Closed-loop active power control of wind farm based on frequency domain analysis

Abstract

To further improve the wind power quality and stability, it is necessary to break the existing open-loop wind farm scheduling method and bring new strategies in both wind farm and wind turbine active power control. In this paper, a closed-loop active power control method is proposed based on the active power tracking dynamic characteristics of wind turbines, where the power fluctuations caused by the modeling errors and wind turbulence are isolated and suppressed by a proportional-integral (PI) controller. The PI controller parameters are obtained through the frequency domain analysis with bode diagrams. Then a frequency-domain aggregation and approximation method is proposed to establish the wind farm active power tracking model, and the wind farm-level controller is obtained similarly with the unit-level one but with an event-driven integral structure. Simulation results show the significant improvement and good robustness of the proposed controller.