Professor Omar Hegazy, MOBI at VUB's talk at the EV Momentum Summit Berlin, 19 June 2018

1. Advances in Power Electronics
Converters for Efficient Drivetrains
1
By Prof. Dr. Omar Hegazy
ü Professor and Team leader of Power Electronics
and Electrical Machines

2. Outline
q Introduction of Power Electronics Systems
q Integrated converter design and performances
qNew switching technologies: WBG
q Conclusions and Future trend
2

3. Outline
q Introduction of Power Electronics Systems
q Integrated converter design and performances
qNew switching technologies: WBG
q Conclusions and Future trend
3

4. 4
How to change the way we
Design technologies?
Thinking in full systems & large scale
1) Material/component development (power electronics, chargers
Battery, motor efficiency, material criticality)
2) Co-design of powertrain systems (sizing, modularity)
3) Integration and thermal management
4) Charging strategy optimization (grid integration, V2X)
5) Designing the full technosphere (supply chain mgt, circular economy)
Systemlevel
Technology
Integration
Large scale

5. Powertrain Topologies: BEVs (/SC)
5
Advantages of Battery (High Energy) /SC or
High Power Battery
ü Improve the battery lifetime
ü More energy efficiency
ü High dynamic performance
ü Advanced DC/DC converter (i.e. MPC) with high
efficiency (up to 96% thanks to WBG technology)
o More compactness
o High reliability
-
+
Inverter
DC/AC
Electric motor
DC
Link
Uni/Bi-directional
dc-dc converter
Battery
SC
-
+
Bi-directional
dc-dc converter
HE
-
+
Inverter DC/AC
Electric motorBi-directional
dc-dc converter
BatterySC
-
+
HE
-
+
Inverter
DC/AC
Electric motor
DC
Link
Multiple-input
Bidirectional
dc-dc converter
Battery
SC
-
+
HE
-
+
Inverter
DC/AC
Electric motor
DC
Link
Uni/Bi-directional
dc-dc converter
Battery
SC
-
+
Bi-directional
dc-dc converter
HP
HE: High Energy ; HP: High power: WBG: Wide-Bandgap semiconductors

6. Advances in Charging Systems
6
Charging Systems
Conductive
On-Board Off-Board
Inductive
(Wireless)
On-board (Secondary Coil) &
Off-Board (Primary Coil)
OLEV
WPT Up to
100 kW
Up to 600 kWUp to 100 kW
Up to 22 kW

7. Outline
q Introduction of Power Electronics Systems
q Integrated converter design and performances
qNew switching technologies: WBG
q Conclusions and Future trend
7

8. 8
New Switching technologies: Wide
Bandgap (WBG) à SiC & GaN
Source: a Fairchild Sem iconductor presentation by Alex AVRON, founder of PntPower.comSource: status of Power Electronics Industry report, Yole Développem ent, 2017

9. 9
New Switching technologies: WBG
Source: a Fairchild Sem iconductor presentation by Alex AVRON, founder of PntPower.comSource: status of Power Electronics Industry report, Yole Développem ent, 2017

10. Outline
q Introduction of Power Electronics Systems
q Integrated converter design and performances
qNew switching technologies: WBG
q Conclusions and Future trend
10

11. 11
Integrated Power Electronics Converters:
MPC for multi-source
Battery
+
-
Q2
L1
L2
L3
Q4 Q6
Cf
Electric motor
Inverter
DC/AC
Q1 Q3 Q5
Q2
L1
L2
L3
Q4 Q6
Q1 Q3 Q5
SC
+
-
EMTECHNO project

12. 12
g
d
Core
database
IGBT
database
Multiobjective
Optimization
Genetic Algorithm
Pareto-front
& Ranking method
SOLIDWORKS Matlab
Computer-Aided Design
FEM Inventor
Optimization Problem
Formulation
Litz wire
database
Converter Analysis &
Control design
Prototype Design
DatabaseOptimized Design
Solver
Specification
(Pmax, Vin, Vout, Iripple)
Integrated Power Electronics Converters:
MPC Optimization
Objective functions of Optimization
ü Input current ripples
ü Weight of inductor
ü Power loss of converter
EMTECHNO project

