FE analysis of multiphase doubly salient PF permanent magnet motors

This paper presents the results of two-dimensional (2-D) finite-element analysis (FEA) carried out on 8/6 and 6/4 doubly salient permanent magnet (DSPM) motors to arrive at the magnet leakage factor and the flux density ratios of various parts of the motors so as to aid the designers of this newer motor. The two permanent magnets being kept embedded in the stator halves along with the typical doubly salient structure of the DSPM motor causes more leakage of the magnet flux. After extensive FEAs of the two configurations of the motors, it is observed that a magnet leakage factor of 1.32 is giving the correct results for use in conventional designs of this motor. Based on the optimum designs of the two motors, the flux densities in the airgap, rotor yoke, rotor pole, and stator yoke can be 1, 0.5, 0.9, and 0.5 times the flux density considered for the stator pole, which will normally be just above the knee-point value of the B-H characteristics of the core material used.