Accurate Electro-Thermal Computational Model Design and Validation for Inverters of Automotive Electric Drivetrain Applications

Abstract

This paper proposes the fast and accurate electro-thermal model of the existing Simrod three-phase inverter for an electric vehicle (EV) application. The research focuses on analytical and dynamic electro-thermal models of inverters that can be applied for multi-applications. The optimal design approach of passive filters is presented for the DC and AC sides of the inverter. The analytical model has been established, including a mathematical representation of the inverter and induction motor (IM). The high-fidelity electro-thermal simulation model of an inverter with integrated power loss and thermal model is established. The state-space thermal model (for the IRFS4115PbF device) has been created and incorporated into the MATLAB simulation. The simulation model is then validated with the PLECS software-based thermal model to confirm the accuracy. Indirect field-oriented control (IFOC) is designed for squirrel-cage IM at a maximum power rating of 45 kW and implemented on MATLAB/Simulink. The comparative analysis between the real and simulated results is performed to validate the simulation model at a specific speed, torque, and current. Furthermore, the electro-thermal simulation model has been validated with experimental data using efficiency and temperature comparison. The developed simulation model is beneficial for designing, optimizing, and developing advanced technology-based inverters to achieve higher efficiency at a particular operating range of temperature and power quality. The new European driving cycle (NEDC) speed profile simulation results are demonstrated.