Effective modeling of an EV Powertrain in Saber

1. Alan Courtay
October 29, 2015
Paris Saber Seminar, La Defense
Modeling of PMSM Motor Drive
Multi Time Scale Analysis with Saber

2. © 2015 Synopsys, Inc. 2
Simplified Electric Vehicle Powertrain
Modeled after Market Available Electric Vehicle
Published
PMSM Electric Motor Max power / torque: 80 kW / 280 Nm
Li-Ion Battery
Total energy: 24 kWh
Max power > 90 kW
Number of cells: 192 (2 parallel, 96 series)
Cell voltage: 3.8 V
Nominal system voltage: 364.8 V
Gear Ratio 1/7.94
Curb Weight 1521 kg
0-100 km/h ~ 10 sec
Drag Coefficient 0.28
Inverter Frequency 5 kHz
Assumed
PMSM Electric Motor Max power / torque: 100 kW / 178 Nm, 8 poles
Inverter Efficiency 90%
Gear Efficiency 97%
Wheel Radius 0.3 m

3. © 2015 Synopsys, Inc. 3
Simplified Electric Vehicle Powertrain
Modeled after Market Available Electric Vehicle
Published
PMSM Electric Motor Max power / torque: 80 kW / 280 Nm
Li-Ion Battery
Total energy: 24 kWh
Max power > 90 kW
Number of cells: 192 (2 parallel, 96 series)
Cell voltage: 3.8 V
Nominal system voltage: 364.8 V
Gear Ratio 1/7.94
Curb Weight 1521 kg
0-100 km/h ~ 10 sec
Drag Coefficient 0.28
Inverter Frequency 5 kHz
Assumed
PMSM Electric Motor Max power / torque: 100 kW / 178 Nm, 8 poles
Inverter Efficiency 90%
Gear Efficiency 97%
Wheel Radius 0.3 m
IPMSM model from
JMAG-RT Motor Model
Library

4. © 2015 Synopsys, Inc. 4
1
2
3
4• Level 1
– Behavioral Li-Ion battery
– Dynamic thermal dq inverter and PMSM
– Thermal network
• Level 2
– Average/non-switching inverter /w TLU losses
– LdLq or detailed FEA-based PMSM
• Level 3
– Ideal switch inverter /w TLU losses
• Level 4
– Improved datasheet-driven IGBT1
Abstraction Levels

5. © 2015 Synopsys, Inc. 5
1

6. © 2015 Synopsys, Inc. 6
1Simplified Vehicle Dynamics

7. © 2015 Synopsys, Inc. 7
1
ia,va
ib,vb
ic,vc
a
b
c
Sinusoidal currents and switching/PWM voltages are abstracted to only
retain phase and amplitude of signals in synchronous reference frame
iq
id
vq
vd
i
v

8. © 2015 Synopsys, Inc. 8
1
FEA-based look-up tables used for
flux saturation Ld(id) and Lq(iq), and
speed/current dependent iron loss

9. © 2015 Synopsys, Inc. 9
1Reactance Torque

10. © 2015 Synopsys, Inc. 10
1
NS
Reactance Torque

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1Reactance Torque
angle
torque
90o

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1Reluctance Torque
Br
Hc
m
The permanent magnets have low
permeability / high reluctance (~ air
gap). The rotor orients itself in the
position of least flux resistance.

13. © 2015 Synopsys, Inc. 13
1
Average Inverter Model
including Efficiency Map

14. © 2015 Synopsys, Inc. 14
Switching Losses
1
≈ 𝛼 ∙ 𝒗 𝒐𝒇𝒇 ∙ 𝒊 𝒐𝒏
on+off
𝑷 𝒔𝒘 = 𝑬 𝒔𝒘 ∙ 𝒇 𝒔
= 𝑬 𝒔𝒘 (𝒗 𝒐𝒇𝒇, 𝒊 𝒐𝒏)
rec+
𝒊 𝒐𝒏 (𝑨) 𝒗 𝒐𝒇𝒇 (𝑽)
𝑬 𝒔𝒘 (𝑱)

15. © 2015 Synopsys, Inc. 15
v
i
one 1D look-up table: 𝑃 𝑐(𝑖) = 𝑖. 𝑣(𝑖)
Conduction Losses
1

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1
Field Oriented Control
Vector Control

