Research And Design Of Marine High Capacity Lithium Battery Management System

Compared with the traditional lead-acid battery,the lithium battery has numerous advantages,such as no memory effect,high energy density,low self-discharge rate,higher safety performance and it can meet the requirements for the energy storage system better.At the same time,with the continuously reduce of the price,the lithium batteries can be used to further promote on board.But during the work process,if over-charge or discharge,temperature is too high or too low etc.This will affect the performance of lithium battery energy storage unit,even damage it.Besides,a high-voltage and high-capacity energy storage unit is needed to meet the requirements of energy storage system on board,we call this “Barrel Affects”.In a word,a BMS is necessary for lithium battery energy storage system on board,there is also a rule in “solar photo voltaic system and lithium iron phosphate battery system inspection guide” released by China Classification Society in 2014.This paper is mainly research on marine lithium battery energy storage system,and completed the software and hardware designment of battery management system based on SOC estimation and diagnosis methods of system faults.Firstly,by testing the OCV-SOC curve and the available capacity of lithium battery at different discharge rate,this paper analysis the characteristics of lithium battery,estimate the SOC value according to ampere-hour integral and the open circuit voltage.Then correct the ratio characteristics of lithium battery by rate correction factor,and correct SOC value by open circuit voltage in the end of charge and discharge period.Secondly,by analyzing the characteristics of the energy storage device of the new energy system for ship,this paper complete the overall design of the marine energy storage system.Considering the sampling precision,layout and monitoring of real-time,a designment of the battery management system is completed based on distributed topology.Thirdly,by researching the fault phenomena and causes of the battery energy storage system,a solution of faults was maded based on the characteristics of cell.Design a remote control system based on 4G network and the B/S structure for the convenience of maintenance on ship and the support of experts.Finally,this paper complete the software and hardware design of the management system of marine lithium battery energy storage device according to the function demands to achieve the function of charge and discharge management,temperature control,residual capacity estimation,safety protection of lithium battery storage system,and there is also a function that real-time monitoring and remote fault diagnosis.