基于DC-DC开关电源的梯次电池并联特性研究

Analysison Parallel Characteristics of New DC-DC Switching Power Supply Power Second-use Battery

为提高动力梯次电池的输出性能,本文基于直流-直流变换(direct current-direct current,DC-DC)开关电源,对梯次电池并联特性进行研究。以某小型电动观光高尔夫汽车退役的磷酸铁锂电池为研究对象,设计了一种DC-DC开关电源技术,实现对梯次电池的充放电。同时,对电池内阻、剩余容量及初始SOC不一致的情况进行研究,验证了梯次磷酸铁锂电池在内阻差别较小的情况下可进行小电流放电,对电池的总容量影响较小。同时,使用DCDC开关电源对电池进行充放电实验。实验结果表明,当SOC较低时,梯次电池的极化内阻明显变大,电池不一致性显著增加,利用梯次电池时,应选择20%~80%的SOC。该研究为梯次电池的循环利用提供了理论基础。

The utilization of power cascade battery is the key to the development of electric vehicle.In order to improve the output performance of the power cascade battery,the cascade battery needs to be re-screened before it can be used in groups.Taking the retired lithium iron phosphate battery of a small electric sightseeing golf car as the research object,a new DC-DC switching power technology is proposed,which can realize the charging and discharging of the battery.The system can be used to study the parallel characteristics of battery cells in different states.Results show that in the use of new type DC-DC switching power supply to charge and discharge of battery,the SOC is lower,arrangement in the polarization of the battery internal resistance significantly larger,battery inconsistency increased significantly,should choose 20%~80%SOC when using pilot battery.The pilot battery recycling provides a theoretical support.