Selection and Analysis of Rotor Structure for Expansion of IPMSM Operating Range

IPMSM is a high-torque, energy-saving motor used in automobiles and other vehicles. However, the increased torque at low RPM results in large losses at high RPM and high vibration, resulting in a narrower operating range. In this paper, we analyze and compare the characteristics of a 10-pole, 12-slot IPMSM in order to enhance reluctance torque for higher efficiency. The shapes of the base model and several rotor structures were compared. The spoke type resulted in the best vibration characteristics, while the flat plate type had the highest reluctance torque. Focusing on the spoke type with good vibration characteristics, the analysis was performed with a flux barrier to increase the reluctance torque, but the results were not what was sought, and the salient pole ratio was almost the same value.