Research Article A High Voltage Ratio and Low Ripple Interleaved DC-DC Converter for Fuel Cell Applications

Transcription

1 The Scienific World Journal Volume 2012, Aricle ID , 11 pages doi: /2012/ The cienificworldjournal Research Aricle A High Volage Raio and Low Ripple Inerleaved DC-DC Converer for Fuel Cell Applicaions Long-Yi Chang, Kuei-Hsiang Chao, and Tsang-Chih Chang Deparmen of Elecrical Engineering, Naional Chin-Yi Universiy of Technology, No. 57, Secion 2, Zhongshan Road, Taiping Disric, Taichung 41170, Taiwan Correspondence should be addressed o Kuei-Hsiang Chao, chaokh@ncu.edu.w Received 10 Ocober 2012; Acceped 30 Ocober 2012 Academic Ediors: N. H. Afgan and M. Cepin Copyrigh 2012 Long-Yi Chang e al. This is an open access aricle disribued under he Creaive Commons Aribuion License, which permis unresriced use, disribuion, and reproducion in any medium, provided he original work is properly cied. This paper proposes a high volage raio and low ripple inerleaved boos DC-DC converer, which can be used o reduce he oupu volage ripple. This converer ransfers he low DC volage of fuel cell o high DC volage in DC link. The srucure of he converer is parallel wih wo volage-doubler boos converers by inerleaving heir oupu volages o reduce he volage ripple raio. Besides, i can lower he curren sress for he swiches and inducors in he sysem. Firs, he PSIM sofware was used o esablish a proon exchange membrane fuel cell and a converer circui model. The simulaed and measured resuls of he fuel cell oupu characerisic curve are made o verify he correcness of he esablished simulaion model. In addiion, some experimenal resuls are made o validae he effeciveness in improving oupu volage ripple of he proposed high volage raio inerleaved boos DC-DC converers. 1. Inroducion Owing o worldwide energy crisis and awareness of environmenal proecion in recen years, o seek for subsiue energy has become an imporan issue. Among many subsiue energies, solar energy, wind energy, hydroelecric power, biomass energy, and fuel cells are green energies wih poenial developmen. As for fuel cells, here end o have been more and more researches and applicaions recenly. The fuel cell is a clean energy wihou polluion. Is energy, derived from reversed reacion of elecrolyzed waer, produces dynamic power. Only waer is produced afer he reacion; hence, here is hardly any environmenal polluion. Fuel cells as a source of power are usually applied o elecric hybrid auomobiles, disribued elecric generaion sysem, and porable and saionary power. Among hem proon exchange membrane fuel cells (PEMFCs) are he mos commonly used because of he following meris: (1) lower emperaure during operaion, accordingly leading o rapid urning on and off and rapid reacion o he load change;(2)loweroperaionpressure,huswihhighersafey; (3) easily se in mode sysem; and (4) lower emission raio and higher conversion raio [1 4]. Alhough he proon exchange membrane fuel cell has he advanages menioned above, due o is own acivaion loss, ohmic loss, and concenraion loss, he oupu volage is lowered as a resul of load increase. Namely, he fuel cell lowers he oupu volage bu raises he oupu curren gradually as he oupu power rises under he added load. Thus, i is a low-volage high-curren oupu equipmen. If we can ransfer he low volage produced by he fuel cell o high volage, sending i o DC link, here will be a wider range of applicaion [5 13].In order o upgrade he fuel cell volage oupu o he necessary elecriciy level and avoid he unseady volage caused by load change, i is necessary o adjus he fuel cell energy by means of power elecronic echnique, hus keeping seady he oupu volage. Based on his, presened in his paper is a high volage raio inerleaved DC-DC converer parallelly conneced and furher inerleaved by means of wo ses of volagedoubler boos converers. So besides he advanages of high volage raio converer, also because of he effec of parallel connecion, he curren is dispersed ino four roues, hus lowering he curren sress of he swich and inducance. In his way i can wihsand he high curren oupu while here is a high load. Through he parallel connecion of wo ses of

