Research On Multi-time Scale Energy Optimization Of Independent Micro-grid

Micro-grid is a kind of modern smart grid with new energy sources.According to the study,compared to its direct integration,renewable energy incorporated into the power grid through the micro-grid can largely alleviate the impact on the stability of power supply.As a strong support of the traditional power grid,micro-grid has reduced a lot of power outages due to the failure of large power grid.The practical application shows that the micro-grid can make full use of local natural resources scattered,alleviate environmental pollution and the shortage of fossil energy.In addition,the micro-grid can also protect the power supply of large power grids in order to meet the diversification of demand for electricity.Based on the above advantages,more researches are focused on the micro-grid.The independent micro-grid is a combination of distributed power supplies,energy storage devices and electrical loads.After that,an independent and controllable system can be formed through effective energy supply configuration.As an important support for users in remote areas and island area,effectively improve the reliability of power supply.Because of the lack of reasonable scheduling of renewable energy sources in the independent micro-grid,there is a serious problem of "abandoning the wind and abandoning the light",so it is important to solve the problem of increasing the utilization rate of renewable energy.Therefore,based on the normal operation of micro-grid,this thesis focuses on the energy optimization of independent micro-grid.First of all,this paper analyzes the background of micro-grid technology,the definition and research results of micro-grid in the world.Then,this paper introduces the general structure of micro-grid,its operation mode and the basic characteristics of the structure.Three kinds of control technologies commonly used in micro-grid system are studied,and the protection methods are analyzed for each part of the system.The difference between micro-grid and large power grid in energy management is introduced.According to the definition and research status of its energy management system,the potential value of micro-grid research is analyzed comprehensively.In this thesis,we build an independent landscape micro grid system to supply power to users in the remote areas,combined with the local natural conditions.The photovoltaic arrays,wind turbines,lead-acid batteries and diesel generators are studied and their main working principles are introduced.Finally,the mathematical model of the distributed generators is established and the constraints are analyzed.In order to guarantee the stable operation of the independent micro-grid,this paper proposes a multi-time scale optimization energy scheduling strategy with dynamic characteristics.Finally,based on an independent micro-grid optimization example,the structural characteristics of the independent micro-grid are studied.After the analysis of the mainstream optimization algorithm,it is determined that this paper uses the particle swarm optimization algorithm.Then,the idea of particle swarm optimization is introduced,and the core connotation and optimization principle of particle swarm algorithm are analyzed.According to the mathematical model of distributed generators,energy optimization strategy,objective function and constraint condition,the second class optimization analysis is carried out.The optimal combination of each distributed generators of the micro-grid system is selected by using the algorithm.The feasibility of the micro-grid energy optimization strategy is analyzed and summarized.