Load Restoration Optimization Considering The Effect Of Wind Power Participation On Power System Safety

The increasing scale of power systems,the increasing complexity of structures,and the increasing proportion of new energy sources have led to an increase in the risk of large-scale blackouts in the system.Therefore,it is of great significance to study the power system restoration problem after the blackout.The load restoration is the last period in the recovery process.The rationality of the load restoration plan will determine the system recovery time and economic loss.It is the main task of this period to develop a load restoration scheme that takes into account both load restoration and power system safety.With the improvement of wind power control technology and the increase of permeability,wind power can be used to provide power support for the system.On the basis of earnestly studying and drawing on existing research results,this paper studies the problem of load restoration optimization considering the impact of wind power participation on system security.(1)Aiming at the volatility of wind power output and the load of the node,the robust optimization model considering wind power and load uncertainty is constructed with the minimum time-step loss load as the optimization goal,so as to avoid the fluctuation of the variables affects the emergence of a steady state of recovery.By decomposing the model into the lower-level problem of traversing the worst external environment and the upper layer of verifying whether the recovery scheme satisfies the security constraints and optimizes the recovery scheme.The recovery scheme obtained by using this model has certain adaptability to uncertainty.The proposed method is validated by IEEE39 system.(2)Established a load node safety degree index to reflecting the degree of recovery load power on the system voltage,and put it with the load importance degree to constitutes the load equivalent weight.The conditional risk value method is used to describe the wind power output,and the corresponding reliable wind power output interval is obtained at a certain confidence level.Maximize the load restoration amount and minimum power flow entropy as the optimization goal,the load restoration optimization model of wind power system considering the power flow safety margin is constructed.(3)The IEEE39 system with wind power and Hebei regional power grid are used to verify the load restoration model considering the power flow safety margin.The results show that the load node safety degree index and the power flow entropy index are included in the optimization target set,which can improve the power flow safety margin and enhance the anti-interference ability of the system without sacrificing the load restoration amount.