Optimal Rotor Shape Design of a Concentrated Flux IPM-Type Motor for Improving Efficiency and Operation Range

In this paper, an optimal design for a concentrated flux interior permanent magnet (CFIPM) motor is proposed to improve efficiency and obtain a wide operation range simultaneously. For enhancement in efficiency in the constant torque region, the saliency ratio is increased with respect to the initial model. Two points, 3000 rpm (based speed) in the constant torque region and 7000 rpm (maximum speed) in the constant power region, are chosen so as to compare the torque in our design with that of the initial model. A 2D-finite element method (FEM) was used to calculate the inductances of the d-axis and q-axis with a change in the CFIPM rotor shape. In the optimal design, the Kriging method based on Latin hypercube sampling (LHS) and a genetic algorithm (GA) were employed. The validity of the optimal design was verified by 2D-FEM and current vector control.