2 2 The Scienific World Journal I FC L 1 L 2 V FC C i S 1 S 2 C 1 C o R 1 R 2 Elecronic load D 3 D 4 L 3 L 4 S 3 S 4 C 2 S 1 S 2 S 3 S 4 PIC 18F8720 Figure 1: The sysem of he presened dual inerleaved volage doubler of high volage raio converer. converers and conrolling heir inerleaved volage, i is possible o lower he oupu volage ripple raio. Figure 1 is he srucure of he high volage inerleaved DC-DC converer presened in his paper. The fuel cell provides elecriciy for he dual inerleaved volage doubler of high volage raio converer. Elecronic load is used o es he amoun of load (ligh or heavy load); also microconroller PIC 18F8720 manufacured by Microchip company is used for closed loop conrol. Because wo volage-doubler boos converers are parallelly conneced o inerleave he oupu volage, he oupu volage ripple can be significanly reduced. 2. Fuel Cells There is a grea variey of fuel cells; also here are differen ways o classify hem. The common approach is o classify hem according o he various qualiies of he elecrolye. Thus, hey can be divided ino he following six kinds: (1)proonexchangemembranefuelcell,PEMFC, (2) alkaline fuel cell, AFC, (3) phosphoric acid fuel cell, PAFC, (4) molen carbonae fuel cell, MCFC, (5) solid oxide fuel cell, SOFC, (6) direc mehanol fuel cell, DMFC. Among hem, he proon exchange membrane fuel cell is he bes choice when we choose fuel cells for he source of he applied power because of he following reasons: (1) lower operaion emperaure, hus i can be rapidly urned on and off; (2) lower operaion pressure, hence greaer safey; (3) i can be easily se ino mode sysem; (4) lower emission raio and higher conversion raio Mold Building of Fuel Cells. As for fuel cells, his paper adops he NEXA proon exchange membrane fuel cell Table 1: Specificaions of he Ballard NEXA proon exchange membrane fuel cell [14]. Power Emissions Physical Fuel Raed power Operaing volage range Volage a raed power Curren a raed power Sarup ime Noise Waer Dimensions Mass Puriy Pressure Consumpion 1200 W V DC 26 V 46 A 2 minues 72 dba 870 ml/hr cm 13 kg 99.99% H 2 (vol) bar <18.5 SLPM produced by Ballard Company. The specificaions of his proon exchange fuel cell are shown in Table 1 [14]. In building up he proon exchange membrane fuel cell mah model, currenly here are many simple precise model parameers and calculaion formulae being presened and developed [15, 16]. In his paper we refer o he elecrochemisry formulae already presened o build up he mah model of he proon exchange membrane fuel cell, also wihin he range of he load curren operaion simulae he characerisic curve of he oupu volage and power rae of he fuel cell [15, 16]. Themahmodelofheproonexchangemembranefuel cell is shown in V sack = NV FC, V FC = E Nerns V ac hmic V con. Therein, V sack is he sack oupu volage; N he number of cells forming he sack; V FC he oupu volage of he fuel cell; E Nerns he oupu volage produced by every piece of fuel cell (1)

3 The Scienific World Journal 3 in hermodynamics; V ac he acivaion loss; hmic he ohmic loss; V con he concenraion loss. And he hermodynamic oupu volage of every piece of fuel cell can be shown as follows. E Nerns = (T ) [ T ln ( ] ) 1 P H2 2 ln( ) P o2. Therein, T is he cell emperaure (in Kelvin); P H2 is he parial pressures of hydrogen; P O2 is he parial pressures of oxygen. As for acivaion loss volage, i can be shown his way: (2) V ac = [ ξ 1 ξ 2 Tξ 3 T ln ( C O2 ) ξ4 T ln(i FC ) ]. (3) Therein, ξ 1, ξ 2, ξ 3, ξ 4 is he parameric coefficien for each cell model; C O2 he