摘要
针对独立运行的直流微电网,提出了一种考虑不匹配线路阻抗和储能容量的分布式储能系统分级控制策略。通过负荷平衡级控制动态地微调虚拟阻抗,消除不匹配线路阻抗对电流负荷分配精度的影响;进而通过荷电状态(SOC)平衡级控制,各个储能单元根据其容量和SOC动态地调节电流负荷,使得SOC误差以e指数曲线下降,最终实现储能单元在充放电过程中SOC均衡。所提方法采用动态一致性算法,可实现各分布式储能单元的信息共享,提高了系统的可靠性与灵活性。通过小信号稳定性分析,讨论关键参数对系统稳定的影响。基于RTDS设计了3种实验方案,结果验证了所提方法能够使得电流负荷按储能容量合理分配,提高了系统的扩展性和通用性。
A hierarchical control strategy of distributed energy storage system is proposed for the independent DC microgrid,which considers the mismatched line impedance and energy storage capacity. The virtual impedance is adjusted dynamically by the load balance control to eliminate the influence of mismatched line impedance on the current load distribution accuracy. Then,through the SOC(State-Of-Charge) balance control,the current load is adjusted dynamically according to the capacity and SOC of each energy storage unit,so that the SOC error decreases by e-exponential curve,and finally the SOC balance of energy storage unit in the charging and discharging process is realized. The proposed method is solved by the dynamic consistency algorithm to realize information sharing among distributed energy storage units,which improves the reliability and flexibility of the system. The influence of key parameters on the system stability is discussed through small-signal stability analysis. Three kinds of experimental schemes are designed based on RTDS and experimental results verify that the proposed method can reasonably allocate current load according to energy storage capacity and improve the scalability and versatility of the system.
作者
米阳
蔡杭谊
袁明瀚
陈鑫
符杨
王成山
MI Yang;CAI Hangyi;YUAN Minghan;CHEN Xin;FU Yang;WANG Chengshan(College of Electric Power Engineering,Shanghai University of Electric Power,Shanghai 200090,China;School of Mechatronic Engineering and Automation,Shanghai University,Shanghai 200072,China;Key Laboratory of Smart Grid of Ministry of Education,Tianjin University,Tianjin 300072,China)
出处
《电力自动化设备》
EI
CSCD
北大核心
2019年第10期17-23,共7页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(61873159)
上海市科委项目(18020500700)
上海绿色能源并网工程技术研究中心项目(13DZ2251900)~~
关键词
直流微电网
下垂控制
分布式储能系统
虚拟阻抗
荷电状态
小信号稳定性分析
DC microgrid
droop control
distributed energy storage system
virtual impedance
state-of-charge
small-signal stability analysis
