Magnet Shape Optimization of Surface-Mounted Permanent-Magnet Motors to Reduce Harmonic Iron Losses

Surface-mounted permanent-magnet (PM) synchronous motors are widely applied to electric vehicles, where iron losses reduction is a crucial target. This paper proposes a new method of PM shape optimization to reduce the harmonics of magnetic field and, hence, iron losses. The proposed method is based on the analytical calculation of magnetic field distribution with a non-uniform PM shape, which can save much computation time compared with the parameter sweep method. The validity of the method is verified by 2-D finite-element analysis.