Power fluctuation evaluation of large-scale wind turbines based on SCADA data

The random fluctuation of wind is the basic factor causing the power fluctuation of wind turbines. On the basis of the relationship model between wind and power, and considering the influences of wind speed fluctuation and wind direction fluctuation on power fluctuation, a novel fluctuation coefficient of wind speed, fluctuation coefficient of wind direction and the comprehensive influence factor are defined. The one-dimensional (1D) evaluation models of wind speed fluctuation to power fluctuation, wind direction fluctuation to power fluctuation and the 2D evaluation model of wind speed and wind direction fluctuation to power fluctuation are presented. The operating process of wind turbines is divided into three regions: the constant region of power coefficient, the transition region and the constant power region. In the constant region of power coefficient, wind speed fluctuation is the main factor affecting power fluctuation; wind direction fluctuation has little effect. In the transition region and the constant power region, both wind speed fluctuation and wind direction fluctuation have little effect on power fluctuation; especially in the constant power region in which power capture is limited by the pitch control technology, power fluctuation is not affected by wind speed fluctuation and wind direction fluctuation.