Description of magnetic hysteresis effects in electrical drives by a circuit model approach

Abstract

In this paper a magnetic circuit model approach, which is able to describe hysteresis in electric machines, is presented. The method describes the ferromagnetic structure of an electric machine by a magnetic model circuit. Each part of the machine is described by permeances which can be linear or non linear, with hysteresis or not, in accordance with the material which this part is made of. The magnetic permeability needed to compute each permeance is described by Preisach's method. The presented model, based on Preisach's hysteresis scalar theory, allows to calculate not only the global hysteresis losses, but also the losses in each part of the machine as well as the distortion of the induced electromotive force (emf) and of the voltages. In order to verify this method, two cases have been examined: a) a transformer case; b) a switched reluctance drive. The first one has been experimentally tested the second one has been used to compare an alternative approach based on a FEM commercial package.