Diagnosis of Coexisting Broken Rotor Bars and Mixed Eccentricity in Induction Motors by Instantaneous Power Analysis

This paper analyses the effects of multiple faults in induction motors (IM), particularly mixed eccentricity and broken rotor bar occurring simultaneously are treated. This analysis is carried out by simulation, using a simplified sinusoidal model of the IM, and valeted experimentally by means a prototype of an IM with a high resistance rotor cage. By both simulation and experiment, the instantaneous active and reactive powers are obtained and their behaviors are compared. The results of this comparation shows that, for a certain range of fault frequencies, diagnosis is difficult, requiring a more detailed analysis or the use of complementary strategies in this situation.