Research On Power Distribution And Economic Scheduling Strategy Of Microgrid Cluster

The microgrids are interconnected to form a microgrid cluster system.Compared with a single microgrid,the microgrid cluster system not only enhances the reliability of microgrid power supply,but also realizes the energy mutual aid between microgrids through the energy dispatch of each sub-microgrid and distributed generators in the system.Although the microgrid cluster system has the advantages of being safer,more reliable and more stable,the structure of the microgrid cluster system becomes more complex after the interconnection of each microgrid,which greatly increases the difficulty of energy dispatch and economic operation of the microgrid system.Therefore,how to realize the optimal power allocation and optimal economic dispatch of the microgrid cluster system is one of the urgent problems to be solved.The power allocation and economic dispatch of microgrid cluster systems have been studied.The complexity of the system structure makes it difficult to achieve optimal power allocation to each microgrid when optimizing the scheduling of a microgrid cluster system.Meanwhile,the transaction mechanism among sub-microgrids in the operation of microgrid cluster system is complicated,and it is difficult to make full use of the renewable energy generators output in each microgrid,which makes it difficult to ensure the economy of microgrid cluster system.In order to achieve the optimal power allocation and optimal economic operation of the microgrid cluster system,this paper considers the energy mutual aid among microgrids,the power loss,the uncertainty of renewable energy generators output,the load fluctuation,and the real-time trading tariff between users and power suppliers in the operation process of the independent microgrid cluster system.Aiming at the economic optimization of the microgrid cluster system operation,related research has been carried out from two aspects: bi-level optimization and cooperative game consistency optimization strategies.The specific work is as follows:Firstly,the current status of domestic and international research on the optimal scheduling of microgrid cluster systems is summarized.The problems in the operation of the microgrid cluster system are explained and the correlation between each microgrid and the microgrid cluster system is introduced.Subsequently,the system structure of a microgrid cluster system in islanded operation is analyzed,and the mathematical model of the consistency algorithm and its application in a multi-intelligent system are studied.Secondly,bi-level optimal scheduling strategy for islanded microgrid cluster systems based on optimal power flow and consensus algorithm.The islanded microgrid cluster system is divided into upper and lower layers.In the upper layer,each microgrid is abstracted as a virtual power supply or virtual load based on the predicted power output of the microgrid.Meanwhile,with the goal of minimizing the network loss,the problem of energy mutual aid and power distribution between microgrids is transformed into a problem of solving the optimal power flow.In the lower layer,with the upper layer power allocation scheme as the constraint,the uncertainty of the wind/solar power output and load fluctuation are considered.Subsequently,an optimal scheduling model for controllable distributed generators within the microgrid is developed based on an equal cost increment rate consistency algorithm,and the ‘plug and play’ of the controllable power supply is also realized.Finally,an independently operating microgrid cluster system is used as an example to verify the economy and reliability of the strategy.Finally,cooperative game consistency optimal scheduling strategy for microgrid cluster system considering flexible load.Considering the operating indicators such as power loss and flexible load demand within each microgrid during the operation of the microgrid cluster system,and the interests of the user side and the power supply side,a real-time trading tariff model between the user and the power supply is constructed with the goal of maximizing the benefits of both the user and the power supply.Furthermore,considering the energy mutual aid among microgrids,the cooperative game optimization scheduling model of multiple microgrids is established with the objective of minimizing the operation cost of the microgrid cluster system.Subsequently,the Lagrangian function is introduced,and the equal incremental rate consistency algorithm is used to obtain the optimal solution of the cooperative game model.Meanwhile,the equivalence of the converged consistency variables and the real-time trading tariff is proved,and the benefit distribution of each microgrid is accomplished using the Shapley value method.Finally,an independent microgrid cluster system is used to verify the effectiveness and reliability of the method.