Optimal Shape Design of Rotor Slot in Induction Motor Considering Starting and Rated Currents

The configuration of rotor slot has a great impact on induction motor characteristics. However the shape of a rotor slot can change the input current and the increase of input current causes the dielectric breakdown of an induction motor. So considering input currents of working conditions is needed in design process. An optimization procedure for rotor slot design of an induction motor to maximize rated torque is proposed using finite element based level set method and the material boundaries of rotor slot are represented by a level set function. Voltage driven analysis based on time harmonic field with external electric circuit is performed, then torque and current at each slip are calculated. To prevent the failure of the induction motor, current constraints are set at rated and starting condition. The proposed method is applied to the reference design problem and validated to improve the design