three-level converters – a new approach for high voltage ...ruanxb.nuaa.edu.cn/home/ruan...
TRANSCRIPT
2012-12-10 1
Three-Level Converters – A New Approach for High Voltage and High Power DC-DC Conversions
Presented by
Xinbo Ruan
College of Electrical and Electronic EngineeringHuazhong University of Science and Technology
2012-12-10 2
Outlines
1. Backgrounds
2. Derivation of a Family of Three-Level Converters
3. Improved and Simplified Three-Level Converters
4. Buck TL Converter
5. ZVZCS PWM Hybrid Full-Bridge Three-Level
Converter
6. Possible of Three-Level Voltage
7. Conclusions
2012-12-10 3
Outlines
1. Backgrounds
2. Derivation of a Family of Three-Level Converters
3. Improved and Simplified Three-Level Converters
4. Buck TL Converter
5. ZVZCS PWM Hybrid Full-Bridge Three-Level
Converter
6. Possible of Three-Level Voltage
7. Conclusions
2012-12-10 4
Vin
D1
D2
AB
Cd2
Q3
Q4
D3
D4
D6
Tr
DR1
DR2
Q1
Q2
Cd1D5
Lf
Cf
RLd
Vo
+
-
C
D
3-phase 380V±20% ac input is rectified
to a dc voltage:
w/o PFC: Vdcmax = 630V
with PFC: Vdc = 800-1000V
Backgrounds
Three-Level Converter
☺ The voltage stress of the power
switch is half of the input voltage.
In order to reduce the voltage stress of the switches
2012-12-10 5
Vin
D1
D2
AB
Cd2
Q3
Q4
D3
D4
D6
Tr
DR1
DR2
Q1
Q2
Cd1D5
Lf
Cf
RLd
Vo
+
-
C
D
- The voltage stress of the switches is the half of the input voltage;
- It is attractive for high voltage and high power dc/dc conversions
Vin
D1
D2
AB
Cd2
Q3
Q4
D3
D4
Tr
DR1
DR2
Q1
Q2
Cd1Lf
Cf
RLd
Vo
+
-
C
DVin
D1
AB
Cd2 Q2 D2
Tr
DR1
DR2
Q1Cd1
Lf
Cf
RLd
Vo
+
-
C
D
Derivation of Half-Bridge TL Converter
2012-12-10 6
Motivation
Extend the derivation of Half-Bridge Three-Level
converter to all the DC-DC converters
To reduce the voltage stress
of the switches.
2012-12-10 7
Outlines
1. Backgrounds
2. Derivation of a Family of Three-Level Converters
3. Improved and Simplified Three-Level Converters
4. Buck TL Converter
5. ZVZCS PWM Hybrid Full-Bridge Three-Level
Converter
6. Possible of Three-Level Voltage
7. Conclusions
2012-12-10 8
TL Switch Cells
Vin
D1
D2
AB
Cd2
Q3
Q4
D3
D4
D6
Tr
DR1
DR2
Q1
Q2
Cd1D5
Lf
Cf
RLd
Vo
+
-
C
D
Q1
Q2
Dc
a
bc
Vcl /2
Vcl /2
Anode Cell
Q1
Q2
Dc
a
b
c
Vcl /2
Vcl /2
Cathode Cell
- Two series switches;- Clamping voltage source splitting
into two equally;- Clamping diode.