concenraion degree of oxygen in he caalyic inerface of he cahode; I FC he fuel cell curren. And he respecive coefficiens of he acivaion loss are ξ 2 = ln(a) ln ( ) C H2, P O2 C O2 = [ e (498/T) ]. (4) Therein, A is he cell acive area, C H2 is he liquid phase concenraion of hydrogen. As for ohmic loss volage, i can be shown as follows: hmic = I FC (R M R C ). (5) Therein, R M is he resisance coefficien of he membrane, R C is he resisance coefficien consan o proons ransfer hrough he membrane. The resisance coefficien of he membrane herein is R M = ρ M L A. (6) Therein, ρ M is he specific resisiviy of he membrane o he elecron flow, L is he hickness of he membrane. The resisance coefficien of he membrane can be shown o be { [ ( ) IFC ρ M = A ( ) T 2 ( ) 2.5 ]} IFC A {[ ( ) ]} IFC / λ e [4.18 (T303)/T]. A (7) Therein, λ is he adjusmen parameer, he range of which is beween 14 and 23. Concenraion loss formula is shown o be ( V con = B ln 1 j ). (8) j max R ac R con R M E Nerns R a hmic Vc I FC Load V FC Figure 2: The equivalen circui of he fuel cell. Therein, B is he consan variable depending on he cell ype and is working saus; J is he curren densiy of he cell; j max is he maximum curren densiy. Therein, he curren densiy of he cell is j = I FC A. (9) Therefore, he equivalen circui of he fuel cell can be worked up as in Figure 2. If we ake he dynamic response of he fuel cell ino consideraion, when wo differen subsances come ino conac or he load curren flows from one end o he oher, accumulaion of charge is produced on he conac area. In he fuel cell, he layer of change beween he elecrode and elecrolye (or compac conac face) will accumulae elecric charge and energy, whose acion is similar o capaciance. So when he load curren changes, here will be charge and discharge phenomena happening on he charge layer. Meanwhile, acivaion loss volage and concenraion loss volage will be under he influence of ransien response, causing delay. Bu ohmic loss volage will no be influenced or delayed. We can ake his ino consideraion o le firs-order lag exis in acivaion loss volage and concenraion loss volage. Thus, is dynamic response equaion can be shown o be [15, 16] V FC = E Nerns hmic V c, dv c = I FC d C V c τ, τ = C R a. (10) Therein, τ is he ime consan; C is he equivalen capaciance of he sysem; V c is he dynamic volage of he fuel cell; R a is he equivalen resisance. The analysis shown above can be used o build up he mahemaical model of he proon exchange membrane fuel cell so as o carry on he simulaion analysis of he sysem The Simulaion of he Fuel Cell. In his paper PSIM simulaion sofware is used o build up he simulaed model

4 4 The Scienific World Journal of he proon exchange membrane fuel cell. Is composiion module is shown in Figure 3, in which he upper righ increased k value is 42, represening he sack amoun of he single cell in he cell sack. The simulaed circui of he equivalen capaciance dynamic acion is shown in Figure 4. The DLL in Figure 3 is he dynamic link library of PSIM simulaion sofware. Through sofware Microsof Visual C 6.0, he necessary DLL file for linking can be se up. By means of Microsof Visual C 6.0, we can make use of programs o wrie he mahemaical formulas in hem, saving he rouble of building up numerous inner circui figures. Afer building up fuel cell model, we have is load currenoperaedwihinfixedraeandvalue.thehydrogen and oxygen pressures are, respecively, se up a 1 bar. The characerisic curve of he simulaed fuel cell oupu volage and power rae is shown in Figure 5. The upper par of Figure 5 is he curve of he curren and volage of he fuel cell, while he lower par is he power rae curve. Compared wih Figure 6, he acual measuring oupu curve of Ballard Co. NEXA fuel cell, we can find boh of he curves of he oupu characerisics are closely similar. Only because he curve of