Optimization of rotor shape for constant torque characteristic of IPM motor

This paper deals with optimal design of notch and flux barrier in order to improve the characteristics of constant torque while minimizing the cogging torque. The position and width of the notch was calculated using the Fast Fourier Transform. The optimized model using the notch and barrier demonstrated a 60% decrease in the cogging torque, a 75.3% decrease in the torque ripple, and a 3% increase in the operating torque when compared with the basic model. Thus, the operating characteristics were significantly improved.