17. © 2015 Synopsys, Inc. 17
1
𝑖∗2
= 𝑖 𝑑
∗2
+ 𝑖 𝑞
∗2
𝜕𝑇
𝜕𝑖∗ = 0
𝑖 𝑑
∗
=
𝜑 𝑚 − 𝜑 𝑚
2 + 8 𝐿 𝑞 − 𝐿 𝑑
2
𝑖∗2
4 𝐿 𝑞 − 𝐿 𝑑
𝑖 𝑞
∗
= 𝑠𝑔𝑛(𝑖∗) 𝑖∗2
− 𝑖 𝑑
∗2
Maximum Torque Per Amp
𝑖 𝑑
∗
𝑖 𝑞
∗
𝑖∗
Field Oriented ControlField Oriented Control
MTPA 𝑖∗
𝑖 𝑑
∗
𝜃𝑖
𝑖 𝑞
∗
𝑖 𝑑
𝑖 𝑞

18. © 2015 Synopsys, Inc. 18
1Flux Weakening
𝑖 𝑑
∗
𝑖 𝑞
∗
𝑖 𝑑
𝑖 𝑞
Field Oriented Control

19. © 2015 Synopsys, Inc. 19
1Flux Weakening
𝑖 𝑑
∗
𝑖 𝑞
∗
𝑖 𝑑
𝑖 𝑞
Field Oriented Control
𝑉𝑞 = 𝑅𝑖 𝑞 + 𝐿 𝑞
𝑑𝑖 𝑞
𝑑𝑡
+ 𝜔 𝐿 𝑑 𝑖 𝑑 + 𝜑 𝑚
𝑉𝑑 = 𝑅𝑖 𝑑 + 𝐿 𝑑
𝑑𝑖 𝑑
𝑑𝑡
− 𝜔𝐿 𝑞 𝑖 𝑞
𝑇 =
3
4
𝑝 𝜑 𝑚 𝑖 𝑞 + 𝐿 𝑑 − 𝐿 𝑞 𝑖 𝑑 𝑖 𝑞
R neglected,
steady-state

20. © 2015 Synopsys, Inc. 20
1Flux Weakening
𝑖 𝑑
∗
𝑖 𝑞
∗
𝑖 𝑑
𝑖 𝑞
Field Oriented Control
𝑉𝑞 = 𝜔 𝐿 𝑑 𝑖 𝑑 + 𝜑 𝑚
𝑉𝑑 = −𝜔𝐿 𝑞 𝑖 𝑞
𝑇 =
3
4
𝑝 𝜑 𝑚 𝑖 𝑞 + 𝐿 𝑑 − 𝐿 𝑞 𝑖 𝑑 𝑖 𝑞
At high speed, back-EMF
exceeds DC link voltage

21. © 2015 Synopsys, Inc. 21
1Flux Weakening
𝑖 𝑑
∗
𝑖 𝑞
∗
𝑖 𝑑
𝑖 𝑞
Field Oriented Control
𝑉𝑞 = 𝜔 𝐿 𝑑 𝑖 𝑑 + 𝜑 𝑚
𝑉𝑑 = −𝜔𝐿 𝑞 𝑖 𝑞
𝑇 =
3
4
𝑝 𝜑 𝑚 𝑖 𝑞 + 𝐿 𝑑 − 𝐿 𝑞 𝑖 𝑑 𝑖 𝑞
Increase current angle (negative
component of id) to “weaken”
magnet flux and reduce back-EMF

22. © 2015 Synopsys, Inc. 22
𝑖 𝑑
∗
𝑖 𝑞
∗
𝑖 𝑑
𝑖 𝑞
Field Oriented Control
MTPA 𝑖
−
𝜑 𝑚
𝐿 𝑑
𝜑 𝑚
𝐿 𝑞 − 𝐿 𝑑
𝑖 𝑞
𝑖 𝑑
1Flux Weakening
𝑉𝑞 = 𝜔 𝐿 𝑑 𝑖 𝑑 + 𝜑 𝑚
𝑉𝑑 = −𝜔𝐿 𝑞 𝑖 𝑞
𝑇 =
3
4
𝑝 𝜑 𝑚 𝑖 𝑞 + 𝐿 𝑑 − 𝐿 𝑞 𝑖 𝑑 𝑖 𝑞
Increase current angle (negative
component of id) to “weaken”
magnet flux and reduce back-EMF
𝑣2
= 𝑣 𝑑
2
+ 𝑣 𝑞
2
Voltage Limit Ellipse
𝑣2
𝜔2
= 𝐿 𝑑 𝑖 𝑑 + 𝜑 𝑚
2
+ 𝐿 𝑞
2
𝑖 𝑞
2
𝜃𝑖

