Voltage Source Multi Switched Capacitor Boost and Buck-Boost High Gain DC-DC Converters

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1 olage ource Muli wiched Capacior Boos and Buck-Boos High ain DC-DC Converers Amir, A., Rahim,. A., Che, H.., & Elkhaeb, A. (17). olage ource Muli wiched Capacior Boos and Buck-Boos High ain DC-DC Converers. In Ausralasian Universiies Power Engineering Conference 17 (AUPEC 17): Proceedings IEEE. Published in: Ausralasian Universiies Power Engineering Conference 17 (AUPEC 17): Proceedings Documen ersion: Peer reviewed version Queen's Universiy Belfas - Research Poral: Link o publicaion record in Queen's Universiy Belfas Research Poral Publisher righs 17 IEEE. This work is made available online in accordance wih he publisher s policies. Please refer o any applicable erms of use of he publisher. eneral righs Copyrigh for he publicaions made accessible via he Queen's Universiy Belfas Research Poral is reained by he auhor(s) and / or oher copyrigh owners and i is a condiion of accessing hese publicaions ha users recognise and abide by he legal requiremens associaed wih hese righs. Take down policy The Research Poral is Queen's insiuional reposiory ha provides access o Queen's research oupu. Every effor has been made o ensure ha conen in he Research Poral does no infringe any person's righs, or applicable UK laws. If you discover conen in he Research Poral ha you believe breaches copyrigh or violaes any law, please conac openaccess@qub.ac.uk. Download dae:1. Apr. 19

2 olage ource Muli wiched Capacior Boos and Buck-Boos High ain DC-DC Converers Asim Amir 1, Aamir Amir 1, asrudin Abd Rahim 1, Hang eng Che 1, and Ahmad El Khaeb 1 Power Energy Dedicaed Advanced Cenre (UMPEDAC), Wisma R&D, Universiy of Malaya, 5999 Kuala Lumpur, Malaysia chool of Elecronics, Elecrical Engineering and Compuer cience, Queen's Universiy Belfas, BT9 5AH, Unied Kingdom Absrac This paper presens dc-dc converers based on muli swiched capacior cells for high boos. The essence in a grid conneced micro-inverer is dc-dc converer; i is employed o boos he low P volage, which varies from DC in order o increase he bus volage o be 38-4 DC. Inverer uilizes his high bus volage o mach he grid volage, which is 4 AC a 6 Hz frequency. For convenional boos converer, his requires high boos raio ha is beyond is pracical capabiliy. Furhermore, he high duy raio needed will resul in high componens sress ha suppresses he overall efficiency of he converer. To overcome aforemenioned problems, his paper suggess he inegraion of muliple swiched-capacior cells (Cs) wih convenional boos and buck-boos converers o achieve high dc-link volage. Resuls based on 1 W laboraory prooype are given o verify he heoreical analysis. Index Terms-- High volage gain, lower duy raio, muliple swiched capacior (C) cells, wide inpu volage variaion I. ITRODUCTIO Over he pas few decades, phoovolaic (P) and fuel cell echnologies have been gaining populariy among researchers as alernaives o fossil fuel based power generaion sysems [1-4]. The high sep-up Dc Dc converer is he essence in a phoovolaic (P) grid conneced micro inverer sysem; i is employed o boos he low P volage which is DC o a higher bus volage around 38-4 DC. The inverer uilizes his high bus volage o mach he grid volage which is 4 AC a 6 Hz frequency [1-7]. A simple soluion o his is o connec numerous P or fuel cell unis in series, unil he required bus volage level is obained. This issue has been addressed by auhors in [6, 7]. Isolaed Dc Dc converers can be uilized o sep up o he required volage, using high volage ransformer (HT). In such case, here are wo basic echniques o obain a high volage gain. Firs is by increasing he urns raio of he HT; and second is o use volage muliplier circuis on he secondary side of HT [8-11]. Zero-volage (Z) and (ZC) Zero-curren swiching can be easily achieved using he leakage inducance of he HT in full-bridge converers based on phase-shif pulse widh modulaion (PWM) conrol echnique [1]. However, HT wih high urns raio is unaracive for he reason ha i magnifies volage and curren spikes in he ransformer secondary side, he volage sress across he oupu diode becomes much higher han he oupu volage, and demands he use of diodes wih high breakdown volage [13]. Moreover, leakage inducance of he ransformer induces high circulaing curren in he primary side, which can possibly, decrease he funcional life of P modules [1], hence large elecrolyic capaciors are required o preven inpu curren ripple, which will increase size and cos of he converer. Consequenly, all he disadvanages menioned associaed wih isolaed converers decrease is overall efficiency [1, 14, 15]. On he oher hand, non-isolaed dc-dc converer, such as he basic boos converer, suffers from he drawback of high volage sress on he swich and diode, which are equal o he oupu