电动汽车电池测试系统建模与仿真

Modeling and simulation of battery in electric vehicle battery test system

针对电动汽车运行过程中产生的谐波会造成电池放电不均匀及导致电池使用寿命减短的问题,为了快速地测试不同电感电容对直流母线谐波的抑制效果,在Simulink下搭建了以电池模型为核心的电池测试系统模型。通过对现有3种常用电池等效电路模型的对比和二阶RC模型的分析,详细描述了电池二阶RC模型中各个部分的作用。采用电池实际放电时采集到的数据,通过最小二乘法对电池开路电压与SOC之间非线性关系进行了曲线拟合,同时对等效电路中的电阻电容参数进行了辨识;介绍了矢量控制算法的原理并采用该控制算法对电机驱动系统进行了建模;最后,建立了整个系统的模型,并设计了两个实验进行了验证。实验结果表明,从所建立的电池测试系统模型得到的数据与实际系统得到的数据相似,该模型可以用来仿真电动汽车运行实际电路。

Aiming at the problems of unbalanced battery discharge and battery life shortened caused by the harmonic generated when electric vehicle is running, in order to test the harmonic of the DC current with different inductors and capacitors quickly, a test system model based on battery model was established in Simulink. Three kinds of popular equivalent circuit model of battery were introduced and compared, the second-order RC model was analyzed. The effect of each part of the second-order RC model based on test data was described, and the curve fitting of the nonlinear relationship between OCV and SOC by the method of least squares was presented in detail. The RC parameters in the equivalent circuit were identified. Vector control algorithm was introduced, which was used in the modeling of motor drive system. At last, the model of the whole system was established, and two tests were designed. The results indicate that the data obtained by the model is quite near to the real system, so it can be used to simulate the resistance and inductance value of real circuit.