23. © 2015 Synopsys, Inc. 23
𝑖 𝑑
∗
𝑖 𝑞
∗
𝑖 𝑑
𝑖 𝑞
Field Oriented Control
MTPA
𝑖
−
𝜑 𝑚
𝐿 𝑑
𝜑 𝑚
𝐿 𝑞 − 𝐿 𝑑
Increasing Speed
𝑖 𝑞
𝑖 𝑑
1Flux Weakening
𝑉𝑞 = 𝜔 𝐿 𝑑 𝑖 𝑑 + 𝜑 𝑚
𝑉𝑑 = −𝜔𝐿 𝑞 𝑖 𝑞
𝑇 =
3
4
𝑝 𝜑 𝑚 𝑖 𝑞 + 𝐿 𝑑 − 𝐿 𝑞 𝑖 𝑑 𝑖 𝑞
Increase current angle (negative
component of id) to “weaken”
magnet flux and reduce back-EMF
𝜃𝑖
𝑣2
= 𝑣 𝑑
2
+ 𝑣 𝑞
2
Voltage Limit Ellipse
𝑣2
𝜔2
= 𝐿 𝑑 𝑖 𝑑 + 𝜑 𝑚
2
+ 𝐿 𝑞
2
𝑖 𝑞
2

24. © 2015 Synopsys, Inc. 24
1
Field Oriented Control
𝑉𝑞 = 𝜔 𝐿 𝑑 𝑖 𝑑 + 𝜑 𝑚
𝑉𝑑 = −𝜔𝐿 𝑞 𝑖 𝑞
𝑇 =
3
4
𝑝 𝜑 𝑚 𝑖 𝑞 + 𝐿 𝑑 − 𝐿 𝑞 𝑖 𝑑 𝑖 𝑞
Feedforward Compensation

25. © 2015 Synopsys, Inc. 25
1• Analyze system efficiency over long driving cycles
• Evaluate energy flow in critical regimes
(deceleration, braking)
• Handle power dissipation and cooling
• Design stable motor control (e.g. FOC)

26. © 2015 Synopsys, Inc. 26
1• Analyze system efficiency over long driving cycles
• Evaluate energy flow in critical regimes
(deceleration, braking)
• Handle power dissipation and cooling
• Design stable motor control (e.g. FOC)

27. © 2015 Synopsys, Inc. 27
1
2
Sinusoidal currents and voltages (no switching)

28. © 2015 Synopsys, Inc. 28
1
2
a
b
c
𝜃 𝑚
𝜃𝑖
i
Accounts for
1. Mutual coupling between phases
2. Flux saturation
3. Spatial harmonics

29. © 2015 Synopsys, Inc. 29
1
2
• Analyze system dynamics
• Evaluate energy flow in critical regimes
(deceleration, braking)
• Design stable motor control (e.g. FOC)
• Evaluate torque ripples
Motor
Torque
Regenerative
Braking
Sloped Terrain Startup

30. © 2015 Synopsys, Inc. 30
1
2
• Analyze system dynamics
• Evaluate energy flow in critical regimes
(deceleration, braking)
• Design stable motor control (e.g. FOC)
• Evaluate torque ripples
Torque ripples due to
spatial harmonics

31. © 2015 Synopsys, Inc. 31
1
2
3
• Design PWM control (e.g. compensate dead time distortion)
• Mitigate faults in critical regimes (e.g. in flux weakening mode)
Dead time distortion
(corrected and uncorrected)

32. © 2015 Synopsys, Inc. 32
1
2
3
4
• Optimize gate drive tradeoff losses vs. EMI noise
• Control current/voltage overshoot
• Prevent accidental turn-on
𝑖 = 𝐶𝑐𝑔 ∙
𝑑𝑉𝑐𝑒
𝑑𝑡
≫ 1
Vg < Vge(th)
Rg
Vgei > Vge(th)
c
e
𝑉 = 𝐿 𝑒 ∙
𝑑𝑖 𝑐
𝑑𝑡
≪ −1
Accidental turn-on
mechanisms

33. © 2015 Synopsys, Inc. 33
2016.03 IGBT Tool
• Improved matching of transient
characteristics
– Cge made non-linear
– Control of turn-off voltage oscillations
– Decoupling between turn-on and turn-off
• Easier characterization
– Optimizer at most steps, including
transient characteristics
– Turn-on and turn-off characteristics
combined in one view
– Improved DC anchor points
– Library of pre-characterized components
– Numerous bug fixes

34. © 2015 Synopsys, Inc. 34
IGBT Principle
Collector/Anode
Emitter/Cathode
P+ Emitter
Gate
P
N- Base
P+
N+
• Two junctions
– J1 space charge region develops
when Vce < 0
– J2 space charge region develops
when Vce > 0 and Vge < Vge(th)
– Wide and low doped N- base region
→ large blocking voltage
• BJT+MOSFET
– Insulated gate → voltage control
– Holes injected from P+ emitter →
conductivity modulation
– High forward conduction current
density: 𝑖 𝑐 = 𝑖 𝑚𝑜𝑠 + 𝑖 𝑝
• Slow removal of carriers in the
base → longer switching time
during turn-off and tail current
J1
J2
+
+

