlage n hree upu levels. he basc cnsuen un ncludes a furquadran pwer swch and a fur-quadran clamp pwer swch, each pwer ube s paralleled wh he crrespndng parasc dde. Basc cmpnen n seres wh each her un can reduce he vlage sress. w capacrs are used as he clampng vlage surces. Fve knds f level, whch are, /, 0, -/, -, can be g a he bh sdes f he ransfrmer and hree knds f level, whch are, /, 0, can be g a he frn-end f fler. Absrac In rder slve he prblems exsed n he feld f hgh pwer applcans such as vlage sresses and harmnc nerferences f he w-level AC/AC cnverer. A new knd f hgh frequency slaed full-brdge hree-level AC/AC drec cnverer s prpsed. he cnverer has many advanages such as w-sage pwer cnversns, smple plgy and, lw vlage sresses. he plgy f crcu, peranal prncple and sx knds f peranal sraegy are deeply analyzed. he cnrl mehd f SPWM, whch s based n nsananeus vlage value feedback, s used respnd fas he change f npu and upu vlage. he cnrl mehd f cnverer drvng sgnal, whch s frm he cmparng f fur carrer waves and errr magnfcan sgnal, s summarzed. he crcu s smulaed by saber and he resul ndcaes ha he wave f he cnverer s mprved; hwever he harmnc and vlage sresses are reduced. Index erms hgh frequency lnk, hree-level, AC/AC, SER IRODUCIO Mul-level pwer cnversn s a new echnlgy whch can mee hgh vlage and pwer. Devces f lw grade can cnver hgh pwer whch wdens he range fr pwer and elecrnc echnlgy use n he feld f hgh pwer and vlage []. Suppred by he fas develpmen f hgh-pwer sem-cnducrs ver recen years, mullevel cnverers have emerged and enable beer lne-sde behavr han curren cnverer plges[]-[4]. AC/AC cnverer s pwer semcnducr devce whch can cnver a ceran frequency and amplude f AC n he same r anher frequency and amplude f AC. AC/AC cnverer wh mul-level can wden he usage n hgh vlage and pwer and mprve he qualy f wavefrm. [5] In hs paper, radnal full-brdge w-level AC / AC cnverer has been mprved. A new knd f hghfrequency slaed full-brdge hree-level AC /AC cnverer s prpsed, whch can prduce beer wave f hree-level vlage a frn-end f upu fler. he pwer cnverer vlage sresses are reduced s ha can be used n he feld f hgh pwer and vlage applcans. II. a b b b a b A B b b a a a Fgure. Islaed full-brdge hree-level AC/AC cnverer he uns f,,,,, S8 are fur-quadran pwer swches, s fur-quadran clampng pwer swches n Fg.. s he npu flerng nducance, s he upu flerng nducance, s he upu flerng capacr. Lw frequency alernang vlage can be urned n hgh frequency pulsan vlage by npu cyclenverer when pwer s ransmed lad frm elecrc fence. Hgh frequency pulsan curren can be demdulaed by upu cycle-nverer and lw frequency alernang vlage can be g hrugh upu fler. Oupu cycle-nverer wrks n he sae f mdulan and npu cycle-nverer wrks n he sae f demdulan when pwer s reversed elecrc fence frm lad. [6] CIRCUI OPOLOGY OF HE IVERER Manuscrp receved December 9, 03; revsed May 5, Engneerng and echnlgy Publshng d 0.70/j a a I. 9

