Fault Indicators for the Diagnosis of Rotor Faults in FOC Induction Motor Drives

In this paper, different diagnostic techniques are proposed for the diagnosis of rotor faults in field oriented controlled (FOC) induction motor drives. In particular, the applicability of the estimated rotor flux, the current error signals and the outputs of the current controllers of a FOC drive are analyzed. Some block diagrams are presented which can be used to establish useful relationships between the effects of a rotor fault in different motor and controller variables. Based on these results, several fault indicators are defined, stressing the advantages and limitations of each one regarding their robustness against the operating conditions of the motor, easiness of implementation in a DSP board and filtering needs.