Blade Imbalance Fault Diagnosis of DFIG based on Current Park's Transformation

Aiming at the impeller imbalance fault of the Doubly fed Induction Generator (DFIG), a fault characteristic extraction method based on stator current is proposed. Firstly, based on the model of DFIG and its drive chain, the expression of the DFIG impeller imbalance stator current is derived. Secondly, the three-phase current of the stator is processed by Park's Transformation. Then through spectrum analyzing the squared signal of the stator current vector, the fault can be diagnosed by observing the amplitude variation of the feature frequency in the squared signal. Finally, a DFIG simulation model of is established. The fault characteristics of impeller imbalance fault at different wind speeds are analyzed by the proposed method. The results indicate that the proposed impeller imbalance fault diagnosis method in this paper can effectively extract the fault.