Research On Power Coordination Control And Economic Operation Strategy Of Low Voltage Microgrid

In recent years,with the transformation of energy structure,countries have paid more and more attention to the development and application of microgrid.The microgrid system is mainly composed of distributed power supply,energy storage system,load and its central controller,and has the advantages of energy coordination and economic operation.However,there are many types of distributed power generation units,and different micro-sources have different power generation characteristics and work in a low-voltage level.In order to meet the requirements of large-capacity distributed power supply access,reliability of power supply quality,system economic operation,and comprehensive energy efficiency,multiple low-voltage single-micro network systems need to be combined into a low-voltage multi-micro network system.Energy coordination and economic operation strategies are used for energy allocation and management.Therefore,this paper has carried out related research on micro-grid power coordinated control and economic operation strategy.The main work is as follows:Firstly,this paper analyzes and mathematically models the power generation of distributed power generation units(photovoltaic power generation systems,wind power generation systems,diesel engine power generation systems)and energy storage systems in microgrids,and builds corresponding simulation models.At the same time,comparative analysis of distributed power energy conversion control methods and typical control strategies of microgrids.And carry out simulation analysis.Secondly,combined with the multi-micro network laboratory platform of our school,the research and design of the three-layer coordinated control framework,completed the hierarchical function definition and control strategy analysis;At the same time,in view of the problem that the reactive power cannot be equally divided in the traditional droop control,this paper proposes an improved droop control strategy based on the common load side voltage feedback.The strategy is modeled by the small signal analysis method,which provides a theoretical basis for system parameter setting;The MATLAB/Simulink simulation is used to verify the reactive power distribution relationship of this paper and improve the power quality of the microgrid.Thirdly,this paper studies and analyzes the economic operation strategy of the laboratory microgrid system from the two modes of island and grid connection,and establishes the objective function and the corresponding constraint condition processing method under the corresponding mode;At the same time,an improved particle swarm optimization algorithm is proposed and compared with the traditional particle swarm optimization algorithm.The experimental results verify the superiority of the improved particle swarm optimization algorithm.Finally,the structure and software system design of the multi-micro network experiment platform of the university are introduced.At the same time,the experimental verification of the energy coordination control strategy in the island mode and the grid-connected mode of the multi-micro network platform is carried out.The experimental results show the effectiveness of the overall system coordination control strategy.