Test setup for accelerated test of high power IGBT modules with online monitoring of V<inf>ce</inf> and V<inf>f</inf> voltage during converter operation

Abstract

Several accelerated test methods exist in order to study the failures mechanisms of the high power IGBT modules like temperature cycling test or power cycles based on DC current pulses. The main drawback is that the test conditions do not represent the real performance and stress conditions of the device in real application. The hypothesis is that ageing of power modules closer to real environment including cooling system, full dc-link voltage and continuous PWM operation could lead to more accurate study of failure mechanism. A new type of test setup is proposed, which can create different real load conditions like in the field. Furthermore, collector-emitter voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce</sub> ) has been used as indicator of the wear-out of the high power IGBT module. The innovative monitoring system implemented in the test setup is capable of measure the V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce</sub> and forward voltage of the antiparallel diode (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> ) during converter operation, which is also demonstrated.