Detection of inter-turn short-circuit and broken rotor bars in induction motors using the Partial Relative Indexes: Application on the MCSA

Nowadays, the induction motors became the key element in all industrial plants. Early detection of abnormalities during motor operation would reduce the repair cost and the motor outage time. It was observed that most methods which are presented in literature for diagnosing motor faults are belonged to signal approach. Their philosophy supposes that each fault is characterized by specific spectral signatures on the spectra of acquired signals. However, practical cases show that occurrence of any kind of faults is often accompanied by complicated physical phenomena which extend its influences to other spectral components different from its signatures; this makes too difficult to locate the machine faults and poses then a big question about the concept of: Fault Signatures. In this context and in order to ameliorate the fault detection task, the present paper proposes the use of Partial Relative Indexes (PRI) as new fault indicators. Many experimental tests which are carried out on 3kW three-phase induction motors with broken bars and inter turn short-circuit corroborate our theoretical ideas and confirm the effectiveness of the proposed technique to detect such faults under different operation loads.