IPT Electronics: High Power Density InverterINVERTER R&D IPT Electronics : High Power Density...

INVERTER R&D

IPT Electronics : High Power Density Inverter

�

300V)

�

coolant, 450ARMS at 72C coolant

� 22kg => 3000W/kg

bidirectional DC-DC converter)

� Advanced power control circuits

� High accuracy torque control

� Designed for automotive reliability

DC-DC Converter Section

Traction Inverter Section

65kW at 250V (80kW at

500ARMS at 57C

(includes 3/2kW

INVERTER R&D

VD C VA C MM M T

ID C IA C N M N T

Customer Specification

Ansoft/Speed

DyRoBeS

Motor Requirements

Motor Thermal Design

Inverter Requirements

Motor Electromagnetic Design

Cost Evaluation

Transmission Requirements

Preliminary Design

Preliminary Design

Performance Evaluation

System Simulation Framework – E-Drives

Inverter

Controller

M otor Transmission DC Supply Load

Matlab/Simulink

Matlab

MotorCad/Ansoft

Motor Mechanical Design

Transmission Assumptions

INVERTER R&D

Advanced Technology Developments

Power Semiconductor Packaging Design & Manufacturing

INVERTER R&D

• Thermal Stress on wire bonds

•

ECOSTAR POWER MODULE FACILITY

Interconnection

Therm

al&

Induct

ance

PathsReliability

Spatial

Require

men

ts

Inductive effects in Power Module

Silicon Efficiency

INVERTER R&D

Thermal and Mechanical Properties of Each Layers

( 3 ) (W/ (J/ (ppm/

8979 389 381

3100 150 880 227

/ 8470 50

8930 170 431 327

/ 11100 35

2703 796

2760 237 70

2330 oC oC

oC oC

702

Material Density

kg mThermal condutivity

m K) Specific heat

kg K) Young’s modile

(GPa) CTE

K)

Copper 112.9 16.4

AlSiC 6.8

60Sn 40 Pb solder 364.5 29.8 21.1

DBC AIN 2.5

95Pb 5Sn solder 133.7 20.4 25.1

Thermal grease 0.735 0.011 16.4

Aluminum 858.8 23.6

Silicon 153 @ 25 119 @ 77

98.9 @ 127 76.2 @ 227

112.9 2.54

INVERTER R&D

Thermal Resistance Predicted Using Numerical Tools

CAD model

Temperature predicted from CFD simulation

� In developing Ballard Custom Power Module with integrated

fluid dynamics (CFD) was used to simulate fluid flow along fins and heat transfer within solids.

� The predicted maximum junction-to-coolant thermal resistance is 0.09 oC/W per switch, and the average number is about 0.08 oC/W per switch.

pinfin baseplate, computational

INVERTER R&D

Junction Temperature of IGBT and Diode

Temperature predicted from CFD simulation for CPM with pinfin baseplate

Inl

l

� Application condition similar to IPT “Full Torque Stall”.

� Power loss is 350W for IGBT and 105W for Diode per switch.

� Coolant inlet temperature is 85 oC, flow rate is 2 gpm.

i l lSi i i lSi

T (oC) 139 118

T (oC) 127 112

IGBT and Diode Temperature for CPMs with Flat and Pinfin Baseplates

118.2

85.0

88.3

91.6

95.0

98.3

101.6

104.9

108.2

111.6

114.9

et

Out et

CPM w th f at A C baseplate CPM w th pinf n A C baseplate

jIGBT

jDiode

INVERTER R&D

Comparison

� Thermal resistance reduced by 40% for integrated pin-fin power module.

lat in ion

l i

o o 40%

j i97 oC oC 40% *

i105 oC oC 47% *

i ion inl oC i i

Standard fbaseplate

Integrated pin-fbaseplate

Percentage reduct

Average thermaresistance per sw tch

0.12 C/W 0.07 C/W

Average IGBT unct on temperature

81

Max mum measured IGBT temperature

84

* Note: Percentage reduct on refers to temperature difference between junct and coolant that has et temperature of 60 n th s test.