2 Jurnal f Indusral and Inellgen Infrman Vl. 3,., March 05 III. SEADY-SAE AALYSIS AD EXERAL CHARACERISICS A. Operanal Mdal Analyss In rder smplfy he descrpn f he crcu peran, we make he assumpn () All cmpnens, ncludng swches, ddes, nducrs and capacrs are hugh be deal devces, and als nernal ressance f pwer surce s equal zer. () Selec he same specfcans f D~D7,,, =, =. a a a a b b a a b b a a b b (d) Swchng sae D a a b b b a b a a b a b (e) Swchng sae E / V -/ - / V Fgure. Drvng sgnal wavefrms f he pwer swches a a a b b a a b b a a b b (f) Swchng sae F Fgure 3. he swchng saes when U0>0, L f> 0 a a a a b a a b b b (a) Swchng sae A a a a a b b b b (b) Swchng sae B a a b b a a b b In a hgh-frequency swchng cycle, here are sx swch-mdes f he cnverer. use U0>0, L f>0 as an example fr analyss, he drvng sgnal wavefrms s shwn n Fg. 3. When n nrmal wrkng prcess, pwer swches wll be urned n r ff n he se rder, hus realzng he crculan wrkng mdes f A-B-A-C-D-E- D-F-A. Swch mde [ 0 ~ ] and [ ~ 3 ] Fg. 3(a). Swch S 4, S 5 and S 6 wll be urned n a he me f 0 r.hen, prmary curren crculaes hrugh C, S 5a, S 5b, S 4a, S 4b, whle he flerng nducance curren crculaes hrugh S 6a, S 6b. A hs mmen, he curren hrugh he secndary ransfrmer s ncreasng quckly. he vlage f he prmary wndng f he ransfrmer s U U / () a a b b a b a b he vlage n frn f he upu fler su U U U U () a a b (c) Swchng sae C a b Swch mde B [ ~ ] Fg. 3(b). Swch uns S s urned n a he me f, whle S 5 s urned ff and S 4, S 6 reman urned n. hen prmary 05 Engneerng and echnlgy Publshng 0

3 Jurnal f Indusral and Inellgen Infrman Vl. 3,., March 05 curren crculaes hrugh S a, S b, S 4a, S 4b, whle he flerng nducance curren crculaes hrugh S 6a, S 6b. A hs mmen, he curren hrugh he secndary ransfrmer cnnues ncrease. he vlage f he prmary wndng f he ransfrmer su U U (3) he vlage n frn f he upu fler su U U U U (4) Swch mde C [ 3 ~ 4 ] Fg. 3(c). Swch uns S 3, S 7 s urned n a he me f 3, whle S 5 s urned ff and S 4, S 6 reman urned n. hen prmary curren crculaes hrugh S 4a, S 4b, S 3a, S 3b, and acheve he psve maxmum. he flerng nducance curren crculaes hrugh S 6, S 7. Bu he curren hrugh S 6a, S 6b wll cnnue decrease unl zer whle curren flwng hrugh S 7a, S 7b wll cnnue ncrease, hus realzng he exchange beween he pwer swch uns S 6 and S 7. A hs me, he vlage f he prmary wndng f he ransfrmer s zer, he frn vlage f upu fler s als zer by calculan and verfcan, whch als avds he crculan phenmenn a he verlappng perd f he cyclcnverer. Swch mde D [ 4 ~ 5 ], [ 6 ~ 7 ] Fg. 3(d). Swch uns S, S 5 s urned n a he me f 4 r 6, whle S 3, S 6, S 4 s urned ff and S 7 reman urned n. U frm psve negave, hen, prmary curren crculaes hrugh S a, S b, S 5a, S 5b, C. A hs pn cmmuan has ended, whle he flerng nducance curren flws hrugh swch uns S 7a, S 7b a he same me. he curren flwng hrugh he secndary sde f he ransfrmer wll cnnue by negave grwh. he vlage f he prmary wndng f he ransfrmer su U / (5) he vlage n frn f he upu fler su U U U U (6) Swch mde E [ 5 ~ 6 ] Fg. 3(e). Swch uns S 3 s urned n a he me f 5, S, S 7 reman urned n. hen prmary curren crculaes hrugh S a, S b, S 3a, S 3b, whle he flerng nducance curren flws hrugh swch uns S 7a, S 7b. In hs case he ransfrmer prmary curren s negave and cnnues ncrease. he vlage f he prmary wndng f he ransfrmer su U U (7) he vlage n frn f he upu fler su U U U U (8) Swch mde F [ 7 ~ 8 ] Fg. 3(f). Swch uns S, S 6 s urned n a he me f 7, S, S 7 reman urned n. hen, prmary curren crculaes hrugh S a, S b, S a, S b, and acheve he maxmum negave psve, whle he flerng nducance curren flws hrugh swch uns S 6, S 7, Bu he curren ha crculaes hrugh S 7a, S 7b wll cnnue decrease unl zer, whle he curren ha crculaes hrugh S 6a, S 6b wll cnnue ncrease, hus