Optimal design of PM motors for quasi-sinusoidal air-gap flux density

This paper presents an optimal design method for the rotor structure of permanent magnet synchronous motor by using Finite Element Method (FEM) combined with Pulse Width Modulation (PWM). The PWM technique is applied to the shape of the surface of the solid iron rotor and the magnets are buried. Calculation is straightforward and show that the radial air-gap flux density harmonics are eliminated leading to almost sinusoidal air-gap flux density. The well known Field Orientated Control (FOC) strategy is applied to control the machine. It is reinforced by a proper field weakening strategy for high speed applications. Simulation results on the entire speed range are satisfactory. In addition, analysis of the harmonics content of air-gap flux density, back-EMF and torque waveform is given and verifies the above claim.

[1]  Noureddine Takorabet,et al.  DESIGN TECHNIQUE FOR REDUCING THE COGGING TORQUE IN LARGE SURFACE-MOUNTED MAGNET MOTORS , 2006 .

[2]  Zhang Qianfan,et al.  Hybrid Switched Reluctance Motor Applied in Electric Vehicles , 2007, 2007 IEEE Vehicle Power and Propulsion Conference.

[3]  Nicola Bianchi,et al.  Design techniques for reducing the cogging torque in surface-mounted PM motors , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).

[4]  N. Takorabet,et al.  On the Use of Pulse Width Modulation Method for the Elimination of Flux Density Harmonics in the Air-Gap of Surface PM Motors , 2009, IEEE Transactions on Magnetics.

[5]  Thomas M. Jahns,et al.  Pulsating torque minimization techniques for permanent magnet AC motor drives-a review , 1996, IEEE Trans. Ind. Electron..

[6]  G. Slemon,et al.  Reduction of cogging torque in permanent magnet motors , 1988 .

[7]  Gan Zhang,et al.  A Novel Hybrid Excitation Flux-Switching Motor for Hybrid Vehicles , 2009, IEEE Transactions on Magnetics.