Figure 6 is formed by connecing from poin o poin, i follows ha here is sligh difference beween hem. 3. Single Se of Volage-Doubler Boos Converer Shown in Figure 7 is he circui srucure of single se volage-doubler boos converer [17, 18]. I is made up of inerleaved boos converers wih a clamp capacior C 1.The circui srucure is simple and i can reach he same high volage raio wih lower duy cycle. Therefore, i can reduce he conducion loss of he swich, o furher upgrade he efficiency of he whole converer. The work heorem of he whole circui can be divided ino four operaion modes, of which he equivalen circuis are, respecively, shown in Figures 8(a) 8(d). The equivalen circuis of mode 1 and mode 3 are exhibied in Figures 8(a) and 8(c). In his siuaion, swiches S 1 and S 2 are urned on. Inpu volage V i says beween inducance L 1 and L 2, making he inducance curren increase linearly, and begins o deposi energy, and he load curren is provided by capacior C o. The change of he inducance curren i L1 and i L2 can be shown in V i = L 1 di L1 d = L 2 di L2 d. (11) Figure 8(b) is he equivalen circui in mode 2, in which swich S 1 is urned off while S 2 is urned on. The inducance curren in forward direcion conducs diode D 1. In he meanime inducance L 1 volage releases energy o clamp capacior C 1, charging capacior C 1, while inducance L 2 goes on deposiing energy. The change of he inducance curren i L1 can be shown in di L1 d = V i V C1 L 1. (12) The equivalen circui of mode 4 is exhibied in Figure 8(d), in which swich S 1 is urned on and swich S 2 is urned off. The inducance curren in forward direcion conducs diode D 2. Then inducance L 2 and clamp capacior C 1 simulaneously release energy o oupu capacior C o and load. The change of inducance curren i L2 can be shown in di L2 d = V i V C1 V O L 2. (13) Through he analysis of he four modes menioned above, only V C1 capacior volage is an unknown variable. According o circui srucure and KVL heorem, inducance L 1, L 2 and he volage of diode D 1 plus clamp capacior volage V C1 should be zero, and in seady sae he average volage of inducance L 1 and L 2 is zero. Therefore, i is known ha he average volage of D 1 is idenical wih clamp capacior volage V C1.ThewaveformofD 1 volage is exhibied in Figure 9, so he clamp capacior volage V C1 can be shown in V C1 = V D1, avg = V O 2. (14) Afer geing he clamp capacior volage, we work ou (11) (13) according o vol-second balance heorem and ge (15). Then we carry in (14) oworkou(16). Therefore, we can infer ha he volage increase of he converer is shown in (17), in which T is he swiching cycle, D is he duy cycle and f is he swiching frequency: V i V C1 L 1 V i (V O /2) L 1 (1 D)T V i L 1 DT = 0, (15) (1 D)T V i DT = 0, L 1 (16) V O = 2V i 1 D. (17) From (17) i is known ha volage-doubler boos converer can reach he same high volage raio wih a shorer duy cycle. Moreover on accoun of he added clamp capacior, he volage of he swich can be reduced o only half of he oupu volage. This can be known from he swich volage of (18) while operaing under mode 2 and mode 4: in V ds1, max = V C1 = V O 2, V ds2, max = V C1 = V O 2. (18) The oupu and inpu power can be shown, respecively, P O = V O 2 R, (19) P i = V i I i = V i (I L1 I L2 ). (20) From (20), assuming L = L 1 = L 2,ifollows P i = V i I i = V i 2I L. (21)

5 The Scienific World Journal 5 P H2 P O2 P H2 DLL1 P O2 DLL E Nerns 42 K V FC E Nerns. DLL P O2 DLL2 V ac DLL V ac. DLL V ac V con V C DLL3 DLL V con V con. DLL DLL4 DLL hm hm. DLL Figure 3: The fuel cell model buil up by means of PSIM sofware. V ac V ac V con V con R a T V C /T /C C ± V C V C Figure 4: The simulaed circui of capaciance equivalen dynamic acion buil up by means of PSIM sofware. Vfc (V) I fc V fc V fc I fc Pfc (W) I fc (A) Figure 5: The curve of he fuel cell oupu by means of PSIM sofware simulaion.

