基于锂电池精确荷电状态估计的主动式均衡方案研究

The accurate State of Charge (SOC) estimation of the battery is the premise of the active equalization. The equalization effect of the existing technology is limited by the estimation accuracy. The equalization efficiency and speed are low. The objective of this project is to improve the SOC accuracy of the power lithium battery and achieve the reliable equalization. The method combining the theoretical analysis and experimental verification is applied. The active equalization scheme based on the accurate SOC estimation of the lithium battery is studied. Also the SOC can be corrected by the equalization scheme. The main contents are: The battery model is established based on the physical equivalent circuit and chemical electrode reaction. The influence of environmental factors is under considered. The stability and anti disturbance performance of the algorithm are analyzed. On the basis of accurate SOC estimation, the active equalization scheme of the battery pack is discussed. The non-ideal conditions are taken into consideration and the further correction of the SOC can be realized. The implementation of these technologies will help to improve the battery life and energy utilization. The energy loss in the balancing process can be reduced. The equalization speed and reliability can be improved. It is expected to provide new ideals for the modeling and estimation of the non-liner system and the power electronic topologies.

针对目前动力电池组主动式均衡效果受到荷电状态(State of Charge，SOC)估计精度的制约、且均衡效率和速度较低的问题，本项目将以提高锂电池单体SOC估计的精确度、实现可靠均衡为目标，采用理论分析与实验验证相结合的方法，对基于锂电池精确荷电状态估计的主动式均衡方案进行研究，并通过均衡方案对SOC进行修正。主要研究内容有：考虑环境因素的影响，分别从物理等效电路和化学电极反应两种角度对锂电池进行建模；考虑理想条件下均衡的影响，通过精确的电池模型进行基于统一闭环滤波的SOC估计，并对算法稳定性和抗扰动性能进行分析；研究基于SOC估计的电池组的主动均衡方案，并考虑均衡过程中非理想情况的影响，进一步对SOC进行修正。这些技术的实现将有助于提高动力电池的寿命和电能利用率、减小均衡过程中的能量损耗、提高均衡的速度和可靠性，并有望对非线性建模与估计和电力电子拓扑技术方面的研究提供新思路。

目前动力电池组主动式均衡方案的均衡效率和速度较低，且均衡效果受到荷电状态(State of Charge，SOC)估计精度的制约，本项目以提高锂电池单体SOC估计的精确度、实现可靠均衡为目标，采用理论分析与实验验证相结合的方法，对基于锂电池精确荷电状态估计的主动式均衡方案进行了研究，并通过均衡方案对SOC进行修正。主要研究的内容有:考虑环境因素的影响，分别从物理等效电路和化学电极反应两种方式对锂电池进行建模;考虑理想条件下均衡的影响，通过精确的电池模型利用基于统一闭环滤波的的方法对SOC进行估计，并对算法稳定性和抗扰动性能进行了分析; 考虑了均衡过程中非理想情况的影响，研究并设计了基于SOC估计的电池组的主动均衡方案与相应的控制策略， 由此进一步对SOC进行修正，通过实际测量最终SOC的估算误差低于3%。这些技术的实现将有助于提高动力电池的寿命和电能利用率、减小均衡过程中的能量损耗、提高均衡的速度和可靠性，并有望对非线性建模与估计和电力电子拓扑技术方面的研究提供新思路。