realzng he exchange beween he pwer swch uns S 6 and S 7. A hs me, he vlage f he prmary wndng f he ransfrmer and he vlage n frn f he upu fler are zer. B. he Expressn f Oupu Vlage and Fler Inducr Curren Expressn Frm he abve analyss, when he cnverer s perang a seady sae and he upu nducr curren s n CCM mde, here are hree equvalen crcus n a swchng cycle, whch s shwn n Fg. 4. he parameer r s he equvalen ressance denng he wndng ressance f he ransfrmer, leakage reacance and parasc ressance f he fler. r (a) r U0 (c) r (b) Fgure 4. hree equvalen crcu n a swchng cycle U can be regarded as seady value as he swch frequency s much hgher han cu-ff frequency f vlage. he sae ransfrmer f equvalen crcu n Fg. 4(a) s d r u u (9) d C f du d U0 u (0) he sae ransfrmer f equvalen crcu n Fg. 4(b) s U0 05 Engneerng and echnlgy Publshng

4 Jurnal f Indusral and Inellgen Infrman Vl. 3,., March 05 d L r u u () f d C f du d u () he sae ransfrmer f equvalen crcu n Fg. 4(c) s d r u (3) d C f du d u (4) Eq. () and () mulpled by D plus (9), (0) mulpled by D plus (3), (4) mulpled by (-D -D ), d d, du / d 0, he seady-sae assumpn / 0 value f Sae varables s 0 u u ( D D ) R r ( ) R r u DD L L (5) (6) When n deal sae and CCM mde, he exernal characersc f ransfrmer s he lad curren I G s u u ( D D ) (7) 0 IG [ ( ) ( )] ( D D ) ( 3)( D D ) (8) Assumpn D 0., he lad curren I G U 4 ( ) (9) IG s D D When D 0.5, I ake he maxmum G I s Gmax u (0) 80 When n deal sae and CRM mde, he exernal characersc f ransfrmer s 80 4 IG IGmax ( D D ) () When n DCM mde, he upu lad curren I s 80 3 (0.DD 0.08) I IGmax (0.6D 3D 0.7D 0.6) D D When n deal sae and DCM mde, he exernal characersc f ransfrmer s 3 u 0.6D 3D 0.7D u (0.D D 0.08) I / 80I Gmax D D IV. COROL CIRCUI DESIGIG () (3) Feedback cnrl scheme f nsananeus vlage value s adped n he hgh-frequency slaed full-brdge hree-level AC/AC drec cnverer []. Cmparng he upu feedback vlage wh he reference vlage, he errr vlage U e s baned. hrugh he abslue value crcu we can ge U e. hen he fur sawh waves cmpare wh he vlage U e respecvely. he fur sawh waves s shwn n Fg. 5. Cmparsn wh sawh waves, he sgnal f SPWM, SPWM, SPWM3 SPWM4 are baned. he fur SPWM waves baned a seres f lgcal ransfrman can ge he drve sgnal pwer swch. uf ur PI Cmparar Uf Samplng sgnal Ur Reference sgnal u Swah surce ue u u u3 u4 Fgure 5. Cnrl prncple D flp-flp Lgcal ransfrman In rder cnrl he swch n and ff prduce a hree-level vlage sep wave, yu need maser pwer swch duy cycle s dvded n hree pars. Fur waves f SPWM can be g by cmparng sawh waves n Fg. 5 wh U e. I s shwn n Fg. 6. Frequency f sw and sw3 are same and hree mes larger han sw and sw4. Amplude f saw-h waves s mre han hree mes larger han he amplude f sne wave. sne sw sw sw3 sw4 Sawh wave Sawh wave3 Sawh wave Sawh wave4 Fgure 6. he fur sawh waves V. SIMULIK Hgh frequency slaed full-brdge hree-level AC/AC drec cnverer, ransen vlage feedback cnrl sraegy, CCM mde. rmalzed capacy S KVA, npu vlage U 0V 0%(50 Hz), pwer facr f he lad csl 0.75~ 0.75,swchng frequency 50KHz,urn ra f he ransfrmer fs npu flerng nducance 3 0H,npu capacance 30F, upu sne 05 Engneerng and echnlgy Publshng

