The Rotor Fault Diagnosis Method of the Induction Motor Based on the D-S Evidential Theory

A method based on the D-S (Dempster-Shafer) evidential theory is presented and applied to diagnose the broken rotor bars of induction motors. Wavelet packets decomposition of the three-phase stator current is performed based on the frequency partition characteristics of the wavelet packets transformation; The faults characteristic vector (evidence) of the broken rotor bars is established by the RMS (Root Mean Square value) value of the wavelet nodes coefficient; Minkowaki distance measurement is used to construct basic reliability distribution function and to obtain its value which is is evidence as a result of the rotor faults. With the fused processing according to the D-S evidential fusion algorithm, the broken rotor bar faults of the motor is accurately identified. The experimental results demonstrated that reliable diagnosis of the broken rotor bars can be achieved by the proposed method.