Design and Analysis of Soft-Switching Boost Converter

Transcription

1 ntenational Reseach Jounal of Enineein and Technoloy (RJET) e-ssn: lume: 0 ssue: 05 May-06 p-ssn: Desin and Analysis of Soft-Switchin Boost Convete Mohit Papika, Akash Gupta Depatment of Electical Enineein, Mahaana patap Collee of Technoloy, Gwalio Rajive Gandhi poudyoiki vishwavidyalaya,bhopal, ndia *** Abstact- n this pape a Zeo-Cuent Tansition Fouth Ode boost convete is poposed which offes sinificant To impove the efficiency thee ae two soft switchin schemes wee epoted in the liteatue []: advantaes ove conventional second ode boost convete. The fouth ode convete povides slihtly. Zeo voltae switchin (ZVS) duin tun-on. hihe voltae ain and the ipple in input cuent and. Zeo cuent switchin (ZCS) duin tun-off. output voltae is also educed. The zeo cuent tansition The selection of these schemes is device specific, i.e., cell which is also incopoated into the cicuit povides MOSFET o GBT. Althouh these soft-switchin futhe advantaes in tems of eduction of switchin losses fo nealy all the switchin devices. Mathematical techniques yield bette efficiency but, still thee ae some analysis of the poposed convete is done to find the dawbacks. vaious modes of opeation and thei timins. n ode to veify the soft switchin pefomance of this convete simulation is caied out in PSM. To futhe test the The ZCS tun-off has dawbacks such as: advantae povided by the poposed convete ove had Sinificant voltae stess on the main diode. switched convetes a compaative loss analysis is caied ncease in the conduction losses. out in MATAB fo vaious load conditions. The convete The esonant inducto in seies with the main pefomance is pedetemined fo a to 4 V, 0 W switch, which inceases the manetic losses. pototype in simulation and then compaed with To alleviate some of these dawbacks the zeo-cuent expeimental esults. Expeimental measuements ae in tansition/ zeo-voltae tansition (ZCT/ ZVT) techniques have close aeement with simulations. been poposed in liteatue [] - [].. ntoduction Dc-dc boost convetes ae most commonly used to delive hihe load voltaes fom iven low voltae souce. The conventional boost convete thouh suffes fom the followin disadvantaes: (i) ts full load efficiency is low on account of hihe switchin losses, (ii) Hih duty atio even fo modeate voltae ain ealization (iii) Exteme duty atio opeation unable to yield expected voltae ainn ode to eliminate some of these limitations, hihe ode boost pulse width modulated (PWM) convete ae developed. These convetes ive hihe voltae ain but at hihe switchin fequencies the full-load efficiency is still a limitation. Recently, moe soft-switchin techniques ae comin-up to ovecome the excessive switchin losses occuin in the conventional had-switched dc-dc convetes and to ealize hihe efficiencies fo the dc-dc convete at full-load conditions. Howeve, thee is not enouh liteatue covein the development of soft-switchin schemes fo fouth-ode convetes. Theefoe, the aim is to impove the efficiency of the fouth ode boost convete, belonin to hihe ode family, thouh soft-switchin usin the ZCT technique. Hee the softswitchin is ealized by inteatin the ZCT cell into the fouthode boost convete. This pape pesents some investiations on steady-state analysis and desin of one hihe-ode boost convete, Fouth-ode Zeo Cuent Tansition Boost Convete (FZCTBC). n a sinle switchin cycle the cicuit will undeo seven diffeent modes of opeation. The time intevals and the status of each switchin device is shown in the table iven below. V + - C C 0 R load 06, RJET mpact Facto value: 4.45 SO 900:008 Cetified Jounal Pae 08

2 ntenational Reseach Jounal of Enineein and Technoloy (RJET) e-ssn: lume: 0 ssue: 05 May-06 p-ssn: Fi.. Cicuit diaam of the zeo-cuent tansition fouthode boost convete.. Steady-state Analysis of zeo-cuent tansition fouth-ode boost convete A. Topoloical vaiations in each mode of opeation (D) Equivalent cicuit duin mode-v opeation C C (E) Equivalent cicuit duin mode-v opeation (A) Equivalent cicuit duin mode- opeation C C (F) Equivalent cicuit duin mode-v opeation (B) Equivalent cicuit duin mode- opeation C C (G) Equivalent cicuit duin mode-v opeation Fiues (A) to () ae opeatin modes (C) Equivalent cicuit duin mode- opeation Mode : (to<t<t) nitial Conditions: B. Opeation modes: On witin KC at node - i i D C V 0 i() t t ( )..() i i D Main diode cuent, 0 id () t t ( ) 06, RJET mpact Facto value: 4.45 SO 900:008 Cetified Jounal Pae 09 V.()

