Simulation of an induction motor including eddy-current effects in core laminations

The purpose of this paper is to investigate the common mode ground current induced in an induction machine controlled by Pulse Width Modulation(PWM)at high frequencies. Using the transmission line approach the parameters are extracted from both two-dimensional (2D) and three-dimensional (3D) field simulations. 2D finite element (FE) analysis is an efficient tool for simulating the entire motor cross section. However, eddy currents in the lamination cannot be modeled explicitly and have to be approximated by a semi-analytical formulation. The paper investigates the accuracy of this model for a wide frequency range (100 Hz…100 kHz). The results show the necessity of fully 3D simulations taking into account the detailed distribution of eddy currents in the laminations. A specialized 3D simulation tool for induction motors with laminated cores is being developed and will be presented in the full paper.