Energy Management Strategy Of Hybrid Energy Storage System Using Step-Up Battery In The Microgrid System

There are problems such as performance differences when the retired electric vehicle battery is used as a microgrid energy storage battery.In this paper,based on the research of hybrid energy storage composed of stepwise utilization of batteries and supercapacitors,the energy management of the microgrid is studied.A hybrid energy storage allocation strategy for hybrid energy storage in different operating modes in the microgrid is proposed.Based on the energy storage allocation strategy,a microgrid energy management strategy is proposed.Based on the construction of a microgrid energy management coordination strategy,the microgrid’s working mode is analyzed in detail,and the energy management strategies under various working modes are given.The main work of this article is as follows: First of all,the inconsistency of the power battery used in the ladder and the problems existing in the group are studied,and the method of modularized energy storage system using the battery in the ladder is designed.The control method of the energy storage unit’s power storage module is analyzed.In combination with the control method of the microgrid,an independent module control system is designed.According to the traditional equalization method,a better equalization effect can be achieved only when the initial SOC(state of charge)capacity is the same.Considering the capacity inconsistency of the echelon utilization power battery,based on the traditional equalization control,this paper studies the improvement and designs the improved SOC equalization control method when the capacity is inconsistent.Secondly,based on the hybrid energy storage composed of stepwise utilization of batteries and supercapacitors,a voltage droop control strategy is proposed.Based on the balance of power supply and demand,the power storage system is used to stabilize the power fluctuations of the microgrid.Based on the traditional droop control algorithm Based on the proposed hybrid droop control strategy based on hybrid energy storage SOC,a mathematical model of improved droop control strategy is constructed.The hybrid energy storage voltage droop control of the microgrid based on MATLAB / Simulink simulation software is based on the simulation model.The correctness of the next control strategy.Finally,based on the coordination control strategy of voltage droop method and integral droop method,the hybrid energy storage allocation strategy in different operation modes is adopted,and the energy management coordination strategy is designed based on the hybrid energy storage allocation strategy.On the basis of constructing the coordination strategy of micro grid energy management,the simulation research of the improved droop control method and the improved micro grid under three operating conditions is carried out by using Matlab / Simulink simulation software.The simulation model of the microgrid under three operating conditions before and after the improved droop control method is studied.It is shown that the improved microgrid energy management strategy of the droop method can achieve battery balance and prevent the battery from overshooting and overdischarging,thereby verifying the correctness and effectiveness of the microgrid hybrid energy storage power allocation and energy control strategy.