Frequency regulation control strategy of wind farms based on temporal and spatial uncertainty

Abstract

The Frequency regulation capability of a double-fed induction generator (DFIG) in a large wind farm is influenced by its operating state and installation position, as well as the wind speed (size and direction) at which it is located, resulting in temporal and spatial uncertainties. First, to simplify control difficulty and optimize frequency regulation increment allocation, model predictive control(MPC) and k-means clustering method are used for spatial optimal grouping of DFIG in wind farms based on the uncertainties of DFIG installation location and wind direction. Second, a timing coordinated control strategy is proposed based on the uncertainties of the DFIG operation state and wind speed. The strategy allows the DFIG to enter and exit the frequency regulation system based on wind speed, active power increment, and sustainable time and then reduces the negative effect of the DFIG exiting the frequency regulation system. Finally, based on temporal and spatial optimization, a coordinated control strategy based on temporal and spatial uncertainties is proposed to optimize the overall frequency regulation capability of wind farms. Simulation examples show that the time–space coordinated control strategy treats each group as an independent DFIG control, which not only simplifies the control problem but also fully utilizes the DFIG frequency regulation capacity and effectively improves the system frequency characteristics.