A Multi-mode aging decoupling monitoring method for IGBT modules based on TSEPs separation strategy

The health condition of insulate gate bipolar transistor (IGBT) modules directly determines whether the entire power electronics system can operate stably over the long term. Currently, IGBT module health monitoring methods mainly focus on single failure modes. However, in engineering applications, IGBT modules often undergo multiple types of aging due to the combined effects of electrical, thermal, and mechanical stresses. Moreover, the high-speed switching of IGBT modules generates significant self-heating, accurate junction temperature prediction is also critically important. To address the above issues, this paper proposes a multi-mode aging decoupling monitoring method for IGBT modules based on temperature sensitive electrical parameters (TSEPs) separation strategy. By analyzing the effects of junction temperature variation, gate oxide degradation, and bond wires lift-off on pre-threshold voltage change rate dV_th-pre/dt, threshold voltage V_th, and auxiliary emitter voltage V_eE, the specificity of these parameters to junction temperature and different aging modes are obtained, achieving multi-mode aging decoupling. The experimental results show that the proposed method can effectively identify IGBT modules gate oxide degradation or bond wires lift-off while predicting the junction temperature. It is also capable of decoupling and quantifying each aging mode degrees, and exhibits a certain level of immunity to load current variations.