A winding function theory based global method for the simulation of faulty induction machines

Abstract

This paper deals with a global method enabling the simulation of the squirrel cage induction machines under rotor and stator faults. This method is based on the coupled magnetic circuit theory. The system of differential equations describing the induction machine in presence of different rotor and stator faults is given. The machine inductances are calculated by means of the magnetic energy stored in the airgap. This task is performed by the use of the winding function method and a previously developed airgap permeance analytical model. Because of the inductances calculation is highly time consuming, a numerical representation method of the inductances is also proposed avoiding the calculation of the inductances during the differential equations system integration. The proposed model allows a precise study of several machine faults signature in various machine main quantities. Finally, some simulation results illustrate the proposed global method in the case of some common defaults such as stator inter-turn short circuits, broken rotor bars, broken end rings or airgap eccentricity.