Kesearch On Black Start Of Micro-Grid With Hybrid Energy Storage System

With the increasing degree of electrification in contemporary society,Electric power resources have become an indispensable factor in human production and life.The frequent occurrence of major power outages in the world reminds us that human beings need to reduce economic and property losses as much as possible after major power outages.How to restore power supply in the region within a short period of time and protect important loads has become an urgent problem to be solved.As the first step to restore power supply quickly after power system breakdown,black start has become the research focus of power system automation in recent years.With the continuous development of energy storage technology and power electronics technology,the hybrid energy storage system with the advantages of supercapacitor and battery has the characteristics of high energy density and long duration.The hybrid energy storage system has the condition of black start power supply.The use of hybrid energy storage system to deal with the power failure of the power grid ensures the reliability of the black start of the micro-grid to the greatest extent,greatly reduces the time consumption of the black start of the micro-grid,speeds up the restart speed of the micro-grid,and widens the application field of the hybrid energy storage system.Firstly,this thesis compares and analyzes the black start ability of several major micro-sources in the micro-grid,taking feasibility,reliability,start time and other aspects as the comparison basis.According to the self-start ability,the selection scheme of micro-sources in the black start process is determined.The analysis results show that the wind and Pv power sources without energy storage coordination do not have self-starting ability,and the hybrid storage system and microturbine can be used as the micro-grid black starting power source because of their self-starting ability.Secondly,in this thesis,the voltage equalization of a hybrid energy storage system consisting of a supercapacitor array and a battery pack is studied.To solve this problem,a new voltage sharing control method isproposed to realize the voltage balance of each energy storage unit.Matlab/Simulink was used to carry the grid-connected model of the hybrid energy storage system,and the reliability of the system was verified by simulation.Thirdly,this thesis elaborated the working principle and working mode of the power conversion device,and built the simulation model of the control module with Matlab/Simulink.The simulation results proved the feasibility of the control of the power conversion device.Finally,the black start process combined with serial and parallel and an improved micro-grid topology structure are adopted to build a hybrid energy storage system containing supercapacitors and a micro-grid Matlab/Simulink simulation module of micro gas turbine.The simulation verifies the feasibility of the black start process.