基于数字能量交换系统的动力电池无损梯次利用储能技术研究

Energy and Economic Efficiency of Li-ion Battery Packs Re-used in Stationary Energy Storage Application

退役动力电池在有效容量、健康状况、循环寿命等方面具有显著差异性,单体级拆分、固定重组的梯次利用技术方案难以提高梯次利用储能系统的可靠性、安全性和能量效率。该文基于可重构电池网络技术,提出数字无损动力电池梯次利用技术的数字能量交换系统。首先,分析退役动力电池梯次利用动力电池系统的可行性,提出电池包或模组级重构的梯次利用储能系统方案。接着,阐述数字能量交换系统的技术基础并提出其原理框架,建立可重构电池网络的容量变化模型,总结出数字能量交换系统的优化问题。根据数学模型推导基于可重构电池网络的智能梯次利用动力电池管控策略,实现梯次利用电池储能系统能量信息化、数字化管控。然后,根据数字能量交换系统特征,推导基于可重构电池网络的卡尔曼滤波与开路电压–荷电状态映射相结合的在线电池荷电状态估算算法。最后,基于梯次利用储能项目示范工程,使用信息熵与物理系统熵的概念解释数字储能系统对电池进行一致性的管控,验证了系统的效能。

Retired vehicle power batteries have significant differences in terms of available capacity,health status,and cycle life.Based on the reconfigurable battery network technology,this paper proposed a digital energy exchange system based on the digital lossless power battery cascade utilization technology.Firstly,the feasibility of the cascade utilization power battery system of retired power batteries was analyzed,and the cascade utilization energy storage system scheme of battery pack or module level reconstruction was proposed.Then,the technical basis of the digital energy exchange system was expounded and its principle framework was proposed,the capacity change model of the reconfigurable battery network was established,and the optimization problem of the digital energy exchange system was summarized.According to the mathematical model,the intelligent cascade utilization power battery management and control strategy based on the reconfigurable battery network was deduced,and the energy information and digital management and control of the cascade utilization battery energy storage system were realized.Then,according to the characteristics of digital energy exchange system,an online battery state-of-charge estimation algorithm based on Kalman filter of reconfigurable battery network combined with open-circuit voltage-state-of-charge mapping was deduced.Finally,based on the demonstration project of cascade utilization of energy storage project,the concept of information entropy and physical system entropy was used to explain the consistent management and control of batteries by the digital energy storage system,and the efficiency of the system was verified.