2KV·A Lithium Battery Discharge Battery Management System

At present,with the increasing demand for energy,the reserves of fossil energy are becoming less and less.Although the utilization rate of solar energy,wind energy and other new energy sources is increasing year by year,there are still instability and intermittency,which must be solved through energy storage containers.The reasonable application of large-capacity energy storage containers can effectively solve the problem of insufficient electric power in some economically underdeveloped areas in central and western China,greatly relieve the pressure of the state grid,and also provide an effective way for the storage of new energy.Now,large-capacity energy storage containers are basically constructed by a single lithium battery.However,all the small changes in the group of lithium batteries will lead to the deviation of the battery’s macro parameters,which will lead to the differences between different batteries,making the life of the battery pack shorter than the life of a single battery,easily causing danger.In view of this situation,this paper designs a semi-distributed lithium battery management system.After reading a lot of materials and comparing various schemes,a modular battery management system with DSP chip TMS320F2812 as the microprocessor is designed.The system adopts semi-distributed structure to manage and control the battery pack reasonably.The whole system can collect the voltage,current and temperature of the battery pack accurately.At the same time,based on the average voltage of the battery pack as the control strategy,a bidirectional flyback equalization module is designed to realize the balance of the remaining capacity in the battery pack in a fast and efficient way.This paper starts with the introduction of the research status of battery management system at home and abroad,and compares and analyzes the commonly used parameter collection methods of voltage,current and temperature.Based on the 1tc6803-1 chip,this paper designs a collection module,which can accurately collect the voltage and temperature parameters of the battery pack.At the same time,the current current data of the battery pack is accurately collected through the absolute value sampling circuit.Through the comparison and analysis of the active balancing topology,the bi-directional flyback topology was selected to realize the battery pack balancing,and two complementary driving signals were generated based on the driver chip LTC3300 to realize the normal operation of the topology.At last,the SOC estimation method analyzed in this paper is simulated by MATLAB.The experimental results show that the battery management system can accurately collect the voltage of each individual battery with an error of less than 10mV,A total current error of less than 150mA and temperature data error of less than 2.5℃ when the battery pack works under the condition of 2KV·A inverter.