Power Mutual Aid And Coordinated Operation Of Multi-microgrids

The increasing permeability of the distributed power supply in the medium and low voltage distribution network,the problems of the power quality,protection and economy of the distribution network will cause the scheduling and security stability of the distribution network to face enormous challenges.In order to better manage the distributed power supply and maximizes,its advantages microgrid is an effective technical means to introduce renewable energy into the power grid.Micro-grid can solve the problems of their own interal distribution power supply and form self management autonomous systems,but when a large number of microgrids is connected to distribution network,it is difficult to ensure efficient,safe and coordinated operation of multiple microgrids and distribution networks and the economic control of internal micro sources in various microgrids.First of all,this paper focuses on the impact of distributed power access on the distribution network voltage and network loss,When the heavy load of the distribution network,the voltage will fall.This paper adopts grid connected inverter and coordinated SVC to output reactive power make the voltage quality meet the qualified level.Through simulation example,the normal and heavy load situations are analyzed.results show that the coordinated SVC of the grid connected inverter can improve the voltage quality significantly and reduce the loss of network.Secondly,the mathematical modeling of distributed generation is made,includeng wind power generation model,photovoltaic generation model,micro gas power generation model and charging and discharging model of storage battery.In addition,a detailed analysis on microgrid dispatch are described and which is divided into microgrid connect scheduling and off-connect mode,based on the analysis of scheduling,this paper proposes multi-microgrid combined dispatching mode,the microgrid scheduleng is divided into the peak flat valley three scheduling periods,respectively expounds the different periods of distributed generation in microgrid,microgrid and microgrid,microgrid and distribution network power coordination scheduling problem.on the basis of the mathematical model of different distributed energy resources supply and the joint dispatching mode of multi-microgrids,a mathematical model of economic dispatch is established,which takes the minimum total cost of multi-microgrids system as the objective function.The solution method based on particle swarm optimization(PSO)is proposed.Finally,microgrid photovoltaic and wind power output and load were simulated.To verify the correctness of multi-microgrids scheduling strategy and model in this paper,two microgrids connected are selected for example anaiysis.Particle swarm optimization is used.Under the scheduling strategy of three periods in peak ping gu.Compared with the grid connected alone,the optimization results show that the coordinated network can significantly improve the economic performance of microgrids.it can improve the consumption of renewable energy,achieve power cooperation between microgrids in the different period,reduce the running costs of the system,and it can guide the orderly connection of different micro-grids to achieve energy coordination and energy exchange between different micro-grids,Besides,the influence of storage unit on the operating cost of microgrids was emphatically analyzed.Storage unit not only plays a role in valley filling,but also plays a significant role in improving the economic performance of microgrid.Study on the coordinated operation strategy between multi-microgrids system in this paper,The better economy of the multi-microgrids interconnected system is verified by an example simulation,To some extent,this scheduling strategy can guide the multi-microgrids into the distribution network orderiy and realize multi-microgrids power cooperation.