Optimum Design of Induction Motors for Electric Vehicles

This paper presents the design procedure of a three-phase squirrel-cage induction motor for electric vehicles. The procedure takes into account the requirements imposed by its use in vehicle traction. Also, the design considers the influence of the inverter by current and voltage harmonics. Because most of the requirements are antagonistic, the design procedure uses an objective function to select the optimal design. The objective function is a weighted summation of the motor losses and the motor volume. The objective function is then augmented with the design constraints. The modified Hooke-Jeeves search technique is adapted to solve this constrained nonlinear optimization problem. The influence of the "copper weight/iron weight" ratio on the motor design is studied and the optimum ratio is chosen in order to improve the performance of the motor.