Research on IGBT Junction Temperature Failure in Wind Turbine Converters under High Temperature and Humidity Conditions

To investigate the impact of junction temperature conditions on failure modes and mechanisms of Insulated Gate Bipolar Transistor (IGBT) devices in high-temperature and humid environments, this study adopts an engineering perspective. Through on-site IGBT disassembly, mapping, and temperature rise data collection, a three-dimensional transient fluid-thermal coupling finite element model of wind turbine IGBTs was established to simulate and analyze failure mechanisms. Simulation and experimental results indicate that IGBT chipset failures are influenced by junction temperature fluctuations. The four corner regions where chips and the compression layer contact are more prone to cracking under cyclic thermal loads, with severe cases exhibiting delamination. After packaging the IGBT hybrid module, interlayer voids lead to significant increases in temperature and thermal stress, reducing module reliability, with larger voids exacerbating these effects.