The use of the stator instantaneous complex apparent impedance signature analysis for discriminating stator winding faults and supply voltage unbalance in three-phase induction motors

This paper deals with a new on-line diagnostic scheme based on the use of the stator instantaneous complex apparent impedance signature analysis for stator winding inter-turn short-circuit faults diagnosis and their discrimination from the supply-voltage unbalance effects in operating three-phase squirrel cage induction motors. Both simulation and experimental results are presented to demonstrate the effectiveness and the capability of the new proposed approach that offers the possibility to distinguish between the two abnormality conditions by comparing, in each case, the signature analyses of the instantaneous real and imaginary parts of the considered quantity.