Fault Diagnosis of Doubly Fed Wind Power Generation System Based on Inter-Harmonic

By analyzing fault characteristics of stator current in doubly-fed wind power generation system when an electrical fault has occurred, a fault diagnosis method is proposed based on inter-harmonics feature frequency. The method can obtain inter-harmonics feature frequency in different working condition by detecting stator current and analyzing the three-phase current transformed by Hilbert-Huang Transform (HHT). In a fault condition, the fault type and location can be judged by inter-harmonics feature frequency which is produced by different phase. And a doubly-fed wind power generation system is simulated based on MATLAB/Simulink to verify the feasibility of the proposed method. The simulation result shows that in abnormal working conditions, the fault type and location can be determined based on the inter-harmonic feature frequency and HHT method can find feature frequency more accurately and quickly compared with Fast Fourier Transform (FFT), Empirical Mode Decomposition (EMD) and Fast Fourier Transform.