High-Efficiency-Region Broadening Design and Analysis of a Variable-Leakage-Flux Permanent Magnet Motor From the Perspective of Losses Replacement

In this article, to improve the efficiency of the high-energy operation points of electric vehicles (EVs), a high-efficiency region broadening design method by replacing losses is proposed. By analyzing the interrelationship between copper loss, core loss, and output torque, the replacement directions for various losses are identified. Based on this analysis, a strategy for directed loss replacement is proposed, which involves optimizing the design of the permanent magnets (PMs) and magnetic barriers to modify the distribution of the PM flux density. This approach effectively improves the loss distribution and enhances the motor’s operational efficiency. Finally, a comparison of key performances between the initial and improved motors demonstrates that this method can significantly expand the high-efficiency region.