储能科学与技术 ›› 2022, Vol. 11 ›› Issue (12): 3872-3882.doi: 10.19799/j.cnki.2095-4239.2022.0418

• 储能系统与工程 • 上一篇    下一篇

锂离子电池储能系统多时间尺度均衡方法

丁凯(), 钱一民, 陈乔, 郑剑, 王易   

  1. 国网湖北省电力有限公司电力科学研究院,湖北 武汉 430077
  • 收稿日期:2022-07-27 修回日期:2022-07-30 出版日期:2022-12-05 发布日期:2022-12-29
  • 通讯作者: 丁凯 E-mail:douyan28859@163.com
  • 作者简介:丁凯(1974—),男,博士,高级工程师,研究方向为电能质量与优质供电,E-mail:douyan28859@163.com
  • 基金资助:
    国网湖北电力公司科技项目(52153221000N)

Multitimescale equalization method for lithium-ion battery energy storage systems

Kai DING(), Yimin QIAN, Qiao CHEN, Jian ZHENG, Yi WANG   

  1. Electric Power Research Institute of State Grid Hubei Electric Power Co. , Ltd. , Wuhan 430077, Hubei, China
  • Received:2022-07-27 Revised:2022-07-30 Online:2022-12-05 Published:2022-12-29
  • Contact: Kai DING E-mail:douyan28859@163.com

摘要:

锂离子电池可作为后备电源为电力系统的一次设备、二次设备及通信管理等提供不同等级的交直流电,保证核心设备紧急时刻仍然能够正常工作。先串后并的并联型储能系统不仅因并联模组的互为备用具有更高的可靠性,也能够避免传统串联型后备电源的木桶效应问题。然而,并联型方案会因模组之间的不一致,使得各模组寿命呈现差异性;串联电池组组内电压分布差异,也会导致电池单体过充或者过放。为此提出了一种针对并联型锂离子电池储能系统的多时间尺度均衡方法。首先,对电池模组组内单体以荷电状态(state of charge,SOC)为指标进行旁路均衡,使电池组在单次充放电循环的短时间尺度达到组内均衡;然后,通过并联电池模组组间的寿命均衡,使系统在寿命衰减的长时间尺度达到平衡。所提均衡方法能够提高并联型储能系统使用过程中模组间的一致性,增强并联模组互为备用的可靠性,降低运维成本,提高锂离子电池的使用效率。为了验证该均衡方法,在电池加速老化实验的基础上,搭建仿真模型验证了所提方法在不同条件下的有效性。

关键词: 储能系统, 锂离子电池, SOC均衡, 寿命均衡

Abstract:

Lithium-ion batteries can serve as backup power supplies to provide different alternate and direct current power levels for the primary and secondary equipment and communication management of the power system to ensure that the core equipment continues to function normally in emergencies. The parallel energy storage system has higher reliability due to the parallel module backup and can also avoid the barrel effect of traditional series backup power supply. However, the parallel scheme can cause differences in module life due to the inconsistencies between modules. Additionally, differences in voltage distribution within the series-connected batteries can lead to overcharging or over-discharging of the battery cells. Therefore, we propose a multitimescale equalization method for parallel lithium-ion battery storage systems. First, bypass equalization is performed on the single cell within the battery module group with the state of charge as the index to achieve intragroup equalization in the short-time scale of a single charge/discharge cycle. Subsequently, the system is balanced in the long-time scale of life decay through the life equalization between parallel battery module groups. Interestingly, the proposed equalization method can improve the consistency between modules when using a parallel energy storage system, enhance the reliability of parallel modules for mutual backup, reduce the operation and maintenance cost, and improve the efficiency of Li-ion battery use. Furthermore, a simulation model is built to verify the effectiveness of the proposed method under different conditions based on accelerated battery aging experiments to verify the equalization method.

Key words: energy storage systems, Li-ion batteries, SOC equalization, lifetime equalization

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