Asymmetric T‐Shaped Notching Rotor Design for Torque Ripple and Cogging Torque Reduction in Interior Permanent Magnet Motors

Interior permanent magnet synchronous motors (IPMSMs) are regarded as the most promising candidate for electric vehicle (EV) propulsion systems due to their superior power density, efficiency, and robust rotor structure. However, mitigating torque ripple and cogging torque remains a critical challenge for ensuring the smooth operation of such machines. This paper introduces a novel asymmetric T‐shaped notching rotor topology designed to suppress these torque pulsations in a V‐shaped IPMSM used in the Tesla Model 3 platform. A multiobjective design framework utilizing sensitivity‐based constraints is implemented to optimize the notch geometry. Finite element analysis evaluates the electromagnetic performance under both no‐load and loaded conditions. Compared to the baseline design, the optimized asymmetric T‐shaped notching rotor yields a significant reduction of cogging torque by 52.3% and torque ripple by 10.5% while maintaining comparable average torque. The torque ripple mitigation is demonstrated across a broad range of currents and operating speeds. Analysis of the air‐gap harmonics and magnetic field distribution clarifies the underlying cause of these enhancements. Furthermore, the design exhibits lower core and magnet eddy current losses, resulting in improved efficiency across the operating range. The findings demonstrate that the asymmetric T‐shaped notching technique effectively suppresses torque pulsations in commercial EV traction machines without compromising torque magnitude.