Research On Modeling And Diagnosis Methods Of DFIG Stator Winding Inter-turn Short Circuit Fault

In the face of the increasingly serious energy security and environmental degradation,the development of wind power has become an important decision of China's sustainable development strategy.With the rapid development of wind power technology and equipment level,wind power has become the most mature technology,the most large-scale development conditions and commercial development prospects of new energy.Doubly-fed induction generator(DFIG)has the ability to adjust the active power and reactive power,the maximum wind speed tracking constant frequency operation capacity,and because the capacity of the excitation converter is less than the rated capacity of the wind power system,greatly reducing the system cost.These factors make it the mainstream of the wind power market models.Based on the knowledge of multi-loop theory,this paper builds the normal and faulty simulation model of DFIG in MATLAB and solves the loop equations by using the S-function programming.Then,under the condition of converter control,the current waveform of normal and stator inter-turn short-circuited is analyzed by spectrum,and the corresponding fault diagnosis conclusion is obtained.At the same time,a fault diagnosis method based on SVM and D-S evidence theory for information fusion is proposed for DFIG stator inter-turn short circuit fault.And the fault feature quantity in the park transformation model and the residual voltage afler switch-off model is used as the signal source for fault fusion processing.The results of the final fusion show that this method can improve the d iagnosis rate of the fault and prove its effectiveness compared with the single fault diagnosis.So as to provide theoretical basis for DFIG early fault diagnosis.