Compact modelling and analysis of power-sharing unbalances in IGBT-modules used in traction applications

IGBT modules are critical components for the reliability of power converters used in traction applications. A thorough analysis of all stressful operating conditions is a complex task, which requires versatile simulation capability. In this paper a comprehensive electro-thermal model of an IGBT-module is developed. Then, circuit simulation is used to investigate the power sharing between parallel chips during transient operation. Unbalances are observed, their causes identified and their influence on device degradation pointed out and discussed.