Control strategy of DFIG and SVG cooperating to regulate grid voltage of wind power integration point

To better solve doubly-fed wind farms' voltage stability control problem with static var generator (SVG), this paper proposes and designs a reactive power regulation strategy based on SVG and doubly-fed wind turbines. To stabilize the voltage of the wind farm, SVG is preferred for reactive power compensation when the voltage fluctuates. After the voltage is stable, the reactive power output of SVG and the doubly-fed induction generator (DFIG) is adjusted according to the system state. The DFIG can output enough reactive power and meet the specified power factor conditions. The control mode adopts a real-time tracking mode to monitor the voltage of the control bus. In the model, comprehensive optimization indexes consider the maximum voltage offset, the time-consuming voltage to enter the stable range, the steady-state voltage deviation, and the average voltage offset in voltage fluctuation. The genetic algorithm optimizes the proportional-integral (PI) controller parameters of DFIG and SVG reactive reference values. DFIG and SVG have better response effects to voltage fluctuation than before optimization. Finally, the grid model of DFIG is built, and the simulation results verify the effectiveness and correctness of the proposed method. The cooperative control strategy of SVG and DFIG can adjust the voltage quickly and avoid the long-term reactive power flow between them.