2012-12-10 9
Derivation of Buck TL Converter
Lf
Vin Cf
RLd
Vo
+
-D1
Q Lf
Vin Cf
RLd
Vo
+
-D1
Q1 Q2
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D1
Q1 Q2Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D1Dc
Q1 Q2
2012-12-10 10
A Family of TL Converters
BuckBoost
Buck/Boost Cuk
Sepic Zeta
2012-12-10 11
A Family of TL Converters
Forward Flyback
Push-Pull
2012-12-10 12
Full-Bridge
Half-Bridge
A Family of TL Converters
Vin
D1
D2
AB
Cd2
Q3
Q4
D3
D4
Dc2
TrDR1
DR2
Q1
Q2
Cd1
Dc1
Lf
Cf
RLd
Vo
+
-*
**
2012-12-10 13
Outlines
1. Backgrounds
2. Derivation of a Family of Three-Level Converters
3. Improved and Simplified Three-Level Converters
4. Buck TL Converter
5. ZVZCS PWM Hybrid Full-Bridge Three-Level
Converter
6. Possible of Three-Level Voltage
7. Conclusions
2012-12-10 14
Output Waveform
v
0
VinVo
Vin /2
t
v
0
VinVo
t
Lf
Vin Cf
RLd
Vo
+
-D1
Q Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D1Dc
Q1 Q2
Buck Converter Buck TL Converter
2012-12-10 15
Problems of Buck TL Converter
v
0
VinVo
Vin /2
t
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D1Dc
Q1 Q2
VinCd2
Cd1
Cf
RLd
Vo
+
-D1Dc
Q1 Q2Cd2 provides moreenergy, which results in unbalance of voltage of the input divided capacitors
2012-12-10 16
D2
Q2
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
Q4
v
0
VinVo
Vin /2
t
D2
Q2
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
Q4
Cd1 provides moreenergy, which results in unbalance of voltage of the input divided capacitors
D2
Q2
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
Q4
Problems of Buck TL Converter
2012-12-10 17
Combined Buck TL Converter
D2
Q2
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
Q4
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D1Dc
Q1 Q2
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
D1
Q1
Q2
D2
Q3
Q4B
A
2012-12-10 18
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
D1
Q1
Q2
D2
Q3
Q4B
A
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
D1
Q1
Q2
D2
Q3
Q4B
A
vAB
0
t
Q2
Q1
Vo
Vin /2
t
t
Vin
t
t
Q3
Q4
Ts 3Ts' '2Ts'
Ts Ts
4Ts'
The voltage of the divided capacitors are Balanced.
Combined Buck TL Converter
2012-12-10 19
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
Improved Buck TL Converter
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
D1
Q1
Q2
D2
Q3
Q4B
A
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-D3
D1
Q1
Q2
D2
B
A
vAB
0
t
Q2
Q1
Vo
Vin /2
t
t
Vin
t
t
Q3
Q4
Ts 3Ts' '2Ts'
Ts Ts
4Ts'
2012-12-10 20
vAB
0
t
Q2
Q1
Vo
Vin /2
t
t
Vin
t
t
Q3
Q4
Ts 3Ts' '2Ts'
Ts Ts
4Ts'
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
vAB
0
t
Q2
Q1
Vo
Vin /2
t
t
Vin
t
t
Q3
Q4
Ts 3Ts' '2Ts'
Ts Ts
4Ts'
1. The voltage of the divided capacitors are balanced;
2. The ripple frequency of vAB is twice the switching frequency;
3. Q1 and Q2 are interleaving switched.
Improved Buck TL Converter
2012-12-10 21
Improved TL Converters
Lf
Cf
RLd
Vo
+
-
D1
D2
Q2
VinCd2
Cd1
Q1
Lb
Vin
Cf1
RLd
Vo
+
_
D1
D2
Q1
Q2Cf2
