Comparative Analysis of Traction Inverter Controllers for the Mission-Profile Oriented Reliability and Performance Evaluation in Electric Vehicles

In this paper the individual component lifetime of an insulated-gate bipolar transistor (IGBT) traction inverter driving an Interior Permanent Magnet Synchronous Motor (IPMSM) is assessed. The performance is compared for two different control strategies during an 1800s WLTC driving cycle. The first strategy is Indirect Field Oriented Control (IFOC) with Maximum-Torque-Per-Ampere (MTPA) and Maximum-Torque-Per-Voltage (MTPV) with sinusoidal pulse width modulation (SPWM). The second control strategy is a Direct Torque Model Predictive Control (DTMPC), specifically the Finite Control Set Optimal Switching Vector (FCS-OSV) MPC. A high-fidelity electro-thermal model of the inverter is used to calculate losses and junction temperatures of IGBTs and diodes. The proprietary physics-of-failure based reliability assessment tool (RELAT) is used to evaluate individual component's reliability percentile based on the junction temperature variation during a WLTC driving cycle. The MPC-controlled traction inverter shows 25.6% less losses, 1.2–1.77% lower junction temperatures, and 21% faster reliability degradation compared to the inverter with the IFOC.