A Coordinated Voltage Control Strategy for Coordination of Wind Turbines Variable Mode control and OLTC in Distribution Grid

For distribution networks with dispersed wind power access, due to their limited voltage regulation resources and flexible and diverse access methods for dispersed wind power, voltages are more likely to be exceeded in the network. If the reactive power compensation device is installed, it will lead to poor economy. In this regard, this paper proposes a coordinated control strategy to improve the reactive power regulation capability of wind turbines and the voltage regulation using on-load tap-changer (OLTC). Firstly, the overall scheme of the coordinated control strategy is introduced: when the voltage of the distribution network exceeds the limit, the reactive power output under the maximum wind energy tracking (MPPT) control of the wind turbine is used for rapid voltage regulation; when the reactive power reaches the limit, it is temporarily sacrificed maximum wind energy tracking, using the reactive power maximization control strategy to increase the reactive power output of the unit; if the voltage is still not restored, adjust the tap of OLTC. Then, the reactive power and voltage control strategy of the dispersed wind turbine is given. Finally, the PSCAD simulation results show that the coordinated control strategy proposed in this paper has better played the advantage of coordinated control of dispersed wind turbines and OLTC, and enhanced the voltage regulation capability of the distribution network.