基于4维Map图的镍氢电池SOC估计方法

针对现有镍氢电池荷电状态(SOC)估计方法因精确度太低或者对数据、模型参数要求太高而难以实用的问题,提出一种基于4维Map图的电池SOC估计方法.通过大量实验数据,建立镍氢电池SOC与温度、电流和端电压之间的基本Map图,发现在其工作区间20％≤YSOC≤80％内,不同电流、温度条件下的相邻充放电特性曲线基本相互平行.以SOC与端电压之间的关系为基础,分别在电流和温度方向上采用曲线平移的方式插值得到SOC与电流、温度、电压之间的4维Map图模型.利用试验数据进行SOC估计试验,试验结果表明,利用4维Map图模型的SOC估计误差在3％以内,基于4维Map图的镍氢电池SOC估计方法能满足电动汽车电池SOC估计在精确度和易实现性上的要求.

Four-dimensional Map based Ni-MH battery' s SOC estimation method

A battery’s state of charge(SOC) estimation method based on the four-dimensional Map was proposed to solve the problems of current SOC estimation methods which accuracy was too low or too sensitive to data or model parameters that can not be used in practice.A Map which reflects the relation among the Nickel-Metal Hydride(Ni-MH) battery’s temperature,current,voltage and its SOC was established with a large number of experimental data.The approach was inspired by the finding that the adjacent charge-discharge character curves with different current,and temperature conditions are in parallel with each other within the work-interval(20%≤YSOC≤80%) of the battery.Therefore,the four-dimensional Map model of SOC,with current,temperature and voltage as its parameters,was established by interpolating in the current and temperature directions through moving the curves which is based on the relation between SOC and terminal voltage.Some experiments were conducted to verify the Map model and the result indicate that the SOC estimation error of the model is less than 3%.The SOC estimation method based on the four-dimensional Map can meet the requirements of industrial production both in accuracy and ensy realization.