Optimum design of induction motors for electric vehicles

This paper presents the design procedure of a three-phase squirrel-cage ind uction motor for electric vehicles. The procedure takes into account the re quirements imposed by its use in vehicle traction. Also, the design conside rs the influence of the inverter by current and voltage harmonics. Because most of the requirements are antagonistic, the design procedure uses an obj ective function to select the optimal design. The objective function is a w eighted summation of the motor losses and the motor volume. The objective f unction is then augmented with the design constraints. The modified Hooke-J eeves search technique is adapted to solve this constrained nonlinear optim ization 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 imp rove the performance of the motor.