Wind Turbine Blade Imbalance Monitoring Using PMSG Electrical Signals

This paper presents a new fault diagnosis method of wind turbine (WT) blade mass imbalance and blade pitch imbalance using the electrical output signals of permanent magnet synchronous generator (PMSG) in a wind turbine. It extracts the tach signals from the electrical signals for ordertracking and noise suppression. The power variations of the electrical signals generated by the PMSG at different faults are compared and it is found that the power variations are of irregular type between different mass imbalance. Whereas, the amplitude difference of power increases with the increase of pitch imbalance in the case of pitch imbalance. Meanwhile, this paper utilizes the method based on angular domain resampling order tracking to resample the current signal in the angular domain, and conducts spectral analysis on the resampled data to find out the characteristic frequency during the imbalance, and the results are consistent with the theoretical results. It is also found that the amplitude of the blade rotation frequency increases with the increase of imbalance, which further verifies the effectiveness of this Electric Signature based Order Tracking Analysis (ES-OTA) method for WT monitoring and diagnosis.