Eddy current analysis of a PWM controlled induction machine

Abstract

Purpose

The purpose of this paper is to propose a transmission line model for induction machines, which serves to compute the common mode input impedance in the frequency range 10 Hz-1 MHz.

Design/methodology/approach

Special diligence is attributed to the modelling of eddy currents inside the core lamination. In order to determine the transmission line parameters accurately, two modelling approaches are compared. The first is a two-dimensional simulation approach where iron core lamination effects are included by means of an equivalent material approximation. The second approach consists in fully three-dimensional analysis taking into account explicitly the eddy currents induced in the laminations.

Findings

It is shown that homogenised equivalent material models may lead to large errors in the calculation of machine inductances, especially at high frequencies. However, the common mode input impedance, which is the final parameter of interest, seems to be less affected by the lamination modelling.

Originality/value

The paper compares different analytical and numerical approaches in the frequency range 10 Hz-1 MHz and tries to give benchmarks for errors which occur due to a number of commonly used model simplifications.

Citation

Van Jorks, H., Gjonaj, E. and Weiland, T. (2013), "Eddy current analysis of a PWM controlled induction machine", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 32 No. 5, pp. 1609-1619. https://doi.org/10.1108/COMPEL-04-2013-0128