Thermal Parameter Monitoring of IGBT Module Using Junction Temperature Cooling Curves

In this paper, we propose a method to monitor the thermal parameters of insulated gate bipolar transistor (IGBT) module using the junction temperature cooling curves. Relationship between the time constants of junction temperature cooling curves and thermal parameters of the Cauer model is established for condition monitoring. Advantages of the proposed approach include no need to measure the power loss and to heat the module to thermal equilibrium. Simulation and experimental tests are performed to verify the accuracy and effectiveness of the proposed method. Results show that the proposed method can not only monitor the thermal parameter of a single layer, but also enable the concurrent monitoring of thermal parameters in multiple layers.