VP7-03 High-Efficiency-Region Broadening Design and Analysis of A Variable-Leakage-Flux Permanent Magnet Motor from the Perspective of Losses Replacement
Creators: Min Jiang
Xiaoyong Zhu
Zixuan Xiang
Publisher: name: IEEE
Year: 2025

With the increasing complexity of traffic conditions around the world, the driving cycle of EVs has attracted more and more attention in the field of drive motor research. The high-efficiency driving of the drive motor under multiple operation conditions cannot be satisfied by the improvement of single-operation-point efficiency. Thus, in [1], the efficiencies under different flux leakage states of a flux-leakage controllable permanent magnet are improved. Yet, the ignorance of the driving cycle brings poor adaptability to the working conditions of EVs. Meanwhile, the efficiencies of representative points, picked out according to the distribution of actual operation points, are improved in [2], emphasizing the driving cycle and ignoring the characteristics of the motor itself, affecting the fit between the motor and the drive cycle. In this paper, according to the distribution of actual operating points of EVs, the high-efficiency region of the drive motor is broadened directionally, improving the operation quality of the drive motor. Fig. 1(a) shows the topology and efficiency map of the research variable leakage flux permanent magnet (VLF-PM) motor, and the distribution of high-energy operating points of the typical New European Driving Cycle (NEDC). To orientally broaden the high-efficiency region of the VLF-PM motor, the key operation points are selected as the key operating points and marked in Fig. 1(a). The derivative of core loss and copper loss on output torque under the 6 key operation points are calculated and presented in Fig. 1(b) and (c). Then, the rated performances of the initial motor and improved motor are compared and shown in Fig. 2. It can be seen that based on the directional losses replacement, the efficiencies of the 6 key operation points are all improved. As a result, with similar speed-torque and speed-power characteristics, the high-efficiency region is directionally broadened, improving the efficiency of the operation points in NEDC. More detailed theoretical analysis and experimental results will be given in full paper.References: [1] X. Zhou, X. Zhu, W. Wu, Z. X and et al, “Multi-objective optimization design of variable-saliency-ratio pm motor considering driving cycles,” IEEE Trans. Ind. Electron., vol. 68, no. 8, pp. 6516-6526(2021). [2] X. Sun, Z. Shi, Y. Cai, , and et al, “Driving-Cycle-Oriented Design Optimization of a Permanent Magnet Hub Motor Drive System for a Four-Wheel-Drive Electric Vehicle”, IEEE Trans. Transport. Electrific., vol. 6, no. 3, pp. 1115-1125(2019).
With the increasing complexity of traffic conditions around the world, the driving cycle of EVs has attracted more and more attention in the field of drive motor research. The high-efficiency driving of the drive motor under multiple operation conditions cannot be satisfied by the improvement of single-operation-point efficiency. Thus, in [1], the efficiencies under different flux leakage states of a flux-leakage controllable permanent magnet are improved. Yet, the ignorance of the driving cycle brings poor adaptability to the working conditions of EVs. Meanwhile, the efficiencies of representative points, picked out according to the distribution of actual operation points, are improved in [2], emphasizing the driving cycle and ignoring the characteristics of the motor itself, affecting the fit between the motor and the drive cycle. In this paper, according to the distribution of actual operating points of EVs, the high-efficiency region of the drive motor is broadened directionally, improving the operation quality of the drive motor. Fig. 1(a) shows the topology and efficiency map of the research variable leakage flux permanent magnet (VLF-PM) motor, and the distribution of high-energy operating points of the typical New European Driving Cycle (NEDC). To orientally broaden the high-efficiency region of the VLF-PM motor, the key operation points are selected as the key operating points and marked in Fig. 1(a). The derivative of core loss and copper loss on output torque under the 6 key operation points are calculated and presented in Fig. 1(b) and (c). Then, the rated performances of the initial motor and improved motor are compared and shown in Fig. 2. It can be seen that based on the directional losses replacement, the efficiencies of the 6 key operation points are all improved. As a result, with similar speed-torque and speed-power characteristics, the high-efficiency region is directionally broadened, improving the efficiency of the operation points in NEDC. More detailed theoretical analysis and experimental results will be given in full paper.References: [1] X. Zhou, X. Zhu, W. Wu, Z. X and et al, “Multi-objective optimization design of variable-saliency-ratio pm motor considering driving cycles,” IEEE Trans. Ind. Electron., vol. 68, no. 8, pp. 6516-6526(2021). [2] X. Sun, Z. Shi, Y. Cai, , and et al, “Driving-Cycle-Oriented Design Optimization of a Permanent Magnet Hub Motor Drive System for a Four-Wheel-Drive Electric Vehicle”, IEEE Trans. Transport. Electrific., vol. 6, no. 3, pp. 1115-1125(2019).