Dual Flying-Capacitor Active Neutral-Point-Clamped (ANPC) Multilevel Inverter Arash Khoshkbar Sadigh, Penn State University Electric Power Industry Conference Oct. 2018 1
Power Electronics Lab
Outline: Background of Multilevel Inverter
Conventional Active Neutral Point Clamp
(ANPC) Converter Proposed Dual Flying Capacitor Multilevel
Inverter Simulation Results Experimental Results
Conclusion
2
Power Electronics Lab
Introduction of Multilevel Inverters: What is Multilevel Inverter? Why Multilevel Inverter? Vout
Why not Two-Level Inverters? E/2
IGBT voltage rating Sa EMI issue S
-E/2
a
Vout Safilter size Output
EE/2
E/4Switching loss Sa E
-E/4
E EE/2
VCE VCE1
Sa
E/2
3.3kV motor-E/2 drive
DC Link Voltage: 3.3kV*1.414=4.7kV
6.6kV motor drive
DC Link Voltage: 6.6kV*1.414=9.3kV VCE2
Sa
3
Use 6.5kV IGBT No IGBT exist Power Electronics Lab
Outline: Background of Multilevel Inverter
Conventional Active Neutral Point Clamp
(ANPC) Converter Proposed Dual Flying Capacitor Multilevel
Inverter Simulation Results Experimental Results
Conclusion
4
Power Electronics Lab
Conventional Active Neutral Point Clamp (ANPC) Converter:
ABB production: ACS2000, 250 – 3200 kW, 4.0 – 6.9 kV
Ref: ABB Brochure of ACS2000 5
Power Electronics Lab
Conventional Active Neutral Point Clamp (ANPC) Converter: LF IGBTs Pros:
HF IGBTs
One flying capacitor 2E E
Vdc
VA
0 -E -2E
:
Cons
Transient voltage imbalance Poor loss distribution
6
Power Electronics Lab
Outline: Background of Multilevel Inverter
Conventional Active Neutral Point Clamp
(ANPC) Converter Proposed Dual Flying Capacitor Multilevel
Inverter Simulation Results Experimental Results
Conclusion
7
Power Electronics Lab
Proposed Dual Flying Capacitor Multilevel Inverter: High Freq.
S1
+ -
E
S2 C1
+
S5 + E
Sʹ1
Vdc S3
+ E
+
Sʹ4
E
-
Sʹ3
2E
Sʹ2
E
iA Sʹ1 VA
Vdc
S6 +
S3
-
S4
VN
-E
S6 C2
+
S50 -2E
E
S4 C2
Line Freq.
S2 C1
Sʹ2
E
-
S1
+
E
iA V iB A V iC B VC
Sʹ4
E
-
Sʹ3
8
Power Electronics Lab
Dual Flying Capacitor Multilevel Inverter: Soft Commutation for proposed DFC-ANPC Converter Off switches
On switches
Off Off switches switches
State 0P
+2E +2E
SS22
S2S22
C C22
C2 -2E -2E
+2E +2E
S2
S3
C1
Sʹ Sʹ22
C11
SS33 SS66
Sʹ4
-2E
S66
VA
S2
SS33
0
S6
S4Sʹ44
C2
Sʹ33
Sʹ4
-2E
Sʹ2SS55 Sʹ1
S5 V VAA
SS66
C22
Sʹ3
Sʹ3
SS22
VAA 0
44
C2
S1
Sʹ Sʹ11
S5
S3S C22
SS11
C1 Sʹ Sʹ22
S55
S33
0
S6
Sʹ Sʹ33
Sʹ22
Sʹ1
SS44
Sʹ Sʹ44
C11
Sʹ11
VA
State 0N +2E+2E
Sʹ2
SS55 V VAA 0
S4
State 0N
State 00
S1S11
Sʹ1
Outbound current
State 00
State State 0P 0P
S115 Sʹ Sʹ
Outbound current
Inbound current
SS11
Sʹ2 00
On switches
S1 C C11
C1
Inbound current
SS44
S3
Sʹ Sʹ44
S4
Sʹ Sʹ33
Sʹ4
S6
Sʹ3
-2E
-2E 9
Power Electronics Lab
Dual Flying Capacitor Multilevel Inverter: High Freq.