5 Jurnal f Indusral and Inellgen Infrman Vl. 3,., March 05 flerng capacance nducance C f 8 F, upu Vlage and curren frm ressve lad are shwn n Fg. 7(a). Vlage and curren frm capacve lad are shwn n Fg. 7(b). Vlage and curren frm nducve lad are shwn n Fg. 7(c). Vlage wavefrm a bh sdes f ransfrmer and frn-end f fler are shwn n Fg. 8. he resul f smulan ndcaes ha wavefrm f vlage and curren frm full-brdge hree-level AC/AC cnverer s much beer wh less harmnc and rpples. he upu fler nducance and sze f he fler are much smaller. Man pwer swch ube vlage sresses are decreased by u/. flerng L f 650 H, raed ressve lad. ; RC seres capacve lad 9. C 0.4 F seres nducve lad 9. L 5.49mH. VI. COCLUSIO A new knd f hgh frequency slaed full-brdge hree-level AC/AC drec cnverer s prpsed. he plgy f crcu, peranal prncple and prcess, characersc f ransfrmer are deeply analyzed. Cnrl sraegy whch s based n vlage nsan value s desgned n. he smulan s based n SER and he resul prves () Hgh frequency elecrcal slan, w-sage pwer cnversn, bdrecn pwer flw are all advanages f he cnverer. hree-level wave can be g a he frn-end f fler. Swch ube vlage sresses can be reduced. Vlage harmnc can be decreased. I can be used n he feld f hgh pwer and vlage applcans. () Cmparng wh he radnal mullevel cnverer, hs cnverer has he advanage f smple srucure and hgh frequency elecrcal slan. (3) he ably f ransfrmer carry lad s srng. Oupu vlage wavefrms frm ressve lad, capacve lad and nducve lad are sable and qualy. (a) Ressve lad (b) Capacve lad REFERECES [] [] [3] (c) Inducve lad [4] Fgure 7. Oupu vlage uand lad curren [5] [6] Fgure 8. Lcal speradng fgures f 05 Engneerng and echnlgy Publshng W. Zheng, Research n he frward AC-AC mde hree-level AC/AC cnverer, Cllege f Auman Engneerng, anjng Unversy f Scence & echnlgy, 008. D.-C. ang and L. L, he mprved cmbnan mde hreelevel AC/AC cnverer, n Prc. IEEE Inernanal Pwer Elecrncs and Mn Cnrl Cnference, 009, pp J.-D. Yang and L. L, A buck-bs mde hree-level sngle-sae AC/AC cnverer, ransacns f Chna Elecrechncal Scey, vl. 5, n., pp. 07-3, Feb. 00. J. Rdrguez, J.-S. La, and F. Z. Peng, Mullevel nverers A survey f plges, cnrls, and applcans, IEEE rans. Ind. Elecrn., vl. 49, n. 4, pp , Aug. 00. M. Glnka, A new AC/AC mullevel cnverer famly, IEEE ransacns n Indusral Elecrncs, vl. 5, n. 3, pp , June 005. J. an, H.-J. ang, and P.-S. Ye, Mdelng and cnrl f AC Buck dynamc vlage regular, Elecrc Machnes and Cnrl, vl. 4, n. 8, pp. 0-06, Aug. 00. Zeyu Xang receved he B.S. degree frm he Deparmen f Elecrcal Engneerng Auman, anjng Unversy f Scence and echnlgy, anjng, Chna n 0. He s currenly wrkng wards he M.S. degree n pwer elecrncs and pwer ransmssn a cllage f Auman, anjng Unversy f Scence and echnlgy, anjng, Chna. Hs research neress nclude mullevel echnque and AC/AC cnverers. u and u 3

6 Jurnal f Indusral and Inellgen Infrman Vl. 3,., March 05 Le L (M 09) receved he B.S. degree frm he Deparmen f Elecrcal Engneerng, Shandng Unversy f Scence and echnlgy, Qngda, Chna, n 997, and he Ph.D. degree frm he Deparmen f Elecrcal Engneerng, anjng Unversy f Aernaucs and Asrnaucs, anjng, Chna, n 004. He s currenly an Asscae Prfessr wh he Cllege f Auman Engneerng, anjng Unversy f Scence and echnlgy, anjng. He has publshed mre han 50 echncal papers. Hs research neress nclude mullevel echnque, hgh-frequency pwer cnversn, and cnrl echnque. Dr. L was he recpen f ne frs class reward prducn f scence and echnlgy f Jangsu Prvnce and s he hlder f hree Chna paens. 05 Engneerng and echnlgy Publshng 4