Coordination Control And Energy Optimization Of Microgrid Cluster

With the aggravation of global energy crisis and the exhaustion of fossil energy,energy conservation and emission reduction has become one of the current and future trends in the development of microgrid cluster.Due to the diversity of its components and structures,microgrid cluster system brings greater challenges to the coordinated control of distribution network.At the same time,due to the complexity of microgrid cluster control structure,how to safely and effectively solve the coordination control and energy interaction between each sub-microgrid within microgrid cluster,and between microgrid cluster and distribution network,so as to make microgrid cluster system run more safely,reliably and stably is a key issue that need to be solved urgently in microgrid cluster.In this thesis,based on the coordinated optimal control of microgrid,the coordinated control and energy optimization of microgrid cluster are deeply studied.The main research contents include the following aspects:(1)The principle analysis of distributed generators is carried out,and the power generation model and output power model of the wind turbine and photovoltaic,the state of charge model of the battery,the fuel cost model of the fuel cell and the diesel generator are established,which lay a foundation for the subsequent multi-objective optimization of microgrid cluster.(2)A hybrid hierarchical control structure is proposed,which integrates the advantages of centralized and decentralized control.Based on this structure,coordinated control of microgrid cluster is carried out,and multi-agent technology is used to achieve hierarchical control.According to the different needs and objectives of coordination and optimization in each layer,the control strategies of microgrid cluster in different operation modes,among sub-microgrid,between microgrid cluster and distribution network are put forward,and the control strategies of microgrid cluster in grid-connected mode are emphatically studied.(3)According to time-sharing electricity price strategy,the energy optimization strategies of microgrid cluster in peak,flat peak and low period are proposed,and on the basis of the optimization strategy,a multi-objective optimization mathematical model of microgrid cluster is established.The model aims at the lowest production cost(investment depreciation cost,operation and maintenance cost,fuel cost,interaction cost between microgrid cluster and distribution network,and interaction cost of sub-microgrid)and the minimum environmental impact cost of the microgrid cluster.Under the constraints of power balance and battery output,the maximum fuzzy satisfaction method is used to transform the non-linear multi-objective optimization problem into a single one.Tabu particle swarm optimization is used to solve the objective function optimization problem.(4)In order to verify the accuracy of the proposed coordinated control optimization strategy and the established microgrid cluster model,the simulation of the microgrid cluster is carried out.The economy and environmental protection of the whole system under the two operation modes of microgrid cluster multi-objective coordinated grid-connected and separated grid-connected are compared and verified.The results show that the optimization strategy and mathematical model proposed can not only better realize the coordination of production cost and environmental pollution,but also has a strong effect on cut peak and fill valley,which validates effectiveness and rationality of multi-objective coordination optimization of microgrid cluster.