BuckBoost
Buck/Boost Cuk
Sepic
LfCf1
RLd
Vo
_
+
D1
D2Q2
VinCd2
Cd1
Cf2
Q1
L1
Vin
Q1
Q2
Cb1
Cb2
Cf1
RLd
Vo
+
_
D1
D2
Cf2
L2 L1
Q2
VinCd2
Cd1
Q1
Cf
RLd
Vo
+
-
D1
D2
Cb1
Cb2
Zeta
2012-12-10 22
Simplified Forward TL Converter
Vin
Q1
**
Q2
*
Tr1
DR1 RLd
Vo
+
-
Lf
DFW
D1Dc
Vin
Q1
*
Q2
*
Tr1
DR1RLd
Vo
+
-
Lf
DFW
D1
D2
A
Vin
Q1
**
Q2
*
Tr1
DR1 RLd
Vo
+
-
Lf
DFW
D1Dc
Vin
Q1
**
Q2
*
Tr1
DR1 RLd
Vo
+
-
Lf
DFW
D1
Dc
Q1 and Q2 conduct Q1 on, Q2 off
Q1 off, Q2 off
2012-12-10 23*
Q1 Q2
D1Cd1
Cd2
TrVin
Derivation of Hybrid Full-Bridge TL Converter
*
Q3 Q4
D2
Cd1
Cd2
TrVin
Cd1Q1
Cd2
D7
D8Vin
Q5
Q6
Q2
Q3
Q4
A
B
Tr
*
2012-12-10 24
Outlines
1. Backgrounds
2. Derivation of a Family of Three-Level Converters
3. Improved and Simplified Three-Level Converters
4. Buck TL Converter
5. ZVZCS PWM Hybrid Full-Bridge Three-Level
Converter
6. Possible of Three-Level Voltage
7. Conclusions
2012-12-10 25
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_3L
ILfmax_3L
Vin/2
Vin
ToffTon
t
t
t
0
Ts
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_2L
ILfmax_2L
Vin/2
ToffTon
t
t
t
0
Ts
Key Waveforms
D > 0.5 D < 0.5
2012-12-10 26
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_3L
ILfmax_3L
Vin/2
Vin
ToffTon
t
t
t
0
Ts
D > 0.5
Operation of Buck TL Converter: D>0.5 (1)
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
2012-12-10 27
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_3L
ILfmax_3L
Vin/2
Vin
ToffTon
t
t
t
0
Ts
D > 0.5
Operation of Buck TL Converter: D>0.5 (2)
2012-12-10 28
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_3L
ILfmax_3L
Vin/2
Vin
ToffTon
t
t
t
0
Ts
D > 0.5
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
Operation of Buck TL Converter: D>0.5 (3)
2012-12-10 29
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_3L
ILfmax_3L
Vin/2
Vin
ToffTon
t
t
t
0
Ts
D > 0.5
Operation of Buck TL Converter: D>0.5 (4)
2012-12-10 30
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_2L
ILfmax_2L
Vin/2
ToffTon
t
t
t
0
Ts
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
D < 0.5
Operation of Buck TL Converter: D<0.5 (1)
2012-12-10 31
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_2L
ILfmax_2L
Vin/2
ToffTon
t
t
t
0
Ts
D < 0.5
Operation of Buck TL Converter: D<0.5 (2)
2012-12-10 32
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_2L
ILfmax_2L
Vin/2
ToffTon
t
t
t
0
Ts
D < 0.5
Operation of Buck TL Converter: D<0.5 (3)
2012-12-10 33
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_2L
ILfmax_2L
Vin/2
ToffTon
t
t
t
0
Ts
D < 0.5
Operation of Buck TL Converter: D<0.5 (4)
2012-12-10 34
1.0
0.8
0.6
Vo / Vin
A
D=1.0
D=0.9
D=0.7
D=0.8
D=0.6
D=0.5
AD=0.4
D=0.2
D=0.3
D=0.1
D=0.0
0.2
0.4
0.01.0 2.0 Io / IoGmax
Voltage Conversion Ratio
Vo / Vin = D
2012-12-10 35
Output Filter Inductance
The output inductance of Buck TL converter
reduces to 1/4 ofthat of Basic Buck converter
*_Lf BuckIΔ
*_ _Lf Buck TLIΔ
2012-12-10 36
Output Filter Capacitor
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_3L
