Research On Lithium Iron Phosphate Battery Pack Equalization Control Strategy

In recent years, electric vehicle power sources are highly polluting to less polluting lead-acid batteries, lithium iron phosphate battery, thereby encouraging the use of electric vehicles policy is also increasing. As one of the core part of the battery cell vehicles, intelligent management of its significance. Output power of electric vehicles is about one hundred kilowatts, are generally required battery voltage of several hundred volts, but due process and safety issues of lithium iron phosphate, single battery capacity can not be too large, so as to meet the power requirements, it is necessary to a number of series and parallel lithium iron phosphate monomer after use. Although the same batch of lithium iron phosphate batteries, also due to manufacturing variances, since different discharge rate, the use of aging causes the monomers remaining battery power is inconsistent. Inconsistency of the battery pack with a serious impact on the efficiency of the battery life, so the battery pack charge balance is essential.In this paper, the consistency of the battery pack of the above analysis, combined with previous studies had balanced program proposed equalization scheme to meet the battery pack during charging and discharging, the energy can be real-time monitoring the health status of the battery and the battery between balancing. TMS320F2812 as a management system control module, single battery voltage acquisition completed by the bq76PL536A-Q1 battery monitor, single battery temperature acquisition completed by the DS18B20, battery charge and discharge function module current acquisition is completed by the Hall sensors. Balanced battery pack using the energy dissipative non-equilibrium mode, using TI’s TPS55010 as equalization module, and the battery state of charge SOC (State Of Charge) based on the design of a new equalization algorithm, a balanced response faster and more accurate higher efficiency equilibrium. To complete the study of this topic for a balanced strategy proposed to build an experimental platform and record the relevant experimental results and simulation data, experiments show that the proposed intelligent management system can view real-time single cell voltage, temperature, battery pack and the remaining battery charge and discharge current, the equalization module design effectively solve the consistency problem of the battery pack.