Research On Modeling And Management Of Series Connected Battery Bank

With the promotion of renewable energy strategy of China,renewable energy generation technology has become a new concentration in the research field of power system.Renewable power is usually converted by power electronic converter and stored in energy storage device,then supplied to load or integrated into the grid.At present,series-connected battery packs are still widely used as energy storage medium in large-scale energy storage systems.Therefore,modeling and efficient management of energy storage battery packs has become an important research direction.This paper studies the construction of accurate and reliable battery management system(BMS).The BMS is studied and discussed from three aspects: battery modeling and simulation,battery state of charge(SOC)estimation algorithm,BMS hardware architecture design.Firstly,on the basis of reviewing the BMS,the working principle of lead-acid batteries is expounded.The improved PNGV model is used to model the batteries.The identification method of each parameter in the model is obtained through analysis.Combining with the test data,the battery model with variable parameters is established.Then,the variable parameters are substituted for simulation.The feasibility of the model is proved.Secondly,based on the improved PNGV model with variable parameters and the extended Kalman filter algorithm(EKF),different variables in the battery model are extracted as EKF states and outputs respectively.The SOC estimation simulation is carried out using the current of actual experimental data as input.The SOC estimation error is small,which proves the feasibility of the SOC estimation algorithm.Finally,according to the demand characteristics of the battery management system,the basic hardware framework of the distributed battery management system is proposed,and the requirement analysis and circuit design are carried out for each basic sampling module in the framework.At the same time,after considering the design requirements of the sampling module,the MCU is selected.The appropriate micro control chip is connected with the working mechanism of the hardware circuit,and the control program is designed.