Closed-loop bandwidth impact on MVSA for rotor broken bar diagnosis in IRFOC double squirrel cage induction motor drives

This paper investigates the detectability of rotor broken bars in indirect rotor flux oriented control (IRFOC) for variable speed double cage induction motor drives, using vibration signature analysis techniques. The Impact of the closed loop control system cannot be neglected when the detection of rotor asymmetries in the machine is based on the signature analysis of electrical or mechanical variables. Therefore, the investigation of rotor fault components for different bandwidths of closed-loop regulators is necessary to evaluate its relevance in the above listed variables. This paper investigates the impact of the control system on relevance of the fault components computed from axial and radial vibration signals. Experimental results show the validity of this impact, and more specifically, the bandwidth PI regulators. Due to its relevance, axial vibration analysis shows a more robust fault signature, under the control impact, in separating healthy from rotor bar breakage in double squirrel cage induction motors.