DOUBLY-FED WIND TURBINE BLADE IMBALANCE DETECTION METHOD BASED ON STATOR CURRENT DATA

摘要

A doubly-fed wind turbine blade imbalance detection method based on stator current data is provided, comprising: if blade imbalance occurs, collecting multiple sets of information about a stator phase currentand a rotational speedin a constant-speed operation stage, performing a Hilbert transform to obtain an amplitude envelope signal, performing FFT on the envelope signal, and obtaining the amplitude when a turbine is at 1x rotational frequency; performing fitting by a least-squares method with respect to the relationship between the amplitude at the 1x rotational frequency and the stator phase current when the blades are balanced; during operation of the doubly-fed wind turbine, collecting a stator phase currentand a rotational speedin the constant-speed operation phase, and calculating the amplitude Q(1) at the 1x rotational frequency; and calculating Q_base(1) according to the collectedin conjunction with a fitted curve, and if Q(1) Q_base(1) + offset, determining that imbalance occurs, and obtaining an imbalance degree based on the difference therebetween. The detection method of the present invention is simple, accurate, and adaptable.