Pros:
S1
+ E
-
S2 C1
+
S聞2
E
-
S聞1
+
S3
S5
Vdc S6
E
VN
S4 C2
+
ZVS for line freq. switches No transient voltage imbalance Better loss distribution
Line Freq.
iA V iB A V iC B VC
:
Cons
S聞4
One additional capacitor (but 1.4 times less rms current)
E
-
S聞3
10
Power Electronics Lab
Dual Flying Capacitor Multilevel Inverter: Sinusoidal Reference PSC for S 2
1
PSC for S 4
-1
M
PSC for S 1
0
Natural Balancing Active Balancing
PSC for S 3
S5 1
0 1
PWM 0 Modulation 1 0 1 0 1 0 1 0
VC1
S1
ix
S 2Cycle
Separation
S3
VC2
S4
Cycle change signal
ix S5
Active State Balancing Machine Algorithm Decoder
S1
Active State Balancing Machine Algorithm Decoder
S3
S2
S4 S6
S6 Overlap providing state 00 for soft cycle commutation
2E E 0
Phase shifted modulation.
-E -2E
11
Power Electronics Lab
Outline: Background of Multilevel Inverter
Conventional Active Neutral Point Clamp
(ANPC) Converter Proposed Dual Flying Capacitor Multilevel
Inverter Simulation Results
Experimental Results Conclusion
13
Power Electronics Lab
Simulation Results: VA
I V Simulation and Experiment Parameters 16 A
Circuit Parameter
0
0
Value
0
16 kV
-400
-16 Experiment DC-link Voltage ) VCA1 V VCB1 VCB2 (VVdc CC1 CA2
VB
IB
4.4 DC-link Capacitors (Cdc400 ) 4.2
Flying Capacitors (Cxx)200 4.0
4 0
0
3.8 Modulation Index Phase -200 (M)
-4
3.6
-8
1.6 mF
8
400 µF
0
1
-8
-400
Phase Fundamental Frequency -16 (fo) 10 I C
0
VC
20 Time (ms)
VCA
Voltage (kV)
Phase Switching Frequency (f s) 16 400
8
400 V
VCC2
VBC
16 Voltage (kV)
Voltage (kV)
8
Voltage (kV)
8
-200 Simulation DC-link Voltage (Vdc)-8
-4 -8
50 Hz
30
40
1.65 kHz
8 Load Inductance (Lload200 ) Flying Capacitors’ 0 0Voltages Load Resistance (Rload-200 )
Current (A)
Voltage (kV)
Voltage (kV)
200
4
Current (A)
400
Current (A)
Voltage (kV)
8
AB
4 0 -4 -8 0
10
30
40
0
Balance Booster Capacitance (Cboost)
Balance Booster Resistance (R boost) Phase Voltages & Currents
14
18 Ω
-8
-400 Balance Booster Inductance (Lboost -16 )
20 Time (ms)
15 mH
1.85 mH 10
20 Time (ms)
30
40
20 µF
1.5 Ω Line Voltages Power Electronics Lab
Experimental Results: Reconfigurable Multilevel Converter Platform IGBT Module
Control Unit
Diode Module
dc-link
Phase legs
Measurement Panel
Converter Platform
15
Power Electronics Lab
Experimental Results: Reconfigurable Multilevel Converter Platform Converter Platform
Measurement Devices
Power Supply
Inductor Bank
Back
Resistor Bank
Front
16
Balance Booster
Power Electronics Lab
Experimental Results:
Phase Voltages (100V/div) and Currents (5A/div) SteadyFlying stateLine Capacitors’ flying Voltages Capacitors’ Voltages (100V/div) Voltages (20V/div) (5V/div)
17
Power Electronics Lab
Experimental Results: M = 0.4
Conventional ANPC
M = 0.95
T max= 100째C
T max= 81.5째C
T max= 68.0째C
Proposed DFC-ANPC
T max= 95.5째C
18
Power Electronics Lab
Outline: Background of Multilevel Inverter
Conventional Active Neutral Point Clamp
(ANPC) Converter Proposed Dual Flying Capacitor Multilevel
Inverter Simulation Results Experimental Results
Conclusion
19
Power Electronics Lab
Conclusion: Application of proposed New multilevel inverter ismultilevel proposedinverter: Medium Extrafor flying capacitor voltage motor drive ZVS line frequency switches. times less rms Medium voltage grid current tied inverterfor line frequency No 1.4 transient voltage imbalance
switches. Solid state transformer Easier to be extended for higher number of levels.
Better power loss distribution. Lower junction temperature. Can provide more power with same switches. 20
Power Electronics Lab
22
Power Electronics Lab