Study on High Voltage Reverse Bias (HTRB) Test Method of 6.5 kV High-Voltage IGBT Modules for Railway

In this article, a temperature stabilization method of high-temperature reverse bias (HTRB) and high-voltage high-temperature high-humidity reverse bias (HV-H3TRB) tests for 6.5 kV high-voltage power IGBT modules used in railway is proposed. The traditional climate chamber is not suitable for stabilizing the temperature of high-voltage IGBT modules, as there are multi-chips connected in parallel, which can create a high leakage current during the high-voltage blocking state at high junction temperature. The proposed junction temperature stabilization method can avoid thermal runaway caused by positive feedback between power loss and junction temperature in HTRB and HV-H3TRB tests, and the effectiveness is confirmed by experimental results. Furthermore, a precise junction temperature measurement method based on leakage current is proposed, which can be used to set initial junction temperature correctly for HTRB and HV-H3TRB tests.