Energy Storage Science and Technology ›› 2021, Vol. 10 ›› Issue (6): 2283-2292.doi: 10.19799/j.cnki.2095-4239.2021.0095

• Energy Storage System and Engineering • Previous Articles     Next Articles

Research on collaborative control strategy for simultaneous decommissioning based on multi-branch PCS topology of ESS using second-life EV batteries

Yongqiang ZHENG1(), Yue WU2, Panpan ZHANG1, Bo LEI2, Yaodong ZHENG3   

  1. 1.Zhuhai Watt Electrical Equipment Co. , Ltd. , Zhuhai 519080, Guangdong, China
    2.Electric Power Research Institute, China Southern Power Grid, Guangzhou 510080, Guangdong, China
    3.China Southern Power Grid, Guangzhou 510663, Guangdong, China
  • Received:2021-03-10 Revised:2021-03-27 Online:2021-11-05 Published:2021-11-03
  • Contact: Yongqiang ZHENG E-mail:watt_ky@163.com

Abstract:

A coordinated control strategy based on a multi-branch power conversion system (PCS) topology was designed to address the problem of simultaneous decommissioning among different battery modules in an energy storage system (ESS) using second-life electric vehicle (EV) batteries. Considering the power demand in different periods and the imbalance degree of battery state of health (SOH) in ESS, the priority output mode to utilize batteries with better health status or common output mode of the entire battery group was selected. Based on the distribution of battery state of charge (SOC), a control strategy employing real-time variable current as a positive feedback regulation value was used to achieve coordinated control and output balancing within the ESS's battery cluster. After multiple charges and discharges, the SOH of each battery module in one cluster tends to be asymptotically consistent, thus achieving the goal of decommissioning different batteries simultaneously. Finally, the simulation analysis confirmed that the strategy could simultaneously decommission each retired power battery pack in the energy storage system.

Key words: second-life batteries, simultaneous decommissioning, state of health, state of charge, multi-branch collaborative control

CLC Number: