Improved Electro-Thermal Model Incorporating Device Aging Effect Towards Accurate Temperature Tracking in Electric Motor Drives

Accurate electro-thermal models are imperative for device junction temperature determination. Existing research focuses on electro-thermal model development based on the device
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characteristics in a healthy condition; however, it is important to observe the change in device characteristics in a degraded state as well to accommodate the change in temperature sensitive parameters such as collector-emitter voltage, resistance, and energy dissipation. Therefore, this paper develops an advanced electro-thermal model incorporating device aging effects. Initially, the device loss model is developed considering temperature sensitive electrical parameters. Subsequently, towards accurate junction temperature estimation, a novel thermal network model considering the thermal expansion due to device aging is derived. The proposed methodology is validated using a 100 kW inverter.