Induction motors diagnosis using deceleration test, a possible improvement

Noninvasive diagnosis of incipient or actual faults of grid supplied induction machine is a well known technology. Motor current signature analysis (MCSA) can be used for rotor and stator defects. These include stator current harmonics at frequencies (1 ± 2s) f and also determining the negative sequence component of current space vector. Deceleration tests which possibly can remove several drawbacks of MCSA have been proposed for rotor and stator fault diagnosis. This paper attempts to compare the MCSA-based diagnostic procedures with the results obtained using the deceleration tests. Experimental results show that although the deceleration test does not provide clear information on rotor defects, it provides a diagnostic index directly related to the percentage of shorted turns. This diagnostic index can be used to validate the MCSA-based diagnostic procedure.