Programmable Design of Magnet Shape for Permanent-Magnet Synchronous Motors With Sinusoidal Back EMF Waveforms

• Published in: IEEE transactions on magnetics Vol. 44; no. 9; pp. 2163 - 2167
• Main Authors: Yong Li, Yong Li, Jingwei Xing, Jingwei Xing, Tianbao Wang, Tianbao Wang, Yongping Lu, Yongping Lu
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.09.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: ANSOFT; Brushless DC motors; Cross-disciplinary physics: materials science; rheology; Cylinders; DC motors; EMF; Exact sciences and technology; FEM; Harmonic distortion; magnet shape; Magnetic analysis; Magnetic flux; Magnetism; Materials science; Mathematical models; Motors; optimal design; Optimization; Other topics in materials science; Permanent magnet motors; Physics; PMSM; Rotors; Saturation magnetization; Servomotors; Shape; Synchronous motors; Waveforms; Design; Finite element method; optimal design; PMSM; magnet shape; Wave forms; Synchronous motors; Permanent magnets; ANSOFT; Magnetic properties; FEM
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2008.2000750

The characteristics of a permanent-magnet synchronous motor (PMSM) are influenced greatly by the back-electromotive force waveforms in the motor, which are directly related to the magnet shape. We assume that the outer surface of a magnet in a PMSM can be modeled as one part of a cylinder. Using an ANSOFT model, we optimized the radius of the magnet with respect to number of poles, rotor size, and magnet thickness when the total harmonic distortion is below 1%. We then set up a lookup table using the optimization results so that the desired outer radius of a magnet of any new PMSM motor could be derived, subject to the parameter limits. We applied this method to some PMSM prototypes, and confirmed that the calculation results are substantially accurate.