Squirrel-cage Induction Machine Broken Bars Fault Detection Using Adjustable Speed Drives

The need for detection of rotor faults at an earlier stage, so that maintenance can be planned ahead, has pushed the development of monitoring methods with increasing sensitivity and noise immunity. Addressing diagnostic techniques based on current signatures analysis (MCSA), the anomalous components introduced by a specific fault in the current spectrum are investigated and diagnostic procedure is able to correlate the amplitude of these components to the fault extent. In this paper, the impact of feedback control on asymmetric rotor cage induction machine behavior is presented. The diagnostic variables usually used for open-loop operation are no longer effective under closed-loop operation. Simulation results show that signals already present at the drive have suitable features that can lead to an effective diagnostic procedure