ILfmax_3L
Vin/2
Vin
ToffTon
t
t
t
0
Ts
The output capacitor in Buck TL
converter reduces to 1/2 of that in Basic Buck converter
2012-12-10 37
Q2
iLf
Q1
vAB
t0 t1 t2 t3 t4
t
IoILfmin_3L
ILfmax_3L
Vin/2
Vin
ToffTon
t
t
t
0
Ts
Unbalanced capacitor voltage
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
ASlight difference of 1) control signal and 2) drive circuit
Slight difference of duty cycle of the two switches
Unbalanced voltage of the divided capacitors
2012-12-10 38
Divided Capacitor Voltage Sharing
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
Kf_in
infK _21
Opti-Isolated
Kf_vo
-1_
+Kp
PI
_
+Vref
Comp_1
Comp_2
Q1
Q2
2012-12-10 39
Experimental Results
vDS(Q1):[100V/div]
vDS(Q2):[100V/div]
vAB:[100V/div]
Time:[5us/div]
vDS(Q1):[100V/div]
vDS(Q2):[100V/div]
vAB:[100V/div]
Time:[5us/div]
Without Feed-Forward control With Feed-Forward control
2012-12-10 40
vDS(Q1):[100V/div]
vDS(Q2):[100V/div]
vAB:[100V/div]
Time:[5us/div]
iLf:[5A/div]
vDS(Q1):[100V/div]
vDS(Q2):[100V/div]
vAB:[100V/div]
Time:[5us/div]
iLf:[5A/div]
D > 0.5 D < 0.5
Experimental Results
2012-12-10 41
Outlines
1. Backgrounds
2. Derivation of a Family of Three-Level Converters
3. Improved and Simplified Three-Level Converters
4. Buck TL Converter
5. ZVZCS PWM Hybrid Full-Bridge Three-Level
Converter
6. Possible of Three-Level Voltage
7. Conclusions
2012-12-10 42
ZVZCS PWM Hybrid Full-Bridge TL Converter
2012-12-10 43
Main Circuit and Key Waveforms
Vcbp
Vcbp
I I Kp o0 = /
t
t
t
t
t
t
Q1 Q1Q4
Q2 Q2Q3
Q6 Q6Q5
vAB Vin
Vin
Vin/2Vin/2
t
Vin/2KVin/K
t0 t1 t2 t3 t4 t5 t7t6 t8 t10t9 t14t13t12t11
ip
vcb
vrect
Treset
2012-12-10 44
The Secondary Rectified Voltage
t
vrect
0Ton
Ts/2
Vin/KVo
t
vrect
0Ton Treset
Ts/2
Vin/2K
Vin/KVo
Full-Bridge Converter Full-Bridge Three-Level Converter
2012-12-10 45
424 477 530 583 6362
4
6
8
10
12
Input Voltage (V)
Lf (u
H)
Lf_FB Vin( )
Lf_hybrid Vin( )
Vin
The Filter Inductance
Full-Bridge Converter
Full-Bridge Three-Level Converter
2012-12-10 46
Parameters for Prototype Converter
-Vin=530VDC (rectified and filtered from 3 phase 380VAC/50Hz)
-Vo = 54 VDC;- Io = 50 A;- Q1(D1&C1) - Q4(D4&C4): IRF460;- Q5 and Q6: CT60AM-20;- D5 - D8: DSEI30-06A;- Rectifier diode: MEK95-06 DA;- Ratio of windings : K=19:3;- Leakage inductance Llk=6uH; - Blocking capacitor: Cb=1uF; - Output filter inductance Lf=6uH; - Output filter capacitor Cf=6600uF; - Switching frequency: fs=50kHz.
2012-12-10 47
Experimental Results
vAB: [1000V/div]
vcb: [100V/div]
ip: [20A/div]
Time: [5us/div]
vrect: [50V/div]
iD (Q1): [5A/div]
vGS (Q1): [25V/div]
Time: [2us/div]
vDS (Q1): [250V/div]
ZVS for Chopping Switches
ZV turn-on ZV turn-off
ip reduce to zero
2012-12-10 48
ZVS for lagging SwitchesZVS for leading Switches
iD (Q2): [5A/div]
vGS (Q2): [25V/div]
Time: [2us/div]
vDS (Q2): [250V/div]
ic (Q6): [5A/div]
vBE (Q6): [25V/div]
Time: [2us/div]
vCE (Q6): [500V/div]
Zero-Currentturn-off
