Optimal design and analysis of negative-saliency permanent magnet synchronous motor

• Published in: Dianji yu Kongzhi Xuebao = Electric Machines and Control Vol. 29; no. 6; p. 71
• Main Authors: Deng, Xianming, Tian, Yunfan, Chen, Chen, Zhang, Yu, Dai, Jingui
• Format: Journal Article
• Language: Chinese; English
• Published: Harbin Harbin University of Science and Technology 01.01.2025
• Subjects: Back electromotive force; Electromotive forces; Flux density; Harmonic distortion; Magnetic flux; Optimization; Parametric analysis; Permanent magnets; Quadratures; Rotors; Salience
• ISSN: 1007-449X
• DOI: 10.15938/j.emc.2025.06.008

Aiming at the demagnetization problem of permanent magnets in interior permanent magnet synchronous motors, a new structure of negative-saliency pole permanent magnet synchronous motor was proposed. This design solves the problem of excessive magnetic flux density by increasing the angle of the permanent magnets. Meanwhile, arc-shaped magnetic barriers were set on the permanent magnet side and the quadrature axis side of the rotor to reduce the leakage flux between the two poles of the rotor and improve the electromagnetic performance of the motor. Through parametric analysis, the influence of the relevant parameters of the arc-shaped magnetic barriers on the electromagnetic performance of the motor was obtained, making the effect of structural optimization more obvious. Through simulation comparison, it is found that after the structure was optimized, the magnetic flux density between the permanent magnet angles of the motor is 1.2 T, which is less than 1.6 T before optimization; the fundamental no-load back electromotive force is higher than that of the motor before optimization, and all harmonics except the 7th harmonic are less than those of the motor before optimization; the torque ripple is significantly smaller than that of the motor before optimization, and it shows better negative-saliency pole characteristics. Finally, a 1.1 kW prototype was built in the laboratory for experiments. The measured direct and quadrature axis inductances are 94.16 mH and 80.94 mH respectively, and the harmonic distortion rate of the no-load back electromotive force is 10.64%, verifying its feasibility and superiority.