Research On Micro-grid Energy Management System Of The Island

Micro-grid is a new type of power system,it can make full use of local scattered natural energy,as well as solve the problem of the impact of large power grid due to the distributed generation and also solve the problem of resource depletion and environment pollution in today’s society. As a complementary energy of the Grid,it can not only meet the demand of the different requirements of the users on energy services,but also can improve the Grid’s ability to cope with sudden disasters.Based on the above advantages,micro-grid technology was attached great importance to sice it was proposed,and obtained the great development.So far, the number of distributed generation units contained in the micro-grid systems is being more,at the same time the kinds of distributed generation units contained in the micro-grid systems tend to diversify.All this result in the micro-grid system is becoming more and more complex.How to manage the micro-scorce in the system,make the economy of micro-grid reached a higher level,become an important factor which restricting the development of micro-grid technology.Micro-grid energy management system is the technology,which to coordinate and control the distributed generation in the system,as well as to realize the economic and reliable operation.And the main contents of this paper are described as follows:Firstly,this paper analyzes the social background of micro-grid and the development status at home and abroad,points out that micro-grid has an infinite potential for future development and improvements.Recommend basic structure of the micro-grid domestic and overseas,and analyze the basic characteristics of the structure of the micro-grid.Based on this this paper proposes a basic structure of the micro-grid on an island,which includes photovoltaic cells,wind turbines,lead-acid batteries and diesel generators,analyze the operating principle of each micro-source in the system and establishes the output power models of each distributed generation unit in the system.Given the control strategy of the distributed generations in the established system.Secondly,Analysis the difference between micro-grid and large power grid energy in the management,presents the definition of micro-grid energy management system. Introduce the control strategy of micro source in the system,as well as the control strategy of micro-grid.Master-slave control strategy is chosen as the control strategy for micro-grid of island. Summarize the methods for Energy scheduling of the micro-grid.According to the characteristics of the micro-grid of island,provide energy scheduling for Micro-grid of the island.Thirdly,establish a multi-objective dispatch model for the Micro-grid we has already used,which includes three optimization function:system operation quality is high,system operation cost is low;environment friendly degrees high.Accoding to the characteristics of each micro source within the Micro-grid,and the conditions that can make the Micro-grid operate safely, stablely and economicly,given the constraint for the dispatch model.Analysis of the characteristics of Micro-grid energy management dispatch model,chose the Particle Swarm Optimization(PSO) algorithm as the solution,present the basic steps of PSO to solve the problem.Finally,provide the simulation model for Micro-grid according to the established micro-grid structure for island given before.Combined with the output power models of each distributed generation unit,the control strategy of the distributed generations,dispatch model for the Micro-grid,the constraint for the dispatch model,and PSO algorithm, give the best combination unit for all seasons typical day and the transactions between the large grid and Micro-grid.Then we can verify the Micro-grid energy scheduling strategy proposed in this test and the feasibility of optimization algorithm.