“锂离子电池—超级电容”混合储能系统的建模与状态估计

Modeling and state estimation of "lithium-ion battery-supercapacitor" hybrid energy storage system

在混合储能系统中,状态估计是进行各储能元件间功率分配和控制策略调整的基础。为减小状态估计误差对后续能量管理的影响,以“锂离子电池-超级电容”混合储能系统为研究对象,进行建模仿真和精确状态估计。首先在辨识基本元件参数后,基于电路的物理结构,在MATLAB/Simulink环境中搭建了混合储能系统仿真模型,用于快速准确的模拟实物实验。然后综合复杂度和估计精度考虑,重新选择以整体形式的理念建立了电池组和超级电容组模型,用于配合“EKF-两点法”进行荷电状态与健康状态的联合估计。最后,经实验验证表明,状态估计误差都在5%以内,即建立的仿真模型能够准确反映元件运行特性且联合状态估计算法精度较高。

In hybrid energy storage systems,state estimation is the basis for power allocation and control strategy adjustment among the storage elements.In order to reduce the impact of state estimation errors on the subsequent energy management,a hybrid energy storage system"li-ion battery-supercapacitor"is used for modeling and simulation and accurate state estimation.Firstly,after identifying the basic component parameters,a simulation model of the hybrid energy storage system is built in MATLAB/Simulink environment based on the physical structure of the circuit for fast and accurate simulation of the physical experiment.Then,considering the complexity and the accuracy of estimation,the battery pack and the supercapacitor pack are modeled in a holistic form,and the joint estimation of charge state and health state is carried out with the"EKF-two-point method".Finally,the experimental verification shows that the errors of the state estimation are within 5%,i.e.,the simulation model established in this paper can accurately reflect the operating characteristics of the components and the accuracy of the joint state estimation algorithm is high.