Zero-Current turn-onZV turn-on ZV turn-off
Experimental Results
2012-12-10 49
vAB: [1000V/div]
vcb: [100V/div]
ip: [20A/div]
Time: [5us/div]
vrect: [50V/div]
vAB: [500V/div]
vcb: [100V/div]
ip: [20A/div]
Time: [5us/div]
vrect: [50V/div]
Two-Level ModeThree-Level Mode
Experimental Results
2012-12-10 50
Conversion Efficiency
87
89
91
93
95
0 10 20 30 40 50Output current (A)
Effic
ienc
y (%
)
2012-12-10 51
Conversion Efficiency
290 320 350 380 410 440 470Input voltage (V)
Effic
ienc
y (%
)
93.0
93.2
93.4
93.6
93.8
94.0
94.2
2012-12-10 52
Several ZVZCS Hybrid FB TL Converters
Cb
Cd1Q1 D1
C1
Css
Cd2
D7
D8
Q2 D2C2
Q3 D3C3
Q4 D4C4
A
Tr
Llk
*
Ls
DR2
DR1Lf
Cf
RLd
*
*
Q6
B
D6
Q5 D5
Qb
Cd1Q1 D1
C1
Css
Cd2
D7
D8Vin
Q2 D2C2
Q3 D3C3
Q4 D4C4
A
TrDR1
Llk
*
DR2
*
*
Lf
Cf
Cb
Db
RLd
Q6
B
D6
Q5 D5
2012-12-10 53
Cd1Q1 D1
C1
Css
Cd2
D7
D8Vin
Q2 D2C2
Q3 D3C3
Q4 D4C4
A
TrDR1
Lf RLd
Llk
*
DR2
Cb1
Db2
Db1
Cf
*
*
Q6
B
D6
Q5 D5
Cb1 Db2
Db1Cb2
Db3
Lf
Cf
RLd
Cd1Q1 D1
C1
Css
Cd2
D7
D8Vin
Q2 D2C2
Q3 D3C3
Q4 D4C4
A
TrDR1
Llk
*
DR2
*
*
Q6
B
D6
Q5 D5
Several ZVZCS Hybrid FB TL Converters
2012-12-10 54
Outlines
1. Backgrounds
2. Derivation of a Family of Three-Level Converters
3. Improved and Simplified Three-Level Converters
4. Buck TL Converter
5. ZVZCS PWM Hybrid Full-Bridge Three-Level
Converter
6. Possible of Three-Level Voltage
7. Conclusions
2012-12-10 55
Availability of Three-Level Voltage Waveforms
Lf
VinCd2
Cd1
Cf
RLd
Vo
+
-
D1
Q1
Q2
D2
B
A
In order to achieve three-level voltage waveform, 1) there should be two divided capacitors. 2) The two divided capacitors could power the load simultaneously or alternatively.
vAB = Vin, Vin/2 and 0
2012-12-10 56
Possibility of Three-Level Voltage Waveforms
Lf
Cf
RLd
Vo
+
-
D1
D2
Q2
VinCd2
Cd1
Q1
Lb
Vin
Cf1
RLd
Vo
+
_
D1
D2
Q1
Q2Cf2
BuckBoost
Buck/Boost Cuk
Sepic
LfCf1
RLd
Vo
_
+
D1
D2Q2
VinCd2
Cd1
Cf2
Q1
L1
Vin
Q1
Q2
Cb1
Cb2
Cf1
RLd
Vo
+
_
D1
D2
Cf2
L2 L1
Q2
VinCd2
Cd1
Q1
Cf
RLd
Vo
+
-
D1
D2
Cb1
Cb2
Zeta
Non-isolated TL Converters
2012-12-10 57
Possibility of Three-Level Voltage Waveforms
Vin
D1
D2A
B
Cd2
Q3
Q4
D3
D4
D10
Q1
Q2
Cd1D9
D5
D6
Q7
Q8
D7
D8
D12
Q5
Q6D11
Tr
DR1
DR2
Lf
Cf
RLd
Vo
+
_
C
D
**
*
FB TL Converter
H-FB TL Converter
2012-12-10 58
Possibility of Three-Level Voltage Waveforms
Vin
DR2
TrDR1
* *
**
Q1
Q3
Q2
Q4
D1
D2
D3
D4D6
D5
RLd
Vo
+
_
Lf
Cf
Flyback TL Converter
HB TL Converter
Forward TL Converter
Push-Pull TL Converter
2012-12-10 59
Conclusions
1. Three-Level Converters- A-TLSC and C-TLSC are extracted;- A family of TL converters are proposed;- The non-isolated TL converters are improved;- Forward TL converter is further simplified;- A hybrid FB TL converter are proposed.
2. The advantages of the TL converters- Reduction of the voltage stress of the switches;- some TL converters obtain TL waveform, which can
significantly reduce the filter.
3. Method to ensure the voltage sharing of the divided capacitorsis proposed.
2012-12-10 60
Thanks for your attention!
Q/A