Overtemperature Protection of Power Electronic Modules with Reduced Driveline Oscillations in Electric Vehicles

This paper presents the design of a temperature controller to prevent overtemperature failures in three-phase inverters for electric drive applications. Here, a combination of online estimators is utilized to estimate the critical semiconductor losses and junction temperatures. Then, the temperature controller actively manipulates the maximum allowable phase current to ensure safe operation within the power module junction temperature limits. Oscillations in the maximum allowable phase current output of the temperature controller (e.g., due to the dynamics of the device power losses and temperatures at low speed) are mitigated using a phase current limit ripple controller. This ripple controller utilizes a stiffness gain to alter the amount of ripple suppression. Detailed simulation and experimental results for Field-Effect Transistor (FET) and Insulated Gate Bipolar Transistor (IGBT) based inverters show the effectiveness of the proposed controller across various operating conditions.