6 6 The Scienific World Journal Ne volage (V) Power Ne volage Ne curren Ne curren (A) Figure 6: The curve of he acual measuring oupu of Ballard Co. NEXA fuel cell [14]. I i V i C i S 1 S 2 L 1 L 2 C 1 C o R o Power (W) Figure 7: Circui srucure of volage-doubler boos converer. If here is no power loss of he converer, hen P o = P i wih he following resul V i 2I L = V O 2 I L = = R = (2V i/(1 D)) 2 R 4V 2 i (1 D) 2 R, 2V i (1 D) 2 R, I L1 = I L2 = I L. (22) The waveform of inducance currens is exhibied in Figure 10, in which hough i L1 and i L2 waveforms are in complemenary relaion, is maximum and minimum inducance curren are he same. Hence based on I L1, he relaed formulae of he maximum and minimum inducance curren are, respecively, shown in I L1, max = I L1 Δi L1 2 = 2V i (1 D) 2 R V idt, 2L 1 I L1, min = I L1 Δi L1 2 = 2V i (1 D) 2 R V idt. 2L 1 (23) The condiion on which he converer can be operaed in coninuous curren mode is ha i L1,min and i L2,min should a leas be greaer han zero. So he boundary condiion of coninuous and disconinuous inducance curren is I L1, min = 0 = 2V i (1 D) 2 R V idt. (24) 2L 1 So we ge L 1, min = D(1 D)2 R. (25) 4 f Because he maximum and he minimum inducion currens of inducance L 1 and L 2 are he same, he minimum inducion raes derived from L 1 and L 2 are idenical. Hence, if he converer is o be operaed in he coninuous curren mode, inducance L 1 and L 2 mus a leas be greaer han or equal o L 1, min. From he mahemaic funcion D(1 D) 2 of (25), i can be observed if D value is a 1/3, he mahemaic funcion D(1 D) 2 will have he maximum value, which also means he maximum D value creaed by (25) is 1/3.Hence in designing inducance, when D as 1/3 is subsiued ino (25), and le he inducance value derived from calculaion be muliplied by surplus value 1.25, i can be assured ha he inducance curren can really work in he coninuous curren mode. The load impedances of so-called ligh load and heavy load in his paper, are respecively, 2,020 Ω and 450 Ω. Soa swiching frequency 15 khz, heavy load duy cycle abou 0.85 when i is subsiued ino (25), he resul is ha in order o le he curren coninue under ligh load, he leas inducance should be 6.23 mh, while under heavy load i should be 179 μh. In his paper 260 μh is he opion o make i possible o be in coninuous curren conducion mode under heavy load. The change of oupu capacior curren is shown in he i Co of Figure 11. From Figure 11 we know he amoun of capacior elecric charge change as ΔQ = V ODT R O = C O ΔV O. (26) Then is volage ripple raio may be expressed as follows: So he resul is C O = ΔV O V O = DT R O C O. (27) D R O f (ΔV O /V O ). (28) Therefore in he converer, we can decide he size of he capacior according o he amoun of volage ripple raio. From (28) i is observed ha he oupu capaciy and duy cycle are in linear relaion. I means he designed oupu capaciy mus be greaer han he required capaciy wih he maximum duy cycle. In his paper volage ripple raio is se a 5%. When i is subsiued ino (28), he oupu capaciy is 2.5 μf. So 150 μf is seleced o make he volage ripple raio lower han 5%. By means of he above-described operaion mode of he converer, he swich conrol signal in he circui, inducance and capaciy curren waveform can be exhibied in Figure 11,

