风-光储能系统锂离子电池SOC校准优化方法

Optimization Method of SOC Calibration for Lithium-Ion Battery in Wind-Solar Energy Storage System

使用安时积分法估算电池荷电状态(SOC)在工业上已有广泛应用,但对于风光互补发电系统来说,使用开路电压(OCV)校准安时积分法的累积误差不切实际,因为OCV法需要电池静置数小时。针对此问题,提出一种新的校准方法,该方法与OCV法类似,但校准条件只需要电池电流恒定或小范围波动维持4 min,更适用于校准风-光储能系统中使用安时积分法存在的误差累积问题。使用4串6并的软包钴酸锂电池进行试验测试,在3.9、3.6、3.2 V三个不同电压平台中,所提出的策略与实际OCV误差均小于10 mV,换算成SOC均小于1%,证明了本文所提出策略的可行性。

The ampere-hour integral method in industry to estimate the state of charge(SOC) of battery. However, it is impractical to use open circuit voltage(OCV) to calibrate the cumulative error of ampere-hour integral method for wind-solar energy storage systems. Because the OCV method requires the battery to be stationary for several hours. To address this problem, a new calibration method is proposed, which is similar to the OCV method, but its calibration conditions only require the current of battery constant or maintain 4 min fluctuation in a small range, which is more suitable for calibrating the error accumulation problem in wind-solar energy storage systems using the ampere-hour integral method. 4S6P soft pack lithium-ion batteries is used for experimental testings in 3.9 V, 3.6 V and 3.2 V about three different voltage platforms, the proposed strategy and the actual OCV error were less than 10 mV, and the conversion to SOC is less than 1%, which prove the feasibility of the proposed strategy.