Some observations on induction motor frequency characterizations under variable supply conditions

Induction motors are most popularly used in modern day industrial drives. Under operating stresses and ageing, both stator and rotor of an induction motor undergoes degradation. It is necessary to properly assess the condition of motors on operation for reliable performance. Popularly employed technique for motor condition monitoring is the motor current signature analysis (MCSA) that deals with frequency response of the stator current. The stator current frequency response, along with motor internal conditions, is affected by supply conditions as well. The aim of this paper is to study effects of stator supply voltage variations on motor frequency response. Experimental and simulation study results are reported in this paper.