Voltage And Frequency Control Strategy Of The Power System With High Penetration Of Wind Generation

Wind generation’s characteristics, irrationality of wind power development patterns and weakness of the grid structure have caused many problems on wind power consumption. This work aims to study coordinated voltage control strategy for wind farm clusters and frequency adjustment strategy for system with high penetration of wind generation.For voltage control,the active power fluctuation caused by wind speed fluctuation is the fundamental reason of voltage problem,so it’s necessary to study corresponding voltage control strategies for different wind conditions.Considering tremendous changes of wind farm clusters’ running status under extreme wind conditions and limited closed-loop control capability of reactive power continuously adjustable equipment, a corresponding voltage control strategy is proposed, which can provide preventive voltage control and corrective voltage control for conditions before/after extreme wind speed through ultra-short-term wind power prediction. By comparing the examples, limitations of the traditional closed-loop control method and superiority in voltage control and wind farm’s internal feeder voltage balance through control strategy in this paper can be verified. It provides an effective method for solving the nigh voltage off-grid accident under extreme wind conditions.For frequency adjustment,a control strategy for short-term frequency support of wind turbines is proposed,which enables the wind turbines to offer temporary and stable frequency support over varying wind speed and large wind speed range. Then,based on the analysis of the capabilities of wind turbines, the strategy of energy storage used for wind turbine adjusting frequency reserve and improving secondary frequency drop is proposed,which can improve the dynamic characteristics of the system frequency. The coordinated control strategy of wind turbines and energy storage is based on MATLAB\Simulink of IEEE Realiabilty Test System simulation system.The superiority of energy storage on helping wind turbines in frequency adjustment is proved.