Research On Hterarchical Coordinated Control Strategy Of Active Power On Clustered Wind Farms Under Wind Curtailment Condition

In recent years,the wind power industry in china has maintained rapid growth.Under the guidance of "building large base and integrating into large power grid",wind power in china has developed from small-scale decentralized development to large-scale centralized development,local consumption to long-distance and high-pressure transmission.However,some contradictions gradually highlighted at the same time,because the development of wind power is too concentrated,the construction of power transmission channel is lagging behind and the system peaking capacity is insufficient in some areas,the integration and consumption of wind power is difficult,and the problem of wind curtailment and power rationing is more and more serious.In the case that the problem of wind curtailment can not be solved effectively in the short term,how to coordinate the active power output of wind farms and units of clustered wind farms to optimize the output tasks is an urgent problem to be solved.The research work of this field has a realistic significance to improve the acceptance ability of wind power,reduce the loss of abandoned wind power and enhance the level of operation of clustered wind farms.Firstly,this paper analyzed the fluctuation characteristics of wind power.The fluctuation and probability distribution of wind power on wind farm,clustered wind farms and the province was studied by using statistic index of the mean,standard deviation and first order difference based on the measured data.On this basis,then the main causes of wind curtailment and power rationing was analyzed from three aspects which are the influence peaking of power grid,the ability of acceptance of wind power and the limit of transmission channel;Then,based on the analysis of the active power dispatching requirements and operational control of wind farms,this paper studied the active power allocation strategy of wind farms.Three kinds of allocation strategy model are established,to assign active power output of each wind farm during power limitation period.The feasibility and superiority of the proposed strategy is analyzed by calculating the total output of clustered wind farms and the corresponding abandoned wind power,to provide an optimization scheme for the dispatch and regulation of wind power.Finally,this paper proposed a hierarchical coordinated control strategy on active power of clustered wind farms under wind curtailment condition,Based on the idea of hierarchical partition,a new two-layer control model for active distribution of clustered wind farms is established.Through the coordinated control of the active power of wind farms and units of clustered wind farms,the wind power limit can decompose and the active output task can implement step by step.The model is solved by the improved genetic algorithm to optimize theallocation of the output tasks of each wind farm and unit.The feasibility and effectiveness of the proposed strategy is verified by an example of clustered wind farms in Northeast china.The results show that the proposed strategy can achieve the optimal allocation of the output tasks between the wind farms and the units in the field,and improve the wind power accommodation capacity of power grid and the economy of the system operation.