Series Resonant Converter with Series-Parallel Transformers for High Input Voltage Applications
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Transcript of Series Resonant Converter with Series-Parallel Transformers for High Input Voltage Applications
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Series Resonant Converter with Series-Parallel Transformers for High Input Voltage Applications
C-H Chien1,B-R Lin2,and Y-H Wang1
1 Institute of Microelectronics, Department of Electrical Engineering, National Cheng-Kung University, Tainan 701, Taiwan
2 Department of Electrical Engineering, National Yunlin University of Science and Technology, Yunlin 640, Taiwan
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Outline
Introduction Circuit configuration Experimental results Conclusion
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Introduction
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For 3-phase 380V (or 480V) AC/DC converters the DC bus voltage > 500V (or 650V)
∴ select suitable power MOSFETs → difficult 3 level neutral-point clamp converter → overcome these drawbacks
more power switches more circuit components high cost complicated control schemes split capacitors and clamp diodes
the Vstress of MOSFETs → ½ DC bus voltage
What’s for in this study?
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What’s new in this study? A novel DC/DC converter (24V/40A, 960W)
2 circuit modules for high voltage application 2 capacitors and 2 half-bridge
series in high Voltage clamp the Vstress of MOSFET
Vstress = ½ input V
interleaved switching signal→ phase-shift ¼ switching T → 90° reduce ripple current (input and output) share the load current reduce the size of magnetic core
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Why is the topology ?
A series resonant tank high conversion efficiency high power density 2 series Transformers
balance the 2 winding current all semiconductors soft switching
switching loss ↓ ∵ (ZVS & ZCS)
wide input voltage and load 480V~600V all load
2 windings in parallel Istress ↓
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Circuit configuration
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Circuit configuration and key waveforms
Key waveforms Circuit configuration
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Different modes during 1 period
Mode 1
Mode 2
Mode 3
Mode 4
Mode 5
Mode 6
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Mode 1 ( t0≦t < t1 ) S1 off , S2 → off
VLm1=nVo= VLm2
Cs1, Cs2, and Lr1 → resonant iLr1
Cs2 => from 0 V → Vin/2 → charge Cs1 => from Vin/2 → 0 V → discharge
iLm1 → iLm2 → iD1 → iD3 →
mmmm
LmLm LLLL
ttnVtiti
21
00022 ,
)()()(
))()(()( 111 titinti LmLrD
))()(()( 213 titinti LmLrD
s
p
m
LmLmn
nn
L
ttnVtiti
,
)()()( 00
011
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Mode 2 ( t1≦t < t2 ) S2 off , S1 → ZVS→ on
iLm1= iLm2= iLr1 → mode end VLm1=nVo= VLm2
Cr1 and Lr1 → resonant applied voltage = (Vin/2 - 2nV0)
iLm1 ,iLm2 linearly ↑ slope = nV0/Lm
iLr1 → Vcr1→
)(cos)()(sin)(22/
)( 111111
1 tttittZ
tvnVVti rLrr
r
croinLr
)(sin)()(cos)](2/[22/)( 1111111 ttZtitttVnVVnVVtV rrLrrcroinoinCr
1
1
11
, 1
r
rr
rr
r C
LZ
CL
12
Mode 3 ( t2≦t < t3 ) S2 off , S1 → on → off
iLm1= iLm2= iLr1 → mode start S1 off → mode end iD1=iD2=iD3=iD4=0 Cr1, Lr1, Lm1, and Lm2 → resonant iLr1 →
Vcr1 →
)(cos)()(sin)(2/
)( 221221
1 tttittZ
tvVti pLrp
p
crinLr
)(sin)()(cos)](2
[2
)( 2212211 ttZtitttVVV
tV ppLrpcrinin
Cr
1
211
1211
)( ,
)(
1
r
mmrr
rmmr
p C
LLLZ
CLLL
13
Mode 4 ( t3≦t < t4 ) S2 off , S1 → off
VLm1=-nVo= VLm2 Cs1, Cs2, and Lr1 → resonant iLr1
Cs1 => from 0 V → Vin/2 → charge Cs2 => from Vin/2 → 0 V → discharge
iLm1 ,iLm2 linearly ↓ slope = -nV0/Lm
Vcs1 → Vcs2 → iD2 →
iD4 →
))()(()( 112 titinti LrLmD
))()(()( 214 titinti LrLmD
2133
1 ),(2
)()( 1
ssss
Lcs CCCtt
C
titV r
)(2
)(
2)( 3
32
1 ttC
tiVtV
s
Lincs
r
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Mode 5 ( t4≦t < t5 ) S1 off , S2 → ZVS → on
iLm1= iLm2= iLr1 → mode end VLm1=-nVo= VLm2
Cr1 and Lr1 → resonant applied voltage = 2nV0
iLm1 ,iLm2 linearly ↓ slope = -nV0/Lm
iLr1 → Vcr1→
)(cos)()(sin)(2
)( 441441
1 tttittZ
tvnVti rLrr
r
croLr
)(sin)()(cos)](2[2)( 4414411 ttZtitttVnVnVtV rrLrrcrooCr
1
1
11
, 1
r
rr
rr
r C
LZ
CL
15
Mode 6 ( t5≦t < t0 ) S1 off , S2 → on → off
iLm1= iLm2= iLr1 → mode start S2 off → mode end iD1=iD2=iD3=iD4=0 Cr1, Lr1, Lm1, and Lm2 → resonant iLr1 →
Vcr1 →
)(cos)()(sin)(
)( 551551
1 tttittZ
tvti pLrp
p
crLr
)(sin)()(cos)()( 5515511 ttZtitttVtV ppLrpcrCr
1
211
1211
)( ,
)(
1
r
mmrr
rmmr
p C
LLLZ
CLLL
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Key circuit parameters of the prototype circuit
Input voltage Vin → 480V ~ 600V Input nominal Vin,norm → 530V Output voltage Vo and current Io → 24V / 40A Series resonant frequency fr → 100kHz Switches S1~S4 → IRFP460 Diodes D1~D8 → MBR3060PT Turns ratio of T1~T4 → np:ns1:ns2=20:6:6 Resonant inductances Lr1~ Lr2 → 21 μH Magnetizing inductances Lm1~ Lm4 → 82 μH Resonant capacitances Cin1~ Cin2 → 330 μF/400V Output capacitances Co → 2200 μF/50V
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Experimental results
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The interleaved signals of switches
Experimental waveforms of gate voltages
S1~S4 at full load Vin=530V
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The ZVS of switches under input 530V
Experimental gate V, drain V and drain I of switch S1
Vin → 530V load → 25%
Experimental gate V, drain V and drain I of switch S1
Vin → 530V load → 100%
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The ZCS of rectifier diodes under input 530V
Measured waveforms of gate voltages vS1,gs and vS3,gs
Output currents of each center tapped rectifier at full load nominal input voltage
Vin=530V turn off
ZCS
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Switching Frequency VS. Output Power
Measured switching frequencies at different input
voltages at different load
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Conclusion
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A resonant converter with the series half-bridge legs for high DC bus voltage application
Two circuit modules share the load power
For each module series-connected in primary side parallel-connected in secondary side power MOSFETs → turn on ZVS rectifier diodes → turn off ZCS
Conclusion
switching loss↓
balance 2 winding current
share the load current
The voltage stress of each switch=0.5Vin
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Thanks for your attention!