Comparison of two modeling methods for induction machine study:: application to diagnosis

This paper presents two modeling methods applied to induction machine study in order to construct a tool for diagnosis purpose. The first method is based on permeance networks using finite element analysis to calculate magnetic equivalent circuit parameters. The second method consists of the elaboration of an electric equivalent circuit obtained from minimal geometrical knowledge on stator and rotor parts of the machine on study. These two methods are presented and their results are compared with respect to the normal and rotor broken bar operation. For this study, a simple structure induction machine with three stator coils and six rotor bars has been investigated. The presented results concern stator currents and electromagnetic torque for the rated speed and the magnitude of the stator current harmonic components have been compared.