Closed Loop Control Impact on the Diagnosis of Induction Motors Faults

In this paper, the impact of control on faulted induction machine behavior is presented. The diagnostic indexes usually used for open-loop operation are no longer effective. Simulation and experimental results show that the spectrum of the field current component in a field-oriented controlled machine has suitable features that can lead to an effective diagnostic procedure. Specifically, in the case of stator and rotor faults the spectrum components at frequencies 2sf and -2sf, respectively, are quite independent of control parameters and dependent on the fault extent.