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IGBT Principle
Collector/Anode
Emitter/Cathode
P+ Emitter
Gate
P
N- Base
Rb
PNP
N-MOS
P+
N+
imos ip
(𝛽)
++
+
holes
electrons
• Two junctions
– J1 space charge region develops
when Vce < 0
– J2 space charge region develops
when Vce > 0 and Vge < Vge(th)
– Wide and low doped N- base region
→ large blocking voltage
• BJT+MOSFET
– Insulated gate → voltage control
– Holes injected from P+ emitter →
conductivity modulation
– High forward conduction current
density: 𝑖 𝑐 = 𝑖 𝑚𝑜𝑠 + 𝑖 𝑝
• Slow removal of carriers in the
base → longer switching time
during turn-off and tail current

36. © 2015 Synopsys, Inc. 36
IGBT Principle
Collector/Anode
Emitter/Cathode
P+ Emitter
Gate
P
N- Base
P+
N+
imos ip+
+
• Two junctions
– J1 space charge region develops
when Vce < 0
– J2 space charge region develops
when Vce > 0 and Vge < Vge(th)
– Wide and low doped N- base region
→ large blocking voltage
• BJT+MOSFET
– Insulated gate → voltage control
– Holes injected from P+ emitter →
conductivity modulation
– High forward conduction current
density: 𝑖 𝑐 = 𝑖 𝑚𝑜𝑠 + 𝑖 𝑝
• Slow removal of carriers in the
base → longer switching time
during turn-off and tail current

37. © 2015 Synopsys, Inc. 37
IGBT Principle
Collector/Anode
Emitter/Cathode
P+ Emitter
Gate
P
N- Base
P+
N+
+• Two junctions
– J1 space charge region develops
when Vce < 0
– J2 space charge region develops
when Vce > 0 and Vge < Vge(th)
– Wide and low doped N- base region
→ large blocking voltage
• BJT+MOSFET
– Insulated gate → voltage control
– Holes injected from P+ emitter →
conductivity modulation
– High forward conduction current
density: 𝑖 𝑐 = 𝑖 𝑚𝑜𝑠 + 𝑖 𝑝
• Slow removal of carriers in the
base → longer switching time
during turn-off and tail current

38. © 2015 Synopsys, Inc. 38

39. © 2015 Synopsys, Inc. 39
IKW75N65EL5
Static Characteristics

40. © 2015 Synopsys, Inc. 40
Quasi-Static Characteristics
IKW75N65EL5

41. © 2015 Synopsys, Inc. 41
IKW75N65EL5
Quasi-Static Characteristics

42. © 2015 Synopsys, Inc. 42
Ic
Vcc
Inductive Clamp Test Circuit
Vcc
Rg(off)
Vg(on)
Vg(off)
Lp
DUT
(IGBT)
-15V
Ic
DUT
(Diode)
Rg(on)
Vg(on)

43. © 2015 Synopsys, Inc. 43
11
1
1
2
2
2
2
3
3
3
3
4
4
4
4
5
5
5
5
𝐶𝑟𝑒𝑠 = 𝐶𝑔𝑐
𝐶𝑖𝑒𝑠 = 𝐶𝑔𝑐 + 𝐶𝑔𝑒
𝐶𝑜𝑒𝑠 = 𝐶𝑔𝑐 + 𝐶𝑐𝑒

44. © 2015 Synopsys, Inc. 44
𝐶𝑟𝑒𝑠 = 𝐶𝑔𝑐
𝐶𝑖𝑒𝑠 = 𝐶𝑔𝑐 + 𝐶𝑔𝑒
𝐶𝑜𝑒𝑠 = 𝐶𝑔𝑐 + 𝐶𝑐𝑒
Cies = dQg / dVgs
Miller plateau Vgs
~1.2nF
~1.2nF

45. © 2015 Synopsys, Inc. 45
IKW75N65EL5
Non Quasi-Static Characteristics

46. © 2015 Synopsys, Inc. 46
IKW75N65EL5
Non Quasi-Static Characteristics

47. © 2015 Synopsys, Inc. 47
IKW75N65EL5
Non Quasi-Static Characteristics

48. © 2015 Synopsys, Inc. 48
IKW75N65EL5
Thermal Characteristics
Cauer networkFoster network
Duty cycle zero
sufficient to match
the other curvesOnly physical if
connected to
temperature source

49. © 2015 Synopsys, Inc. 49
Future Work
• Merging of MOSFET and IGBT
tools
• Improve DC characteristics for
SiC MOSFET’s
• sw1_l4 and pwld with accurate
switching losses (TLU)
• Battery characterization tool
(with enhanced model)
NXP TrenchMOS BUK9640-100A