3 ntenational Reseach Jounal of Enineein and Technoloy (RJET) e-ssn: lume: 0 ssue: 05 May-06 p-ssn: And at,t=t, i(t)=,on equatin, ( ) t V0.() Mode : (t<t<t) n this mode a steady state cuent equal to flows thouh the main switch, and this mode continues till the auxiliay switch is fied, Duin this mode the main diode stae will be, v v v 0 C D main (as i eached steady state value ) v (t)=v t C cos ( t) cos tt c On KV, v vc v As D aux 0 (6) vc v 0 ettin dischaed and hence vc ( t) 0, v 0, i, steadyvalue D aux When And hence auxiliay diode stats conductin by the end of this mode, and with this cicuit entes into the next mode of opeation Mode : (t<t<t) nitial conditions: Applyin KC: i i c ; Mode 4: (t<t<t4): i (0) i i i d aux i i i dau x di dt vc On KV, vc v On solvin the above two equations, vc ( t t ) V cos w t t 0 ( ) V i 0 t sint Z.(5) Whee ;.(4) t t At, at the end of this mode vc t ( ) 0 On KC, i i daux On solvin above equations, V 0S in( ( t t)) vc ( t) S in( 0( t t))..(7) o c Whee And main switch cuent, is iven by V0 sin ( t t) i( t) ( Coso ( t t) o..(8) But, at t t4 At the end of this mode, i ( ) 0 t V sin ( t t ) ( ( ) 0 Cos o t t o 06, RJET mpact Facto value: 4.45 SO 900:008 Cetified Jounal Pae 00

4 ntenational Reseach Jounal of Enineein and Technoloy (RJET) e-ssn: lume: 0 ssue: 05 May-06 p-ssn: / o t4 t ( ) Cos (( ) ) o Sin ( t t).(9) t t ( C ( V -V 6 5 o o ( Sin ( t - t ))( Sin ( t - t ) o 5 4 ( / )..() Mode 5: (t4<t<t5) Mode 7: (t6<t<ts) Duin this mode, v v c Duin this mode main diode cuent eaches a steady state value and this mode continues till the main switch is tuned ON. t T At, 7 s (4) This mode is identical to the feewheelin stae of the conventional boost convete V V sin ( t t ) (cos( ( )) ) o 0 o t t4 z 0 t t At the end of this mode at 5, i ( t5) 0, On solvin, / t5 t Cos Sin ( t t ) o ( )( ( ( ))) o Mode 6: (t5<t<t6)..(0) The time minimum and maximum Ontimes fo SA ate sinal has to satisfy the followin to satisfy ZCT condition. C Dsaux min C C Dsaux max eqc Whee, eq * eq Duin this mode the main diode voltae will be fallin as the esonatin capacito is chain. On KC at node-, ic= dvc C dt sin ( t t) vc( t ) ( t t5) sin o( t t) ( t t5) C C On KV alon-, Vdmain=+vc V sin ( t t ) v t V t t t t o dmain ( ) O sin o ( ) ( 5) C..() () At the end of this mode, at t=t6, when vc chaes upto v ( ) 0, dmain t,main diode comes into conduction,i.e 6 V sin ( t t ) o 0 VO sin o( t6 t) ( t t5) C. Desin of ZCT-Fouth-Ode Boost Convete A. Powe stae components desin: The convete is desined with the followin specifications: oad nominal ated powe Po=0W,oad ltae =4 V,Switchin fequency,fs=00 KHz., oad ltae Ripple<5%,nput Cuent ipple=<0%. Final Powe Stae elements Desined ae: The paametes of the desined convete to meet the specifications ( <0% <5%) ae: =50 µh, =50 µh, C=00 µf, C=00 µf,. B. Resonant Tank Cicuit Desin: Hee, a simple desin pocedue is followed as explained below. Fom ZCS boost nomalized switchin fequency(fns) Vs. Gain(M) chaacteistics, fo a voltae ain of.0 it is obseved the combinations of nomalized switchin fequency and Q(Nomalized load) and chosen to be fo a Q=,the fns=0..by usin the desin equation as mentioned fom (4) to (6) and C have been obtained As =0.6µH,and C=70 n F. 06, RJET mpact Facto value: 4.45 SO 900:008 Cetified Jounal Pae 0

