Evolution of high order fault harmonics during a bar breakage with compensation

Under certain circumstances the widespread Motor Current Signature Analysis focused on low frequency components used to detect rotor bar breakages in induction motors cannot provide an adequate indication of this defect. This work studies the behavior of high order components during the last stage of a fatigue test designed to reproduce a natural bar breakage, in which a compensation of the indicators generally used to diagnose the fault is observed. Some of these higher frequency harmonics remain unaffected, accurately depicting the entire bar breakage both in transient and stationary operation, which may be of application for the detection of a double fault in the rotor cage.