Some observation dealing with the failures of IGBT transistors in high power converters

The explosion strength of high power IGBT modules is one of the important parameters that may decide on converter equipment reliability in extreme circumstances. The explosion strength of a device is represented by the peak value of the collector current (so called “peak case nonrupture current”) that cannot be exceeded. Some main IGBT failure mechanisms under service conditions are discussed. Test methods and experimental results on device case explosion strength are presented. Experiences concerning starting, tests and service of high IGBT converters are given. Preliminary load tests with rapidly changing current values are useful for newly fabricated IGBT converters.