Wing technique as a comprehensive method for stator and rotor inter-turn fault diagnosis in wound rotor induction motors

Condition monitoring plays a pivotal role in safeguarding three-phase induction motors (IMs) commonly utilized in industrial and commercial settings. This study focuses on wound rotor induction motors (WRIMs), specifically addressing the adverse impact of the stator and rotor winding inter-turn short circuits. Unlike prevalent literature concentrating on squirrel cage induction motors (SCIMs) and emphasizing stator inter-turn and broken rotor bar faults, this paper introduces a comprehensive technique applicable to detecting inter-turn faults (ITFs) in WRIMs. The proposed method ensures stable motor operation and averts catastrophic failures. Experimental validation is conducted on a three-phase, 7.5 hp, 415 V WRIM, affirming the technique's effectiveness under conditions of unbalanced source voltages and asymmetries in stator and rotor windings. The approach employs motor currents-based experimental emulation, utilizing loci of instantaneous symmetrical components of three-phase stator currents, pound (i(s1)- i(s2)) and rotor currents pound (i(r1)- i(r2)) for stator and rotor ITFs detection, respectively. Termed the 'Wing Technique' (WT), this method derives its name from the distinctive 'Wing Shape' formed by these loci.