Mixed Stator-Rotor fault characterization for Doubly Fed Induction Machines

This paper introduces a diagnostic technique for the detection of mixed Stator-Rotor electrical faults in Doubly Fed Induction Machine (DFIM) for wind power systems. Operating in aggressive environments, the detection of anomalies at an incipient stage is crucial to decide about the operating continuity of the machines. In this paper the behavior of DFIM is investigated under the assumption that the stator and rotor windings are simultaneously unbalanced owing to faults or incipient windings damage. The aim of the presented work is to investigate the spectral signature frequencies issued from stator and rotor currents under mixed stator-rotor asymmetry. The derived chains of interhamonics are firstly validated by numerical simulations, and then by experimental tests with a 5.5 kW wound rotor induction motor.