7 The Scienific World Journal 7 I i I i V i i L1 L 1 i L2 L 2 C i S 1 S 2 V C1 C o R o V i i L1 L 1 i L2 L 2 C i S 1 S 2 V C1 C o R o (a) (b) I i I i V i i L1 L 1 i L2 L 2 C i S 1 S 2 V C1 C o R o V i i L1 L 1 i L2 L 2 C i S 1 S 2 V C1 C o R o (c) (d) Figure 8: The four swich modes of volage-doubler boos converer in he duy cycle: (a) model 1, (b) model 2, (c) model 3, and (d) model 4. V D1 V C1 Mode Figure 9: Volage waveform of diode D 1 under each mode. S 1 S 2 i L1, i L2 i L1, i L2 i L1 i L2 I L1,max, I L2,max i CO I L1, I L2 I L1,min, I L2,min DT T Δi L1, Δi L2 ΔQ DT T /R o mode Figure 10: The waveform of he change of inducance curren. Figure 11: The swich signal, inducance, and capaciy waveforms under each operaion mode. and is inpu volage ripple and curren ripple can be shown in ( VO /2 V ΔI i i = V ) i (1 D)T L n L n = V (29) O 4V i (1 D)T; L n {L 1, L 2 }, 2L n ΔV Co = I O DT. (30) From (29) i is known ha he volage-doubler boos converer has he advanage of lower inpu curren bu he amoun of is oupu volage ripple is he same as he radiional high volage converer. Hence in his paper we se forh an amelioraed inerleaved volage-doubler boos converer. By means of he original volage-doubler boos converer parallelly conneced, making oupu volage inerleaved, so as o reduce oupu volage ripple, he flaw of greaer oupu volage is furher amelioraed. 4. The Presened Dual Inerleaved Volage Doubler of High Volage Raio Converer The circui srucure of he dual inerleaved volage doubler of high volage raio converer presened in his paper is shown in Figure 12. By means of parallelly conneced original volage-doubler boos converer o have he wo ses of upper and lower volage muually inerleaved, we can lower is oupu volage ripple by conrolling one se of heir swich conrol signals o make is oupu volage ripple offse ha of he oher se. In conrolling boh he upper and he lower

8 8 The Scienific World Journal I i Swich signal S 1 V i L 1 L 2 C i 1 C o S 1 S 2 C 1 R o Swich signal S 2 L 3 L 4 S 3 S 4 C 2 D 3 D 4 Vo2 Figure 12: The circui srucure of dual inerleaved volage doubler of high volage raio converer. Swich signal S 4 Swich signal S 3 Figure 14: The swich signal waveforms of dual inerleaved volage doubler of high volage raio converer. S 1 Swich signal S 1 S 2 Swich signal S 2 S 3 50 V Inpu volage V FC S 4 Oupu volage 500 V i L1, i L2 Figure 15: The swich signal and inpu/oupu volage waveforms under oupu power 43 W. i L3, i L4 1, 2 Mode Figure 13 are observed he oupu volage ripples of he wo converers V O1 and V O2. Through he phase displacemen of he swich conrol signal, he phase displacemen of wo ses of volage ripples is brough abou, hus resuling in he effec of lowering he oupu volage ripple. Figure 13: The ripple waveforms of swich conrol signal, inducance curren, and oupu volage under each operaion mode. ses of swiches S 1, S 2 and S 3, S 4 o make S 1, S 2 and S 3, S 4 swich conrol phase discrepancy 180 lead o volage ripple phase displacemen, he funcion of lowering volage ripple is hus achieved. And because he inerleaved swiches of hese wo ses of volage-doubler boos converers make he inpu curren circui divide ino four roues, hus furher lowering he curren sress of he inducance and swich, i is possible o wihsand he high curren of he oupu of he fuel cell under heavy load. Also i is conrolled by microconroller PIC18F8720. In his way he oupu volage can be kep seady a a fixed value. Figure 13 shows he conrol signal, inducance curren, and oupu volage ripple waveforms in he circui. From 5. Experimenal Resuls In order o prove he feasibiliy of he dual inerleaved volage doubler of high volage raio converer se forh in his paper, a es will be carried on under wo differen loads. The fuel cell produces oupu volage abou 26 o 43 V, o be upgraded o 300 V, and he elecronic load is, respecively, adjused a 2,020 Ω (abou oupu power 43 W) and 450 Ω (abou oupu power 200 W) under es. Figure 14 is he waveforms of he swich signal conrol in dual inerleaved volage doubler of high volage raio converer. Swiches S 1, S 3 and S 2, S 4 have respecive conrol phase discrepancy 180. Figures 15 and 16 show he waveforms of swich signal, he waveforms of fuel cell oupu volage and oupu volage of converer, respecively, under oupu power 43 W and 200 W. From he figures i is observed ha under differen loads, by conrolling he duy

