Nonlinear multi-harmonic finite-element simulation of a capacitor motor

¹ Katholieke Universiteit Leuven, Campus Kortrijk, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium
² Institut für Theorie Elektromagnetischer Felder, Technische Universität Darmstadt, Schloßgartenstraße 8, 64289 Darmstadt, Germany

Corresponding author: herbert.degersem@kuleuven-kortrijk.be

Received: 18 January 2007
Accepted: 12 June 2007
Published online: 12 July 2007

Abstract

Steady-state operation modes of three-phase induction machines can be efficiently simulated by 2D nonlinear time-harmonic finite-element models, although only induced currents with respect to the fundamental air-gap field are correctly taken into account. This technique does not generalise to single-phase induction machines. An approach based on multiple rotor models and a spectral decomposition of the air-gap field enables to consider higher harmonic air-gap field contributions. In a capacitor-motor model, the first, third and fifth forward and backward rotating components give raise to different frequencies in the rotor which result in different eddy-current effects. The torque dip due to the third harmonic is accurately simulated.