INVERTER R&D

Problem Approach to Inductance Challenge

1.00 Simulation & Modeling of Structure

2.00 Inductance formulae for current paths

3.00 Physical Systems Test

INVERTER R&D

Inductance Analysis

OBJECTIVES

•

�

• Optimize layout for minimum inductance Reduce Parasitics

• Lower switching losses • Minimize effects of body diode recovery • Reduce bond wire stress • Minimize EMI

Alternative Embedded Busbar Structures

INVERTER R&D

�Inductance Analysis of the D.C. Link

ANSOFT Simulation Model

i ls

Ta Tb Tc

Sa Sb Sc

Units = nH

Measured Results

Term nashorted phase

4.5 7.2 9.2 6.0 4.1 6.0 9.2 7.2 4.5

INVERTER R&D

0

1

nH

Physical Testing Formulae Based 15 mil wire

0

1

0

Ind

uct

ance

in n

H

nH

Path Inductance - The Bond Wires

Delta Inductance - 15 mil & 20 mil Wires

0.2

0.4

0.6

0.8

1.2

Wire #'s - (1-2), (2-3), (3-4)

20mil 15 mil

Path Inductance of Bond Wires

0.2

0.4

0.6

0.8

10 20 30

Wire Diameter in mil

INVERTER R&D

Achieved Benefits

� Increased package performance: � Significant reduction in

parasitic inductance � Significant reduction in

thermal resistance � Increased power density

� Increase packaging integration

� Reduced system packaging space

� Reduced system cost � Improved reliability

INVERTER R&D

Transient Thermals

Cu baseplate With Al203 DBC

DBC.

a 10% improvement in thermal resistance Due to the Aln

Comparison

° C/W

1.00 E-05

1.00 E-04

1.00 E-03

1.00 E-02

1.00 E-01

1.00 E +00

1.00 E-05

1.00 E-04

1.00 E-03

1.00 E-02

1.00 E-01

1.00 E+00

1.00 E+01

Cu Junction to Base Cu Substrate to Base - Al203

AlSic : Junction to Base AlSic : Substrate to Base - AlN

100mS - Pulse - 800A Power Module

compared to

AlSic and Aln

AlSic & Aln offers

DBC substrate

INVERTER R&D

Materials Reliability

30

50

70

90

13

0

15

0

lii

lii ing

i lSi ln

i l

Comparison

improvement

1.00 E-03

1.00 E-04

1.00 E+05

1.00 E+06

1.00 E+07

1.00 E +08

110

Temperature Delta in Tj

Wire Bond Capabi ty with coat ng

Wire Bond Capabi ty with NO protect ve coat

Solder fat gue for A c & A

Solder fat gue for Cu & A 203

• Cu with Al203

• AlSic with Aln

• Wire Bond Coating

INVERTER R&D

POWER SILICON

• IGBT Heat Diffusion

.

• Stress in bond wire.

This view is below bond wire

- IGBT Devices evaluated -Eupec, Semikron, ABB, Toshiba, Hitachi, Fuji

INVERTER R&D

TOSHIBA

IGBT Technical Trend for Cross Section (600V – 1700V)

Conventional DesignConventional Design Current DesignCurrent Design Future DesignFuture Design

Collector

P+

N Buffer

N- (Epi)

N+

P- Base P+

Emitter

PT-Trench Thin NPT-Trench Ultra Thin PT-Trench Emitter

P+

Gate

N­

N­

P+P+

N+ N+

P- Base

N Buffer

P+

Gate

P- Base

Emitter

Collector

Gate

Collector

• Ultra Thin Wafer

• Low Injection Efficiency

Improvement for Trade off of

Eoff-VCE(sat)

Improvement forTrade off of

Eoff-VCE(sat)

Ultra-Thin-PT-TrenchPT-PlanerThin-NPT-Trench

INVERTER R&D

TOSHIBA

600V IGBT Eoff-VCE(sat) Trade-off

Eof

f (m

J/A

)

25

PT-PlanerThin NPT-TrenchUltra Thin PT-Trench

PT-Planer (Conventional)

Thin NPT-Trench (Latest)