9 The Scienific World Journal 9 Swich signal S 1 Swich signal S 1 Swich signal S 2 Inpu volage V FC 50 V Swich signal S 2 Inducance curren i L1 5 A Oupu volage 500 V Figure 16: The swich signal and inpu/oupu volage waveforms under oupu power 200 W. Inducance curren i L2 Figure 18: The swich signal, i L1 and i L2 inducance curren waveforms under oupu power 200 W. 5 A Swich signal S 1 Oupu volage ripple Swich signal S 2 2 A Inducance curren i L1 2 A Average volage 300 V Inducance curren i L2 Figure 17: The swich signal, i L1 and i L2 inducance curren waveforms under oupu power 43 W. Figure 19: The oupu volage ripple waveform of single volagedoubler boos converer under oupu power 43 W. cycle of he swich signal, he oupu volage of converer can be kep seady a 300 V. Figures 17 and 18 are he waveforms of swich signal and inducance curren i L1 and i L2 under respecive oupu power 43 W and 200 W. From he figures i is observed ha wih he gradual increase of loads, he inducance currens i L1 and i L2 are also on he increase o enable i o work in coninuous curren mode under higher oupu power. Figures 19 and 20 are he respecive oupu volage ripple waveforms of single se volage-doubler boos converer and he presened dual inerleaved volage-doubler of high volage raio converer. From Figures 19 and 20 i is observed ha hrough comparison we find here is improvemen in oupu volage ripple waveform. In Figure 19 he peak-opeak volage of he single se volage doubler boos converer is abou 15.8 V, while ha of he presened dual inerleaved volage doubler of high volage raio converer in Figure 20 is abou 9.. Their respecive volage ripple raios are 5.27% and 3.17%. Figures 21 and 22 are he respecive oupu volage ripple waveforms of single se volage doubler boos converer and he presened dual inerleaved volage doubler of high volage raio converer. From Figures 21 and 22 i is observed ha hrough comparison we find here is improvemen in Oupu volage ripple Average volage 300 V Figure 20: The oupu volage ripple waveform of he presened dual inerleaved volage-doubler of high volage raio converer under oupu power 43 W. oupu volage ripple waveform. In Figure 21 he peak-opeak volage of he single se volage-doubler boos converer is abou 36 V, while ha of he presened dual inerleaved volage doubler of high volage raio converer in Figure 22 is abou Their respecive volage ripple raios are 12% and 8.75%. Thus i is proved ha he dual inerleaved volage

10 10 The Scienific World Journal Acknowledgmen Oupu volage ripple This work was suppored by he Naional Science Council, Taiwan, under he Gran no. NSC E ET. References Average volage 300 V Figure 21: The oupu volage ripple waveform of single volagedoubler boos converer under oupu power 200 W. Oupu volage ripple Average volage 300 V Figure 22: The oupu volage ripple waveform of he presened dual inerleaved volage doubler of high volage raio converer under oupu power 200 W. doubler of high volage raio converer can improve he flaw of higher volage ripple raio of he original single se volagedoubler boos converer. 6. Conclusion This paper ses forh an amelioraed dual inerleaved volage doubler of high volage raio converer o improve he problem of oupu ripple volage of single se volage-doubler boos converer. Wih wo parallelly conneced volagedoubler boos converers o inerleave he oupu volage ripple, we furher lower he oupu volage ripple. No only does i mainain he advanages of volage-doubler boos converer, bu also, owing o he inerleaved single se converer wih wo separae curren roues and he wo ses of swiches of he double volage booser once again in parallel connecion leading o four separae curren roues, i is hus possible o furher lower he curren sress of he swich and inducance. Through es and experimen, his paper