13. 13
Integrated Power Electronics Converters:
MPC control system
Battery
+
-
Q2
L1
L2
L3
Q4 Q6
Cf
Electric motor
Inverter
DC/AC
Q1 Q3 Q5
Q2
L1
L2
L3
Q4 Q6
Q1 Q3 Q5
SC
+
-
EMTECHNO project

14. 14
Integrated Power Electronics Converters:
MPC Optimization
IGBT modules/Heatsink thermal equivalent model
Battery
+
-
Q2
L1
L2
L3
Q4 Q6
Cf
Q1 Q3 Q5
Q2
L1
L2
L3
Q4 Q6
Q1 Q3 Q5
SC
+
-
Loss
Model Heat sink
Thermal
Model
Tsink
EMTECHNO project

15. 15
Impact of WBG switches on MPC performance
0
0.5
1
1.5
2
2.5
3
3.5
MPC
with Si
@ 20KHz
MPC
with SiC
@ 60KHz
PowerLosses(kW)
P_IGBT P_d P_core P_cond
Reduce
57%
Source: E. Gurpinar and A. Castellazzi, "Single-Phase T-Type
Inverter Performance Benchmark Using Si IGBTs, SiC
MOSFETs, and GaN HEMTs," in IEEE Transactions on Power
Electronics, vol. 31, no. 10, pp. 7148-7160, Oct. 2016.
Source: VUB
EMTECHNO project

16. 16
On-board Charger based on GaN Technology
Objectives
1. Architecture Optimization
2. Cost/Size Optimization
3. Advanced topologies
4. V2G Or G2V MODES
Bidirectional
AC-DC
Isolated-
Bidirectional
DC-DC
DC-link
Battery
Grid
Si Device
<100kHz
3-12W/in3
92-94%Efficiency
Uni-directional
Manuf.??
GaN Device
>250kHz
>20W/in3
95-96%Efficiency
Bidirectional
Target

17. 17
On-board Charger: Architecture Optimization and
Integration
DC/AC
3-Phase
Inverter
H
V
D
C
B
U
S
Bidirectional
DC/DC
Converter
Propulsion Battery
EM
Super Capacitor
Bidirectional
DC/DC
Converter
LDC
Converters
Auxiliary Battery
Off-Board
charger
On-Board
Charger
Integration

18. 18
On-board Charger: Architecture Optimization and
Integration
DC/AC
3-Phase
Inverter
H
V
D
C
B
U
S
Bidirectional
DC/DC
Converter
Propulsion Battery
EM
Super Capacitor
Bidirectional
DC/DC
Converter
LDC
Converters
Auxiliary Battery
Off-Board
charger
On-Board
Charger
Integration

19. 19
? Integration
Conventional OBC
Conventional LDC
Problems of Individual Power-Elec Converter in EVs
• Large number of components
• Less compactness
• Low power density
Advantages
• Compactness
• High power density
• Cost reduction
Challenges:
• Performances of the LDC
converter
OBC
LDC
MOBC
On-board Charger: Architecture Optimization and
Integration

20. On-board Charger: Architecture Optimization and
Integration
The proposed Multi-Functional OBC
ü 40% size reduction of the
LV DC/DC
ü Around 60 % reduction in
the cost of LV DC/DC
converter
üHigh compactness
ü97% efficiency

21. Outline
q Introduction of Power Electronics Systems
q Integrated converter design and performances
qNew switching technologies: WBG
q Conclusions and Future trend
21

22. Conclusions
22
ü Wide bandgap (WBG) technology has a high potential to
improve the converters’ performance towards:
ü High efficiency
ü More compactness
ü High reduction in the cooling system
üPower Electronics: design optimization framework is an enabler
tool toward minimum TCO and minimized development time.
üV2G mode towards smart mobile storage system

23. 23
Contacts
Prof. Omar Hegazy
Omar.hegazy@vub.be
+32 2 629 29 92
Thank you for your attention
Mobi.vub.ac.be/home/