Optimization and Mechanical Strength Analysis of Less-Rare-Earth Interior Permanent-Magnet Synchronous Machines Used for Electric Vehicles

This paper investigates the optimization and mechanical strength analysis of the less-rare-earth interior permanent-magnet synchronous machines (LRE-IPMSMs) used for electric vehicles, which are characterized by high power density, high efficiency and low cost. Firstly, the structure parameters of the investigated LRE-IPMSM including the PM thickness and flux barrier location angle are optimized. Secondly, the stress distribution of the investigated LRE-IPMSM is analyzed as the investigated LRE-IPMSM has a high maximum speed. Then, the effects of the bridge shape and location on the maximum stress and electromagnetic torque are studied. Finally, the optimal LRE-IPMSM is proposed by taking various factors into consideration.