Lifetime investigation of high power IGBT modules

This article concerns lifetime investigation of high power IGBT modules. Other research investigating wind turbine failures of modern wind turbines observed that the power converter counts for 15% of all failures. A test bench capable of testing the IGBT power modules in an accelerated application specific working point was constructed. The working point was given with regards to voltage, current, power and phase. An analysis of failure mechanisms in modern IGBT modules was conducted. From this it was concluded that V
_CE
of the IGBTs can be used as an indication of wear out of an IGBT module. Through circuit analysis and other studies it was concluded that a change of around 30 mV was to be expected. A innovative measuring system capable of measuring V
_CE
of the IGBTs and V
_D
of the diodes with high accuracy was implemented. Three test periods was conducted, and each period lasted 7-14 days. Every 5 minutes all V
_CE
and V
_D
voltage drop were measured and saved. From the measurements it was concluded that the wear out of IGBT modules can be traced through V
_CE
and V
_D
.