Study Of Energy Storage System Management And Control In Micro Grids

The micro-grid technology solves the technical defects of traditional distributed generation,and promotes the development of sustainable new energy generation technologies. Energystorage system is an important part of the micro-grid system, it can solves some unfavorablefactors such as the system fluctuation which are from the traditional DG output powerimbalance caused, and significantly improves the stability and reliability of micro-grid.Energy storage system research is focused on energy management and control technologies,as they affect the energy storage device life cycle, security and economy.This subject focuses on Lead-acid battery storage system modeling, state of chargeestimation and the control strategy of bi-directional DC-DC converter.The main researching work is shown as follows:(1) Analysis various lead-acid battery’s model, choose the equivalent model make it closeto the real battery internal structures. Choose the RC equivalent model and its nonlinearstate-space description.(2) Compared with the traditional methods, to estimate state-of-charge (SOC) of batteriesbased on state observer techniques make less detection for facilitating application in astand-alone PV power generation system. However, the usual EKF algorithm for stateobserver in the nonlinear model is less superior filtering algorithm, and sensitive to initialvalue, the filter easy to diverge. In this paper, the evolution of hybrid particle filter algorithmis proposed and experimental results show significant improvement in accuracy and stability.(3) The topological structure and working characteristics of Bi-directional DC-DCconverter and energy storage battery charge and discharge characteristics of the controlstrategy were analyzed in this paper. Study the control strategy of the converter in differentoperation mode the MATLAB simulation results show the strategy correctness.(4) According to the energy flow characteristics of the energy storage system, thecorresponding working mode software process was designed. Energy storage charging anddischarging experimental verification was done in experimental platform of the micro-gridwhen gridding. The result of experimental run was analyzed at last.