volage, discouraging is implemenaion in high volage applicaions. Moreover, his problem leads o a condiion of employing acive componens wih high volage and diode wih fas reverse recovery, effecively, conribuing o higher cos. Furhermore, even hough he oupu volage can heoreically approach infiniy, his canno be achieved experimenally due o he parasiic resisive elemens in he converer. ubsequenly, some researchers proposed he use of swiched capacior (C) circuis wih basic boos converer o furher boos he volage gain [16]. everheless, he impacs of parasiic elemens, which can sill affec he pracical aainable volage gain and efficiency of he C-based boos converer, remain o be invesigaed. II. PROPOED EXTEDABLE WITCHED (C) CELL TECHIQUE DERIED HIH AI BOOT AD BUCK-BOOT DC-DC COERTER Proposed C-cell for boos and buck-boos Dc-Dc converers are shown in Fig. 1 and. The -sage Ccells for boh boos and buck-boos dc-dc converers can be formed by equal number of capaciors and diodes. The Cs are conneced beween he source and he load in such a way ha during he O ime of he wich, Cs are conneced in series o supply he load, while during he OFF ime of he swich Cs are conneced in parallel o be charged hrough he inducor. Furhermore, higher volage gain is achieved by

3 adding number of C-cells, so ha even a a smaller O ime of he swich higher oupu volage is achieved compared o he basic boos and buck-boos converers. As a resul of reducing he O ime of he swich is o achieve lower ripple is produced on he inpu curren, also curren ripples of he power devices can be reduced. Due o exreme duy raio severe recifier reverse-recovery problem is inheried o he converers. These problems can reduce he overall efficiency of he converer. As he name suggess in Fig. 1 and, he boos C-cell is inegraed wih he basic boos converer and buck-boos C-cell is inegraed wih he basic buck-boos converer, so ha he forward boos diodes D Fb1,,3 and forward buck-boos diodes D Fbb1,,3 are conneced in he same direcion as he oupu recifier diode D O. b 4 C Fb C Rb D III. TEADY TATE OPERATIO OF THE PROPOED - TAE C-CELL DERIED BOOT AD BUCK-BOOT DC-DC COERTER The -sage C-cell boos and buck-boos converers have also been discussed by auhors in [17]. In conras, o form n- sage C-cell, forward capaciors C Fb3 C Fb-n, canno be conneced direcly wih capaciors C Fb1 and C Fb. As seen from Fig., reverse diode D Rb1 D Rb-n and reverse capacior C Rb1 C Rb-n a (reverse exension) is conneced beween each (forward exension) of C-cell nework. (4) DFb1 CFb DRb1 CFb3 DRb-n CFb-n Magneic energy Recifier CFb1 DFb CRb1 DFb3 CRb-n DFb-n bb 4 CFbb1 DFbb CRbb1 DFbb3 CRbb-n DFbb-n Magneic energy Recifier DFbb1 CFbb DRbb1 CFbb3 DRbb-n CFbb-n Fig. 1. Proposed exendable C-cells; Boos C-cell, Buck-boos C-cell. C-sages can be exended o n number, such ha he number of boos C-sages can be exended a he rae of; b ( ndrb ndrb ) n and he number of buck-boos Csages can be exended a he rae of; DFb bb ( ndrbb ndrbb ) n where; DFbb n and DFb n represen DFbb he oal number of forward biased boos and buck-boos diodes. Furhermore, n represens he oal number of DRb reverse biased boos diodes and n represens he oal DRbb number of reverse biased buck-boos diodes. Therefore, is b he oal number of boos C-sages and bb is he oal number of buck-boos C-sages. According o he vol second balance on he inducor, we have. D. T ( C )(1 D) T ( C )(1 D) T (1) Fb Fbb. D. T C (1 D) T C (1 D) T () Each forward boos C Fb capacior conneced in he C nework adds up a volage equal o (3). While, each forward buck-boos C Fbb capacior conneced in he C nework adds up a volage equal o (4) C C (3) Fb Rb Rbb Rb Fig.. n-age C inegraed swich mode Dc-Dc converers; boos, buck-boos. Operaing modes for boos and buck-boos -sage Ccells: When he inducor curren is coninuous, here are hree operaing modes for he proposed converers. Fig. 3 shows he key waveforms for n-sage C-cell boos and buck-boos dc-dc converers. Where is he driving signal of he swich Q; CFb1, and CFb are he volages of capaciors C Fb1 and C Fb, respecively; while CRb1 and C Fb3 are he volages of capaciors C Rb1 and C Fb3 respecively; and i L is he curren of he inducor. [ 1]; Mode1: During ime [ -], swich Q is conducing, and he inpu volage source charges L, and C Fb charges C Rb1. Meanwhile, C Fb3, C Fb and C Fb1 are in series wih he volage source o supply he load hrough Q. Thus, volages of CRb1, CRb and CRb3 decrease. [1 ]; Mode: During ime, [ 1 - ], CRb3 increases while CRb1 decreases. As he volages of CRb1 and C Fb3 become equal before he swich conducs, we have CRb1 = C Fb3. [ T]; Mode3: During ime, [ -T ], he swich is urned OFF. Due o he fac CRb1 > C Fb3, D Fb3 coninues o conduc and D Fb remains OFF. L charges C Fb1 via D Fb3, and charges C Fb and C Fb3 via D Fb3 while C Rb1 discharges. The pahs of curren flow for -age C-cell derived boos Dc-Dc converer are shown in Fig. 4.

