Research On The Equalization Of LiFePO4 Series Battery

LiFePO4 battery has been increasingly widely used in production and people’s social activities for its characteristics high energy density, no memory, large charging and discharging current.LiFePO4 batteries are usually connected in series to provide a high voltage in certain conditions. When batteries are connected in series to use, because of factory processes, working conditions or some other factors, there will be inconsistencies between the cells and they will exacerbate, which will reduce the whole batteries’life and performance, deploying equalization system can significantly reduce these inconsistencies in use process, it can increase the life of the whole batteries.The paper analyzes the research status of LiFePO4 batteries in depth, explains the basic working principle of LiFePO4 battery, the internal characteristics of the battery. This paper analyzed the results which measured by charging and discharging experiment. By comparing some classic equalization circuits of balanced strategy, aiming at existing equilibrium analysis from domestic and foreign, considering all factors, this paper use a suitable balance-control strategy for battery. Design a kind of battery equalization circuit by the energy transfer with inductance, and built a Semi-physical model of equalization circuit with three lithium iron phosphate battery in saber simulation software, and then get the simulation results and waveforms from the equilibrium charge-discharge simulation. Verify the reasonableness of the circuit configuration, and provide a reference for the physical parameter selection and design.