proves and confirms he feasibiliy of he presened dual inerleaved converer. [1] J. C. Amphle, R. F. Mann, B. A. Peppley, P. R. Roberge, and A. Rodrigues, A model predicing ransien responses of proon exchange membrane fuel cells, Journal of Power Sources, vol. 61, no. 1-2, pp , [2] R.F.Mann,J.C.Amphle,M.A.I.Hooper,H.M.Jensen,B. A. Peppley, and P. R. Roberge, Developmen and applicaion of a generalized seady-sae elecrochemical model for a PEM fuel cell, Journal of Power Sources, vol. 86, no. 1, pp , [3] J. M. Corrêa, F. A. Farre, and L. N. Canha, An analysis of he dynamic performance of proon exchange membrane fuel cells using an elecrochemical model, in Proceedings of he 27h Annual Conference of he IEEE Indusrial Elecronics Sociey (IECON 01), pp , December [4] D. M. Ali, A simplified dynamic simulaion model (prooype) for a sand-alone Polymer Elecrolye Membrane (PEM) fuel cell sack, in Proceedings of he 12h Inernaional Middle Eas Power Sysem Conference (MEPCON 08), pp , March [5] R. J. Wai, C. Y. Lin, and C. C. Chu, High sep-up DC-DC converer for fuel cell generaion sysem, in Proceedings of he IEEE Indusrial Elecronics Sociey (IECO 04), vol. 1, pp , November [6] R. J. Wai and R. Y. Duan, High sep-up converer wih coupled-inducor, IEEE Transacions on Power Elecronics, vol. 20, no. 5, pp , [7] R. J. Wai, L. W. Liu, and R. Y. Duan, High-efficiency volage-clamped DC-DC converer wih reduced reverserecovery curren and swich-volage sress, IEEE Transacions on Indusrial Elecronics, vol. 53, no. 1, pp , [8] P. Thounhong, S. Raël, and B. Dava, Conrol sraegy of fuel cell and supercapaciors associaion for a disribued generaion sysem, IEEE Transacions on Indusrial Elecronics, vol. 54, no. 6, pp , [9] P. Thounhong, S. Raël, and B. Dava, Analysis of supercapacior as second source based on fuel cell power generaion, IEEE Transacions on Energy Conversion, vol.24,no.1,pp , [10] S. K. Changchien, T. J. Liang, J. F. Chen, and L. S. Yang, Novel high sep-up DCDC converer for fuel cell energy conversion sysem, IEEE Transacions on Indusrial Elecronics, vol. 57, no. 6, pp , [11] P. Thounhong, S. Pierfederici, J. P. Marin, M. Hinaje, and B. Dava, Modeling and conrol of fuel cell/supercapacior hybrid source based on differenial flaness conrol, IEEE Transacions on Vehicular Technology, vol. 59, no. 6, pp , [12] A. Shahin, M. Hinaje, J. P. Marin, S. Pierfederici, S. Rael, and B. Dava, High volage raio DC-DC converer for fuel-cell applicaions, IEEE Transacions on Indusrial Elecronics, vol. 57, no. 12, pp , [13] C. T. Pan and C. M. Lai, A high-efficiency high sep-up converer wih low swich volage sress for fuel-cell sysem applicaions, IEEE Transacions on Indusrial Elecronics, vol. 57, no. 6, pp , 2010.

11 The Scienific World Journal 11 [14] Daa shee of a 1.2 kw Ballard NEXATM power module, ballard power sysems inc. Ballard Power Sysems Corp. AN , [15] L. P. Lima, F. A. Farre, D. B. Ramos e al., PSim mahemaical ools o simulae PEM fuel cells including he power converer, in Proceedings of he 35h Annual Conference of he IEEE Indusrial Elecronics Sociey (IECON 09), pp , November [16] J. Jia, Q. Li, Y. Wang, Y. T. Cham, and M. Han, Modeling and dynamic characerisic simulaion of a proon exchange membrane fuel cell, IEEE Transacions on Energy Conversion, vol. 24, no. 1, pp , [17] Y. T. Jang and M. M. Jovanović, Inerleaved boos converer wih inrinsic volage-doubler characerisic for universal-line PFC fron end, IEEE Transacions on Power Elecronics, vol. 22, no. 4, pp , [18] C. T. Pan, C. M. Lai, M. C. Cheng, and L. T. Hsu, A low swich volage sress inerleaved boos converer for power facor correcion, in Proceedings of he Inernaional Conference on Power Elecronics and Drive Sysems (PEDS 09), pp , January 2009.

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