Study on the Analysis and Reduction Method for AC Copper Loss in Electric Vehicle Traction Motor

The advancements in electrified drive systems have enabled the design of high-power density electric vehicle (EV) motors. However, the increased operating frequency necessary for achieving high-power density amplifies AC copper losses, primarily due to skin and proximity effects. This study focuses on reducing AC copper losses in an 8-pole, 48-slot Interior Permanent Magnet Synchronous Motor (IPMSM) using 2D finite element analysis (FEA). The analysis evaluates the contributions of skin and proximity effects to total copper losses and investigates the influence of slot leakage flux. Additionally, the impact of slot and conductor geometries on leakage flux, its variation over time, and the resulting AC copper losses were systematically analyzed. By balancing manufacturability and performance, optimal design parameters were derived to minimize AC copper losses. The results demonstrate that adjustments in slot width, slot depth, and conductor placement significantly affect leakage flux and copper losses. The proposed design strategies improve motor efficiency and thermal performance under high-speed operating conditions, contributing to the development of high-performance EV motors.