1DOE/Scandia PV Inverter Reliability Workshop

IGBT ReliabilityIssues and Needs

John Donlon

Powerex, Inc.173 Pavilion Lane

Youngwood, PA 15697724-925-4377

jdonlon@pwrx.com

2DOE/Scandia PV Inverter Reliability Workshop

The Most Powerful Alliance in the

Power-Electronics Field

General Electric

Mitsubishi Electric

Powerex

3

• Corporate offices in Youngwood, PA

• 280 employees

• 120,000 square feet of facilities

• Design & manufacture

– Rectifiers and Thyristors

– Custom Modules

– Integrated POW-R-PAKs

• Sales & Marketing, Engineering, & Logistics for Mitsubishi

in the Americas

– IGBTs, IPMs, & MOSFET Modules

4DOE/Scandia PV Inverter Reliability Workshop

Topics

Failure Modes

Mitigation

Industry perspective

Future Advances

Predictive Data

Switching scheme robustness

5

Failure Modes

• Voltage

• Current

• SwSOA

• Temperature

• Mechanical (cycling/fatigue)

6DOE/Scandia PV Inverter Reliability Workshop

Voltage

IGBTs have very limited avalanche capability so the rated voltage must never be exceeded…

Not even for a nano-second!!

7DOE/Scandia PV Inverter Reliability Workshop

Voltage

• Over Voltage

• Cosmic Ray Effect

8DOE/Scandia PV Inverter Reliability Workshop

Current

• Tj Max

9DOE/Scandia PV Inverter Reliability Workshop

SwSOA

• Voltage

• Current

• Desaturation – linear operation

10DOE/Scandia PV Inverter Reliability Workshop

Temperature

• Tj Max

11DOE/Scandia PV Inverter Reliability Workshop

Cycling/Fatigue

• Power Cycling ΔTj

• Thermal Cycling ΔTc

12DOE/Scandia PV Inverter Reliability Workshop

Mitigation - Voltage

• Voltage Margin

• Low Inductance Bus

• Snubbers

• Consider Cosmic Ray Effect

13DOE/Scandia PV Inverter Reliability Workshop

Mitigation - Current

• Tj max Margin

14DOE/Scandia PV Inverter Reliability Workshop

Mitigation - SwSOA

• Voltage/Current Limits

• Gate Drive Design

15DOE/Scandia PV Inverter Reliability Workshop

Mitigation - Temperature

• Design Margin

• Know Your Customer/Application

16DOE/Scandia PV Inverter Reliability Workshop

Mitigation – Cycling/Fatigue

• Understand and Consider Up Front

• Limit ΔT

17DOE/Scandia PV Inverter Reliability Workshop

Industry Perspective

• IGBT Modules are Reliable

• IGBT is an Innocent Victim

• 30-50 FIT < 1 FIT

18DOE/Scandia PV Inverter Reliability Workshop

Future Advances

• Lower Loss Chips

• Innovative Packaging

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Predictive Data

• ?

• Proprietary

20DOE/Scandia PV Inverter Reliability Workshop

Switching Scheme Robustness

• ?

• Margin

• Limit Aggressiveness

• Know Your Application and Customer

• Field Test

21DOE/Scandia PV Inverter Reliability Workshop

Q & ACOMPARE

DELAYtTRIP

GATEDRIVE

AND

E

C

G

E

H-SeriesIGBTModule

VTRIP

V+

RG

+

Shut-Down

D1

Input

np+

n-

p+

n+

n-