Pseudo-salient model of induction machine with broken rotor bars

Abstract

In this paper, a dynamic model of a squirrel cage induction motor with broken rotor bars, is presented. The model is based on the assumption that the asymmetry due to broken bars is reflected through different resistances and inductances in a two-phase rotor model. Their joint effect is best expressed through rotor time constant. Mathematical equations, based on this premise, have been developed in rotor reference frame, thus obtaining a very simple yet effective model of the machine. Additionally, a method for measurement of both time constants of a faulty rotor at standstill is explained. Simulation results, based on this model, have been experimentally verified for healthy and faulty machine, showing very good agreement at different operational points. Finally, a study of the impact of various relationships between the parameters in both rotor axes on the behavior of the simulation model, is performed.