Diagnosis method of stator inter-turn short-circuit fault in double-fed asynchronous motor based on d-q theory
This paper proposes a fault diagnosis method based on the characteristic frequency compo-nent of rotor current for early detection of inter-turn short-circuit faults in the stator windings of double-fed asynchronous motors. Firstly,the electromagnetic characteristics of the motor post-fault analysis indicate the generation of a characteristic frequency component in the rotor current. Then,a three-phase current is derived from a specific phase-shifted single-phase rotor current,followed by d-q transformation to demonstrate that the amplitude of the transformed DC component reflects the mag-nitude of the characteristic harmonics. This DC component serves as a fault characteristic quantity for diagnosing inter-turn short-circuit faults in double-fed asynchronous motor stator windings. The fault diagnosis for turn-to-turn faults is conducted using finite element theory. Finally,a simulation model of the motor pre and post-fault is established utilizing the finite element method to investigate the varia-tions in fault characteristic quantity under diverse operational conditions. The results indicate a positive correlation between the fault characteristic quantity extracted using the d-q theory and the number of short-circuited turns in the stator winding. Effective diagnosis of inter-turn short-circuit faults is achieved under variable rotational speeds and unbalanced voltages through the setting of reasonable fault thresholds,providing a new methodology for diagnosing turn-to-turn short-circuit faults in motor windings.
double-fed asynchronous motorsstator winding inter-turn short-circuitfault diagnosisd-q transformation theory
万方数据
维普
