基于改进下垂控制的并网级联型储能系统SOC均衡策略  

SOC balancing strategy of a grid-connected cascaded-type energy storage system based on advanced droop control

作　　者：户艳琴 周仁友 黄天翔 张延 宁涛 于晶荣[2] HU Yanqin;ZHOU Renyou;HUANG Tianxiang;ZHANG Yan;NING Tao;YU Jingrong(State Grid Jiangxi Integrated Energy Service Co.,Ltd.,Nanchang 330096,China;College of Automation,Central South University,Changsha 410083,China)

机构地区：[1]国网江西综合能源服务有限公司,江西南昌330096 [2]中南大学自动化学院,湖南长沙410083

出　　处：《电力系统保护与控制》2021年第22期120-129,共10页Power System Protection and Control

基　　金：湖南省自然科学基金项目资助(2017JJ2348);国网江西省电力有限公司科技项目“开展台区综合能效管理和提升的应用技术研究”(521855190001)。

摘　　要：针对并网级联型电池储能系统的电池荷电状态(State of Charge,SOC)不均衡问题,提出了一种基于改进下垂控制的电池组SOC均衡策略。该策略在传统下垂控制基础上,通过考虑各电池组SOC实时估计信息,在不影响正常功率输出并保持与电网同步的前提下,引入分配修正项来实时优化分配各级联模块的有功功率和电压幅值参考,实现各级联模块的SOC均衡。通过调整分配修正系数,调节各级联模块输出功率差异,从而控制电池组的SOC均衡速度。采用奇异理论分析了该控制策略的稳定性,给出了控制参数的设计依据。不同工况下级联型储能系统的仿真结果,验证了所提控制策略及其理论分析的正确性和有效性。There are imbalance problems in the State of Charge(SOC)of batteries in grid-connected cascaded-type battery energy storage systems.Thus an improved droop control considering SOC balancing strategy is proposed.Based on traditional droop control,this method introduces a distribution correction term by considering SOC real-time estimation information of each battery pack.Then the reference active power and reference voltage amplitude can be reasonably distributed according to the SOC information,and the SOC balancing of each module is achieved without affecting the normal power output as well as keeping synchronization with the grid.In this way,the SOC balancing speed can be adjusted by changing the correction coefficient.In addition,stability analysis of the system based on singular perturbation theory is carried out,and the design basis for control parameters is given.The simulation results under different conditions verify the correctness and validity of the proposed control strategy and the theoretical analysis.

关 键 词：并网级联型储能系统 P−ω下垂控制 电网同步 有功功率平衡 SOC均衡 

分 类 号：TM91[电气工程—电力电子与电力传动]