Research On Coalition Formation Method Of Power Trading For Microgrid Group In A Distribution Network

With the wide application of renewable energy,the number of microgrids in distribution network is increasing,forming a microgrid group among each other.Because of the diversity of decisions and complexity of the market in the power trading process,how to realize the coordinated operation between microgrids and distribution networks,as well as among microgrids,has become the key to study the power trading problem of microgrid group.In recent years,the collaborative operation power trading method for microgrid group based on coalitional game theory has shown its application potential,which can effectively improve the enthusiasm of microgrid to participate in coalition and transaction flexibility.However,it is difficult for existing methods to obtain a better stable solution in the coalition structure formation process of microgrid group,and the solution results are not unique.Therefore,it is of great significance in theoretical research and practical application to further study the coalition formation algorithm of power trading in a microgrid group based on coalitional game theory.This thesis takes the microgrid group in the distribution network as the research object,studies the coalition formation method of power trading for microgrid group based on the coalitional game theory.And a coalition formation algorithm considering the elements of coalition utility calculation and allocation,coalition merging and splitting process,and coalition reconstruction process is proposed,based on the reconstruction process to improve the quality of problem solving.On this basis,a simulation software of microgrid group coalition formation is developed.Specific work is as follows:First of all,according to the microgrid group structure and microgrid transaction process,a power trading model of microgrid group is established,and the trading advantages among microgrids are analyzed.Based on the coalitional game theory,the formation scheme of coalition structure for microgrid group is designed,which provides the basis for the subsequent research.Secondly,in order to calculate the coalition utility,a transaction matching method based on distance for buyers and sellers within a coalition is proposed,and a distance limiting coefficient is designed to restrict the coverage of coalitions,so as to improve the solving efficiency.Thirdly,taking into account both fairness and efficiency.Shapley value method is used to allocate the coalition utility to each member.Finally,combined with the above research content,a reconstruction process based coalition formation algorithm is designed comprehensively,the coalition structure update granularity is subdivided,so the solution space is fully explored for better solution quality,and the stability of the coalition structure is analyzed theoretically.Then,in order to verify the effectiveness of the proposed algorithm,simulation experiments are carried out by generating specific problem instances and large problem instances to analyze the solving quality and efficiency.The simulation results show that the solution quality of the proposed algorithm is better than that of similar comparison algorithms,and the average utility of microgrid and the participation proportion in coalition are both improved,which demonstrates the effectiveness and superiority of the proposed algorithm.Finally,aiming at the theoretical research and application requirements of the coalition formation problem of power trading for microgrid group,based on the three layer architecture with user layer,application layer and data layer,the simulation software is designed and developed to provide relevant personnel with user information management,problem solving,project file management and other functions.The effectiveness of the software and the application potential of the proposed algorithm are demonstrated through running results.