Research On The Equalization Strategy Of Underwater Vehicle Power Lithium Battery Pack

With the vigorous development of the new energy industry,the power lithium battery pack has a greater demand in the market,and is not limited to the electric vehicle industry.The most important factor to consider in the use of power lithium batteries is the State of Charge(SOC)of a single battery,so that the SOC of batteries in the battery pack should be consistent.At the same time,in order to increase the stability and overall available capacity of power Battery packs,a Battery Management System(BMS)with balancing and collection functions is designed for the power system.Using BMS can effectively reduce potential safety problems of battery packs.The battery management system can implement data detection,security warning,energy management,and balance management.Balance management is the main function of the BMS.The use of batteries in series and parallel groups can solve the high voltage and high power requirements of the system.However,inconsistency will occur during the use of batteries.In order to solve this problem,it is necessary to conduct relevant research on the SOC estimation and balancing strategy of batteries.This paper introduces the function of BMS and its advantages and disadvantages.At the same time,as the management object of BMS,the working principle of terpolymer lithium battery is analyzed in detail.Then,the reasons for the inconsistency of lithium battery are expounded,and the methods to reduce the inconsistency of battery are studied.By analyzing the advantages and disadvantages of different equilibrium variables,the appropriate equilibrium variable is selected as the research object of this paper,which lays the foundation for the subsequent formulation of equilibrium strategy.Secondly,the SOC prediction method based on chaotic time series adaptive filter is adopted.The phase space reconstruction technology is used to input the reconstructed battery SOC time series into the adaptive filter,and the model parameters are constantly modified according to the current obtained data.The experimental results show that the algorithm can effectively improve the estimation accuracy,and the algorithm error accuracy is controlled at 0.6%.Then,in order to improve the available capacity of battery packs,battery SOC was selected as the equilibrium variable of the system.The balance topology based on transformer is selected as the main balance structure in this paper,and the balance control strategy based on cluster analysis is proposed.The available capacity of lithium battery pack using the designed balance control strategy is increased by 8.18%,which further proves the effectiveness of the balance strategy in this paper.Finally,the hardware circuit design and software process of the battery balancing system are introduced,and the balancing control strategy proposed by the system is verified by the design balancing experiment.The experimental results show that the balancing strategy can reduce the inconsistency of the battery pack and improve the capacity of the battery pack.