4 3 E On i L CFb1, CFb CRb1 CFb3 CRb- CFb- M1 Off M Off 1 T T + 1 T + Fig. 3. eady sae operaion wave form for n-sage C-cell derived boos and buck-boos dc-dc converers. M3 On (c) Fig. 5. Curren flow for n age C-cell derived buck-boos Dc-Dc converer, when swich; O, OFF, (c) OFF. Moreover, boos and buck-boos C-cell derived dc-dc converers oupu volage; bo and bbo is given in (5) and (6) respecively (5) bo CFb 1 CFb CFb ( ) bbo CFbb 1 CFbb (6) CFbb ( ) ince no C-sages are conneced o he basic boos and buck-boos converers shown in Fig. and respecively, he volage gain of he boos and he buck-boos converer can be given as (7) and (8) respecively O 1 M (7) O M (8) Moreover, he volage gain of he boos C-cell inegraed wih he basic boos converer and he volage gain of he buck-boos C cell inegraed wih he basic buck-boos converer can be given as (11) and (1) respecively M M O O 1 1 b. b (11) D 1 D 1 D 1 D D D bb D. bb (1) D 1 D 1 1 D (c) Fig. 4. Curren flow for n age C-cell derived boos Dc-Dc converer, when swich; O, OFF, (c) OFF. The descripion of operaing modes for -sage C-cell buck-boos derived Dc-Dc converer is same as -sage Ccell boos derived Dc-Dc converer. Therefore, pahs of curren flow for -sage C-cell derived buck-boos Dc-Dc converer are shown in Fig. 5. I. TETI PARAMETER FOR IMULATIO AD EXPERIMET ERIFICATIO In order o verify he proposed dc-dc converers, boos converer wih 4 C-sages is compared wih he basic boos converer in he laboraory by aking he experimenal resuls for boh he converers. TABLE I TETI PARAMETER FOR EXPERIMET PROTOTYPE 4-age C-cell derived Parameer boos dc-dc converer I (DC) 35 and 45 OUT (DC) 38 f s (khz) 1 WOUT 1. EXPERIMET REULT Boos converer exension of Cs o n-sages shown in Fig has a simple circui configuraion and a high volage gain. Therefore, proposed 4-sage C-cell derived boos dc-dc

5 4 converer is aken as he example for experimen resuls. To evaluae he impac of he proposed exendable C-cell echniques. Prooype was fabricaed in he laboraory wih a full load of 1 W. Tesing parameers are lised in Table I. Experimen waveforms shown in Fig. 6 and show he volage sress on swich CE, inpu inducor curren i L, oupu volage O, and inpu volage I. Fixed oupu volage o of 38 DC is exraced from inpu volage, varied from 35 and 45 DC a full load 1 W, simply by conrolling he O ime (Duy %) of he swich Q as shown in Fig 6 and respecively. When he inpu volage was 35 DC, he O ime of he proposed 4-sage C-cell boos derived converer was 73 %. Moreover, when he inpu volage was 45 DC he O ime he O ime of he proposed 4-sage C-cell boos derived converer was 65 %. I is obvious in Fig 6; he O ime for he proposed 4-sage C-cell boos derived converer is less han 75 %. Comparaively, he inducor curren ripple Δi L and urn-off curren of he swich is lower. As a resul of reducing he O ime of he swich is o achieve lower ripple is produced on he inpu curren, also curren ripples of he power devices can be reduced. The efficiency of he proposed converer wih differen inpu volages (35 and 45 DC ) is shown in Fig. 7. The oupu volage of he proposed converer is regulaed a 38. The resuls represen ha he proposed converer has lower efficiency a lower inpu because of higher conducing loss accompanied by higher inpu curren, due o higher O ime of he swich. The highes sysem efficiency for 45 Dc inpu volage appeared % a Po = 1 W load. Fig. 6. Experimen resuls of proposed boos converer wih 4 C-sages; 35 in o 38 ou, 45 in o 38 ou. Efficiency (%) ou 45-in 35-in Load (W) Fig. 7. Efficiency comparison beween proposed boos converer wih 4 C-sages in Fig. 6. REFERECE [1] Q. Zhao, F. Tao, Y. Hu, and F. C. Lee, "Acive-clamp DC/DC converers using magneic swiches," in Applied Power Elecronics Conference and Exposiion, 1. APEC 1. ixeenh Annual IEEE, 1, pp I. COCLUIO This paper, proves ha