Diagnosis of rotor faults in direct and indirect FOC induction motor drives

This paper is devoted to the diagnosis of rotor faults in direct and indirect rotor flux oriented controlled drives. Different diagnostic techniques are proposed and analyzed with this aim, putting in evidence the advantages and limitations of each one. It is demonstrated that depending on the structure of the control system, some diagnostic techniques may be applicable or not for the diagnosis of this type of fault. The estimated rotor flux and the reference value of the magnetizing current component are the variables which demonstrate higher potential to be used for diagnostic purposes. At the end, the possibility of diagnosing the fault not only when the drive is operating in steady-state but also in transient conditions is investigated.