Research On Super Capacitor Hybrid Energy Storage System Based On Microgrid

Microgrid is a microgrid system integrating power generation and distribution,including power supply,monitoring and protection devices,energy conversion devices and loads.Among them,the most used form of power supply is distributed energy.Through effective control of its storage system,its power fluctuation can be effectively reduced,and the adverse impact of grid connection on the large power grid can be reduced.Microgrid has two working modes:grid-connected mode and off-grid mode.In order to reliably improve the economics of microgrid,this paper uses a battery-supercapacitor(Super Capacitor,SC)hybrid energy storage system(Hybrid Energy Storage System,HESS),and analyzes its control strategy,and studies the microgrid in detail.The main content of the control strategy of the power grid in the grid-connected and off-grid mode is as follows:When the microgrid is connected to the grid,the fluctuation of the busbar voltage will have an adverse effect on the large power grid.HESS is used to stabilize the random variation of distributed energy sources to stabilize the fluctuation of the busbar voltage,thereby improving the grid-connection capability of the microgrid.In the traditional voltage and current double closed-loop control strategy,the sudden change of power will directly cause the DC bus voltage to fluctuate,which will increase the pulsation of the output grid-connected current and affect the power quality.In this paper,in the traditional grid-connected voltage and current double closed-loop control strategy,supercapacitors and battery current loops are added to reduce current pulsation when connected to the grid and improve power quality.And using MATLAB/Simulink simulation,the simulation results prove that the proposed control strategy can suppress the pulsation of grid-connected current and improve the quality of grid-connected power.When the microgrid is off-grid,the random changes of distributed energy sources will make the bus voltage unstable and unable to continuously supply power to the load.Therefore,the use of HESS stabilizes the bus voltage and increases the reliability of load power supply,thereby improving the stability of the microgrid off-grid.In the traditional control strategy,the battery’s response speed is slow,which will produce error power in the battery system and affect the stability of the DC bus voltage.This paper proposes a new control strategy to use the fast response capability of SC to compensate the error component and transient power of the battery.Thereby,the bus voltage can be stabilized more quickly,the battery voltage overshoot can be reduced,and the battery life can be prolonged.The simulation results prove that the proposed control strategy can stabilize the DC bus voltage faster and maintain the stability of the microgrid.Figure[47]table[3]reference[80].