5 Q ntenational Reseach Jounal of Enineein and Technoloy (RJET) e-ssn: lume: 0 ssue: 05 May-06 p-ssn: The combination and ane of esonant tank cicuit have been investiated and the ane is as below. Satisyin ZCT condition x x 0-6 C Z Fi..(a).ZCS Boost convete Gain Vs. Nomalized switchin fequency Chaacteistics. o Ro Q.(4) f Resonant fequency, f f Resonat nducto, s ns Zo (5) Re sonatcapacito, C ZO..(6) And minimum and maximum Duty fo the auxiliay switch can be obtained as 0. to 0.. V. Fi..b.Resonant tank cicuit elements fo satisfyin ZCT condition Simulation And Expeimental Results A 0 Watt pototype FZCTBC system has been desined to veify the effectiveness of the soft-switchin/zct pefomance of the poposed convete and its contolle eulation capability. The convete is supplied fom a battey of V and the desied load voltae is 4 V. The paametes of the desined convete to meet the specifications ( <0% <5%) ae: =50 µh, =50 µh, =0.6 µh, C=70 nf, C=00 µf, C=00 µf, R= 9. Ω, fs = 00 khz. Zeo-cuent tansition/ soft-switchin pefomance of the poposed boost convete is veified thouh PSM simulations [0] and fo illustation pupose steady-state cuent and voltae wavefoms of main/ auxiliay switch/ diode SM/ SA and DM/ DA ae shown in Fis..(a) to.(d). t is clea fom these wavefoms that the main and auxiliay switches ae tunin-off only afte thei dain to souce Cuent is doppin to zeo, i.e ZCT tun-off. Futhemoe, the main diode and auxiliay diode ae tunin- ON at zeo voltae switchin (ZVS). n ode to veify the simulation esults a -to- 4 V, 0 W laboatoy pototype, convete paametes listed above, has been desined. The devices used in the pototype convete cicuit ae: Switch RFP50N, Diode MUR50, Dive cicuit R0 and Optoisolato-6N7. Fo nominal/ exteme conditions of duty atio the convete ZCT pefomance has been veified. To demonstate this ZCT featue, a V supply is connected to souce and then vaious cuents / voltae wavefoms have been ecoded. Soft-switchin ON-OFF tansition unde zeo cuent tun-off of the switchin devices (SA and SM) while zeo-cuent tun-off of the diodes (DA and DM) as shown in Fis. 4b and 5b. 06, RJET mpact Facto value: 4.45 SO 900:008 Cetified Jounal Pae 0

6 ntenational Reseach Jounal of Enineein and Technoloy (RJET) e-ssn: lume: 0 ssue: 05 May-06 p-ssn: Fi. 4.(c) Zeo ltae tun-on of the main diode. Fi. 4.(a) Zeo-Cuent tun OFF of the main switch. Fi. 4.(d) Zeo ltae tun-on and Zeo Cuent tun OFF of the main diode. Fi. 4.(b) Zeo-Cuent tun OFF of the main switch. V. Conclusion n this pape a soft-switchin fouth ode boost convete opeatin modes have been established and then zeo-cuent tun-off of main switch/aux. switch and zeo-cuent tun- OFF of diodes wee veified. FZCTBC has been desined fo and its validity is veified both in simulation and expeiment. Theoetical analysis esults wee in close aeement with the expeimental measuements. 06, RJET mpact Facto value: 4.45 SO 900:008 Cetified Jounal Pae 0

7 ntenational Reseach Jounal of Enineein and Technoloy (RJET) e-ssn: lume: 0 ssue: 05 May-06 p-ssn: Refeences [] Guichao Hua, Eic X. Yan, Yimin Jian, and Fed C. ee, Novel Zeo-cuent-tansition PWM Convetes, /9$0.00 Q 99 EEE. [] Mummadi Veeachay, Diital Contolle Desin fo Fouth-Ode Boost Convete, // 0 EEE. [] K. H. iu and F. C. ee, Zeo-voltae switchin technique in DC/DC convetes, EEE Tans. Powe Electon., vol. 5, pp. 9 04, July990. [4] G. Hua, C. S. eu,y. Jian, and F. C. ee, Novel zeo-voltae-tansition PWM convetes, EEE Tans. Powe Electon., vol. 9, pp. 9,Ma [5] Han-Seok Choi,Bo Hyun Cho, Novel zeocuent-switchin (ZCS) PWM switch cell minimizin additional conduction loss, EEE tansactions on ndustial Electonics, vol. 49, no., Febuay 005 [6] K. Wan, F. C. ee, G. Hua, and D. Boojevic, A compaative study of switchin losses of GBT s unde had-switchin, zeo-voltae-switchin and zeo-cuent switchin, in Poc. EEE PESC 94, 994, pp [7] K. Wan, G. Hua, and F. C. ee, Analysis, desin and ZCS-PWM boost convetes, in Poc. EEJ nt. Powe Electonics Conf., 995, pp [8] Powe Electonic Cicuits. By---ssa Bataseh. [9] MATAB, use manual, 005. [0] PSM, use manual, 005. [] dspc0f00, Micochip, use manual, , RJET mpact Facto value: 4.45 SO 900:008 Cetified Jounal Pae 04