The Research On The Design And Control For Main Circuit Of Energy Storage System

Now the shortage of energy and environmental pollution have been seriousproblems.The conventional non-renewable energy such as coal,oil and natural gas,notonly is limited,but also can cause serious environmental pollution.Development andutilization of wind energy in large scale is a important means to resolve energy andenvironmental issues.However,output wind power accessing to grid becomes randomand fluctuation due to the uncertainty of natural wind,which will bring seriousnegative impact to the grid.Energy storage system which adjusts output power fastand flexiblly can stabilize power of fluctuation effectively.Therefore,the research onthe operation and control of storage device in wind farm becomes necessary to reducethe negative impact upon the grid caused by fluctuation of wind power.A main circuit of charge and discharge of energy storage system is proposed toovercome the problem of intermittent and fluctuation of grid-injected power. Thework of the main circuit of energy storage system is showed and the unitarymathematical models of intergreted Buck-Boost and VSC are established with theVRLA as the storage component in this paper. Also the parameter design principle ofthe inductance is discussed under the premise of the satisfaction of the norm of thecurrent fluctuation in the circuit of Buck-Boost.The method of stationary periodcomparison is used in the circuit of Buck-Boost to achieve the constant of power, andthe accurately feedback-linearization control strategy is used in thegrid converter VSC to achieve the constant of the voltage of DCrespectively.Simulation experimental platform of energy storage system is set up,andexperimental results verify the feasibility of the control strategy for energy storagesystem and the validity of the design of main circuit parameters. Experimentalplatform of energy storage system is set up,and experimental results are the same withthe results of simulation.This paper based on the mathematical model of VRLA batteries is presented forthe calculation method of the residual capacity. With the TMS320LF2812A of TIcompany as the core, this paper realizes the monitoring for the voltage, current andtemperature of the battery.The voltage of the battery group is detected by inspection method, which can reduce the cost and system redundancy. It uses a temperaturesensor-DS18B20to detect the battery temperature, wich has small volume and highprecision. The PC can display the VRLA state, and also can alarm in real time. Theactual operations show that the monitoring system is flexible, accurate and can keep along-term stable operation.