Teeth shape optimization of surface and interior permanent-magnet motors with concentrated windings to reduce magnet eddy current losses

The teeth shapes of permanent-magnet motors with concentrated windings are optimized in order to reduce the eddy-current losses of magnets. First, the main factors that cause the magnet eddy-current losses in surface and interior permanent-magnet motors are discussed by analyzing the variation in flux distributions. Next, automatic optimizations are carried out for each motor by using the adaptive finite element method. The validity of the calculation is confirmed by the experiment of prototype motors. It is clarified that the optimized teeth shapes of the surface and interior permanent-magnet motors are significantly different from each other because of the difference in the main factors that cause the magnet eddy-current losses.