Energy Management And Capacity Optimization Of Hydrogen Supported DC Interconnected Microgrid System

In recent years,the energy crisis and environmental pollution have become main factors restricting social development,making the development of renewable energy sources gain unprecedented attention.Hydrogen energy is clean,efficient,widely used,and in line with future trends.It has attracted more and more countries to pay attention to the utilization of hydrogen energy.Therefore,DC microgrid system based on hydrogen energy has become a new research topic.This thesis studies energy management and collaborative optimization of wind,solar,hydrogen,and storage systems in an off-grid DC microgrid,and constructs the basic model of the DC microgrid system.Then,K-means algorithm is utilized to extract three typical time series scenarios synchronously from wind power output,photovoltaic output and load data.In addition,the thesis simulates electric vehicles load based on Monte Carlo method.And analyzes the impact of distributed generation connection capacity and method on microgrid.Moreover,the thesis proposes the energy management strategy supported by hydrogen energy.Through bilevel programming model,the upper level takes the equivalent annual cost,total network loss and voltage offset as the optimization goal,and the lower level takes the loss of power supply probability and energy excess ratio as the goal,and fully considers the environmental benefits.Finally,the particle swarm optimization algorithm is used to find the best solution.The results show that the synchronization scenario reduction based on K-means can reflect the correlation between wind power/photovoltaic/load data,and can be used for pre-processing of data in microgrid planning and design.The proposed energy management strategy can make good use of the complementary characteristics of batteries and hydrogen energy systems,realize seamless switching and smooth power fluctuations.Although the DC microgrid system optimized by the bilevel particle swarm optimization is slightly insufficient in cost,it has higher power quality and reliability,and can maximize the use of renewable energy.Taking into account industrial demand,fuel cell vehicle development,and continuous cost reduction,the DC microgrid system supported by hydrogen energy has broad application prospects.