Ultra Thin PT-Trench (Future) VS VS

Eoff - VCE(sat) of 600V Type

0.00

0.02

0.04

0.06

0.08

0.10

0.12

1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8

VCE(sat) (V)

Future(Target) Compact MIP

@V C C =300V, IC =Rated-IC , VGE=+-15V

125

INVERTER R&D

Switching Waveforms

-25

-20

-15

-10

-5

0

5

10

15

20

25

0 100 -700

-600

-500

-400

-300

-200

-100

0

0

Clamped inductive load switching at 25C.

diode

current voltage

200 300 400 500

Time (ns)

Id (

A)

100 200 300 400

Time (ns)

Vd

(V

)

Red trace SiC, blue trace 1200V hyperfast Si pin

500

INVERTER R&D

Reverse Recovery Summary

25C

3

37%

Qrr (nC) 446 28 6%

i PJ) 139 9

PJ) 198 149 75%

125C

12.5 3 24%

37 19 51%

Recovered charge 231 28 12%

�PJ) 69 9 13%

�PJ) 173 149 86%

Si PiN SiC SiC vs Si

Peak reverse current Ipr (A) 17.5 17%

Reverse recovery time Trr (ns) 51 19

Recovered charge

Diode loss Eoff D ode ( 6%

IGBT loss Eon IGBT (

Si PiN SiC SiC vs Si

Peak reverse current Ipr (A)

Reverse recovery time Trr (ns)

Qrr (nC)

Diode loss Eoff Diode

IGBT loss Eon IGBT

INVERTER R&D

Hybrid Power Inverter Development

Power Inverter Hardware & Analysis for a Hybrid Vehicle Platform

INVERTER R&D

PM Synchronous Motor Model

INVERTER R&D

l

0

l

PM Synchronous Motor – 15 kW Operation

15 kW Peak Operating Points

0.0

50.0

100.0

150.0

200.0

250.0

300.0

0.0 1000.0 2000.0 3000.0 4000.0 5000.0 6000.0

Motor Speed, RPM

To

rqu

e (N

m)

Cu

rren

t (A

pk)

Vo

ltag

e (V

rms)

0.000

0.200

0.400

0.600

0.800

1.000

1.200

Torque L-N Vo tage, Pk Phase Current, Pk Power Factor

15 kW Continuous Operating Points

0.0

50.0

100.0

150.0

200.0

250.0

1000 2000 3000 4000 5000 6000

Motor Speed, RPM

To

rqu

e (N

m)

Cu

rren

t (A

pk)

Vo

ltag

e (V

rms)

0.000

0.200

0.400

0.600

0.800

1.000

Torque L-N Vo tage, Vpk Phase Current, Pk Power Pactor

INVERTER R&D

0

50

100

150

1 2 3 4

i i i i i i ion

Maximum Coolant Temperature – 15 kW Drive

15 kW Inverter - CPM IGBTs / Switch

-150

-100

-50

Number of IGBT Die Per Switch

Max

imu

m A

llow

able

Co

ola

nt

Tem

per

atu

re, C

8 kHz Sw tch ng 4 kHz Sw tch ng 2 kHz Sw tch ng Phase-Phase Rotat

12 April 2003

INVERTER R&D

0

50

100

150

1 2 3 4

i i i i i i ion

il 2003

Maximum Coolant Temperature – 25 kW Drive

25 kW Inverter - CPM IGBTs / Switch

-150

-100

-50

Number of IGBT Die Per Switch

Max

imu

m A

llow

able

Co

ola

nt

Tem

per

atu

re, C

8 kHz Swtch ng 4 kHz Swtch ng 2 kHz Swtch ng Phase-Phase Rotat

12 Apr

INVERTER R&D

Voltage Overshoot Reduction

Integrated DC-Bus Snubbers

INVERTER R&D

Further Work

•

• Silicon integration of gate drive and sensing circuits.

•EMI containment

Thermistor

Silicon Sensor

Vs

Faster Temperature Sensing of Silicon Junction.

- Turn-on speed and diode recovery. - DC Bus Capacitance integrated with

Busbar in module.