Torque capability enhancement of commercial interior permanent magnet motors using t-shaped notching and merged barrier rotor topology

• This paper proposes an enhanced rotor topology for V-shaped commercial IPMSM, incorporating barrier merging and T-shaped notching techniques to enhance torque performance. • This work is first to report the combined application of barrier merging and T-shaped notching techniques in permanent magnet machines. • The optimization of machine design parameters is performed to achieve high torque performance. • The proposed motor indicated a significant improvement of torque and torque ripple. • The proposed rotor topology addresses limitations and significantly enhances performance of commercial EV motors. Interior permanent magnet synchronous motors (IPMSMs) are extensively used in electric vehicles (EVs) due to their robust rotor structure, wide speed range, and high efficiency. However, conventional IPMSM designs often suffer from torque ripple and limited torque density. This paper proposes an enhanced rotor topology for V-shaped commercial IPMSM, incorporating barrier merging and T-shaped notching techniques to enhance torque performance. The Tesla Model 3 commercial motor is adopted as the benchmark. A multi-objective genetic algorithm with sensitivity-based constraints is employed to optimizes key design parameters, and the electromagnetic performance is evaluated using 2D finite element analysis under no-load and on-load conditions. The optimized motor achieves a 3.86 % increase in back-EMF, a 6.2 % reduction in total harmonic distortion, and a 6.58 % decrease in cogging torque under no-load conditions. Under on-load conditions, the average torque is significantly improved by 7.4 %, and torque ripple is reduced by 24 % relative to its original value, indicating substantial improvements in torque capability. Additionally, the proposed motor achieves an efficiency of 92.93 %. A detailed analysis explains the underlying mechanisms contributing to these improvements, highlighting the potential of the proposed rotor topology to address existing limitations and significantly enhance performance of commercial EV motors.