Analysis of Broken Rotor bar Fault Diagnosis for Induction Motor

Induction motors are widely used motors in industrial applications. These are reliable and robust, however may develop a multitude of faults related to machine components like bearings, stator or rotor, etc. Consequently, a number of motor fault identification methods have been developed in the past years for their early diagnosis. This paper gives a comparative analysis for detection and diagnosis of broken rotor bar faults occurring in three phase induction motors fed through variable speed drive. Firstly, it gives a brief overview of two widely used methods known as Motor Current Signature Analysis (MCSA) and Park's Vector Analysis (PVA). Secondly, it provides the details of experimentation carried out to find the presence of broken rotor bar fault and judge their severity. Further, a comparative analysis of both methods is provided in finding the presence and judging the severity of broken rotor bars for motors operating under different loading conditions. PVA is used here successfully for experimentally determining fault severity. Motor parameters such as current, voltage and slip are used as diagnosis means for finding the presence of broken rotor bars and estimating their number. Since fault indicators in motor parameters are highly dependent on operating conditions, the data is acquired for different motor loading. The results obtained are compared and verified using both the methods.