State-of-charge Balance Control and Safe Region Analysis for Distributed Energy Storage Systems with Constant Power Loads  

作　　者：Yijing Wang Yangzhen Zhang Zhiqiang Zuo Xialin Li 

机构地区：[1]Department of Electrical and Information Engineering,Tianjin University,Tianjin 300384,China

出　　处：《CSEE Journal of Power and Energy Systems》2024年第4期1733-1745,共13页中国电机工程学会电力与能源系统学报（英文）

基　　金：supported by the National Natural Science Foundation of China under Grant 61933014 and Grant 62173243.

摘　　要：This paper presents a fully distributed state-of-charge balance control (DSBC) strategy for a distributed energy storage system (DESS). In this framework, each energy storage unit (ESU) processes the state-of-charge (SoC) information from its neighbors locally and adjusts the virtual impedance of the droop controller in real-time to change the current sharing. It is shown that the SoC balance of all ESUs can be achieved. Due to virtual impedance, voltage deviation of the bus occurs inevitably and increases with load power. Meanwhile, widespread of the constant power load (CPL) in the power system may cause instability. To ensure reliable operation of DESS under the proposed DSBC, the concept of the safe region is put forward. Within the safe region, DESS is stable and voltage deviation is acceptable. The boundary conditions of the safe region are derived from the equivalent model of DESS, in which stability is analyzed in terms of modified Brayton-Moser's criterion. Both simulations and hardware experiments verify the accuracy of the safe region and effectiveness of the proposed DSBC strategy.

关 键 词：Constant power load(CPL) distributed control distributed energy storage system(DESS) safe region state-of-charge(SoC) 

分 类 号：TM73[电气工程—电力系统及自动化]