Non-invasive Condition Monitoring (Pre-fault) of IGBT Power Modules in 3-Level NPC for EV Applications

Power semiconductor modules often comprise multiple chips to attain appropriate current and voltage ratings for electric vehicles and industrial applications. The solder fatigue on the base plate of the IGBT module represents a significant failure mode in power converters. These failures are particularly pertinent in EV applications that involve regular driving, regenerative braking, and acceleration. A novel approach is introduced in this study to assess the health condition of the IGBT module during base-plate solder fatigue, focusing on temperature differences across the casing. This article proposes an accurate electro-thermal model that effectively determines the junction temperature of the IGBT module. The designed electro-thermal model estimates the junction temperature precisely by considering the effects of device-level and module-level thermal parameters. A coupled three-dimensional (3D) thermal network model is created for IGBT modules and associated heatsinks in Ansys and PLECS environments. Using the electro-thermal model, the experimental results validate the efficacy of the proposed method in determining the deterioration level of the semiconductor power module. The proposed condition monitoring also integrates IoT to monitor the real-time temperature of IGBT modules and heat sinks under different operating and test conditions.