he volage gain of he boos converer wih proposed 4-sage C-cell is higher han he basic boos converer for he same duy raio, a he cos of lower efficiency as he C-cell sages are increased, which is due o increase in componen coun. However if he objecive is o obain he same volage gain, he 4-sage C-cell boos based converer gives he same gain a a lower duy raio, resuling in increase of efficiency compared wih he basic boos converer. Even hough he cos of 4-sage C based boos converer is higher han ha of a basic boos converer, i allows he exension of he volage gain ha would oherwise no be pracically viable wih he basic boos. Furhermore, he difference in erms of efficiency for basic boos compared wih 4-sage C based boos converer is quie marginal, especially for pracical duy in he range of All his assures he suiabiliy of C-based boosconverer o replace basic boos converer for high volage gain applicaion. [] M. Prudene, L. L. Pfischer,. Emmendoerfer, E. F. Romaneli, and R. ules, "olage muliplier cells applied o non-isolaed DC DC converers," IEEE Transacions on Power Elecronics, vol. 3, pp , 8. [3] K.-B. Park, H.-W. eong, H.-. Kim,.-W. Moon, and M.-J. Youn, "Inegraed boos-sepic converer for high sep-up applicaions," in 8 IEEE Power Elecronics pecialiss Conference, 8, pp

6 5 [4] H.-W. eong, K.-B. Park,.-W. Moon, and M.-J. Youn, "ovel dual inducor-fed DC-DC converer inegraed wih parallel boos converer," in 8 IEEE Power Elecronics pecialiss Conference, 8, pp [5] R.-J. Wai and R.-Y. Duan, "High sep-up converer wih coupledinducor," IEEE Transacions on Power Elecronics, vol., pp , 5. [6] E. J. Copple, "High efficiency DC sep-up volage converer," ed: oogle Paens, [7] A. Amir, J. elvaraj, and. Rahim, "udy of he MPP racking algorihms: Focusing he numerical mehod echniques," Renewable and usainable Energy Reviews, vol. 6, pp , 16. [8]. Iqbal,. K. ingh, and R. Besar, "A dual-mode inpu volage modulaion conrol scheme for volage muliplier based X-ray power supply," IEEE Transacions on Power Elecronics, vol. 3, pp , 8. [9] D. Zhou, A. Piekiewicz, and. Cuk, "A hree-swich high-volage converer," IEEE Transacions on Power Elecronics, vol. 14, pp , [1] J. un, X. Ding, M. akaoka, and H. Takano, "eries resonan ZC-PFM DC-DC converer wih mulisage recified volage muliplier and dual-mode PFM conrol scheme for medical-use high-volage X-ray power generaor," IEE Proceedings-Elecric Power Applicaions, vol. 147, pp ,. [11] A. Amir,. Taib, and. Iqbal, "olage muliplier-based coninuous conducion LCCL series resonan inverer fed high volage DC-DC converer," in Indusrial Elecronics and Applicaions (IIEA), 13 IEEE ymposium on, 13, pp [1] F. L. Tofoli, D. de Casro Pereira, W. J. de Paula, and D. d.. O. Júnior, "urvey on non-isolaed high-volage sep-up dc dc opologies based on he boos converer," IET Power Elecronics, vol. 8, pp , 15. [13].. Lee,. Iqbal, and M. Kamarol, "Conrol of ZC-R invererfed volage muliplier-based high-volage DC DC converer by digially uning ank capaciance and slighly varying pulse frequency," IEEE ransacions on power elecronics, vol. 7, pp , 1. [14] Z. Chen,. Liu, and L. hi, "A sof swiching full bridge converer wih reduced parasiic oscillaion in a wide load range," Power Elecronics, IEEE Transacions on, vol. 9, pp , 14. [15] W. Li and X. He, "Review of nonisolaed high-sep-up DC/DC converers in phoovolaic grid-conneced applicaions," IEEE Transacions on Indusrial Elecronics, vol. 58, pp , 11. [16] B. Wu,. Li, Y. Liu, and K. M. medley, "A ew Hybrid Boosing Converer for Renewable Energy Applicaions," Power Elecronics, IEEE Transacions on, vol. 31, pp , 16. [17] E. H. Ismail, M. A. Al-affar, A. J. abzali, and A. A. Fardoun, "A family of single-swich PWM converers wih high sep-up conversion raio," IEEE Transacions on Circuis and ysems I: Regular Papers, vol. 55, pp , 8.