基于容量修正的阀控式铅酸蓄电池SOC估计

阀控式铅酸蓄电池(valve regulated lead acid battery,VRLA)广泛应用于储能系统中,准确估算其实时荷电状态(state of charge,SOC),对确保铅酸蓄电池安全供电具有重要意义。铅酸蓄电池的工作环境温度对其容量的影响不可忽视,然而,现有的SOC估算方法常将电池总容量视作固定值,这就导致了估算误差会随着环境温度的变化而积累,严重影响了SOC的估算精度。提出了一种基于容量修正的SOC估计方法,通过研究电池容量随温度的变化规律,引入了温度补偿对电池总容量进行修正。在此基础上,结合扩展卡尔曼滤波(EKF)算法进行不同温度下的SOC实时估计,并对容量修正后的SOC估计值与一般算法SOC估计值进行比较。仿真和实验结果表明,所提出的SOC估算方法能够提高不同环境温度下的铅酸蓄电池SOC估计精度。

State-of-charge estimation of VRLA based on correction of capacity

VRLA batteries were widely used in energy storage systems.It was very important to estimate the SOC of the lead-acid batteries accurately so that the security of electricity supply was ensured.The ambient temperature of VRLA batteries couldn't be ignored,but the existed estimating strategies of SOC treated the capacity as a constant value.These estimation strategies may bring about large errors with the ambient temperature changing.To solve this problem,the temperature compensation coefficient correction with capacity by studying the variation of the capacity according to ambient temperature was introduced.Then the extended Kalman filter (EKF) algorithm was used to estimate the SOC of VRLA at different ambient temperatures,and compared with the general precision of SOC estimated strategies.The simulation and experimental results show that the accuracy of SOC estimation can be improved by this approach under different ambient temperature.