Loss Calculation of Induction Motors Considering Harmonic Electromagnetic Fields in Stator and Rotor

Abstract

A method of loss calculation for induction motors is proposed. The combined 3D-2D time stepping finite element analysis is carried out to obtain the copper loss and the time-variation of the magnetic field in the motor. The iron loss is calculated approximately considering the time-variation of the magnetic field direction and the minor hysteresis loops caused by the time-harmonic fields using practical computer resources. The proposed method is applied to 4 types of induction motors, which are the solid rotor induction motors with/without slot and the cage induction motors with/without skew. The measured and the calculated total losses and the iron losses agree well in all cases. The differences of the loss distributions of each motor are also compared and investigated.