Research On Flexibility Transformation Strategy Of Coal-fired Units Considering Wind And Solar Power Consumption

China’s power supply is mainly coal-fired power,but the flexibility of most thermal power units is poor,which affects the consumption of wind and solar power.In order to improve the flexibility of the power system,coal-fired units need to be flexibly transformed.The flexibility transformation of coal-fired unit is a complex project,and it is necessary to select an appropriate transformation strategy to ensure the economy of the transformation.Therefore,an appropriate flexibility transformation strategy is the key to realizing the value of unit flexibility transformation.The research contents and conclusions of this paper are as follows:First of all,this paper summarizes the researches of domestic and foreign scholars on the flexibility transformation of coal-fired units in recent years,and finds that most of the researches are based on the perspective of cost to make transformation decisions,while the research to determine the transformation plan of coal-fired units from the perspective of the power system as a whole is relatively,and even the researches that can take into account both economic benefits and scenery consumption are still in the blank stage.Therefore,this paper chooses to start from the cost point of view,and constructs a flexible transformation planning model for coal-fired units considering wind and solar power consumption.This model takes the minimization of the total cost as the objective function,not only considers the economics of the flexible transformation of thermal power units,but also introduces the consumption of wind and solar power into the research to provide guidance for the transformation and decisionmaking of coal-fired units.Secondly,the constructed model is decomposed by the Benders decomposition method to increase the solution efficiency.The original problem is decomposed into 1main investment problem and 12 operating sub-problems,and then through the iterative solution of the main problem and sub-problems,the original problem can be obtained.In addition,considering the instability of wind and solar power output,the agglomerative hierarchical clustering algorithm based on the shortest distance method is proposed to cluster the characteristics of wind and solar output,and the division principle of the scenario is given to obtain the wind and solar output in different scenarios.Finally,an example is introduced,and two typical wind and solar scenarios are described.The Matlab platform is used to solve the model under different scenarios,and the validity and applicability of the model are verified.The results show that when two 200 MW units and one 300 MW unit participate in the flexibility transformation,the optimal transformation strategy is obtained,and at this time,the total cost is the lowest,and the wind and solar energy consumption is the largest.In addition,this paper also analyzes the effect of flexibility transformation of coalfired units.The results show that the model can realize the efficient consumption of wind and solar power on the basis of meeting the power demand and the economy of flexible transformation,and it is suitable for finding the optimal solution under various parameter settings;Reasonable unit flexibility transformation can also further reduce the total cost,optimize thermal power operation,and alleviate the phenomenon of abandoning wind and solar power;Reasonable wind and solar subsidies can stimulate the enthusiasm of coal-fired units to participate in flexibility transformation,and can also promote the consumption of wind and solar power,to provide reference for the decision-making of enterprise flexibility transformation.