Using a Surge Tester to Detect Rotor Eccentricity Faults in Induction Motors

This paper discusses a new method to detect rotor eccentricity faults in induction motors using a so-called surge test that is applied to the stator windings. Rotor eccentricity faults cause an asymmetrical air gap in induction motors, which makes the surge waveform shape depend on rotor position. The change of surge waveform per revolution can be used to indicate any abnormal air gap problem clearly. The feasibility of this detection scheme is verified by experiments. The surge test is a nonintrusive, cost-efficient, and reliable offline method that is particularly useful for routine and predictive maintenance.