摘要
在直流微网的分层控制结构中,下垂控制作为初级控制的重要组成部分,主要用于实现各微源之间的自主功率分配。重点分析直流微网中下垂控制稳定性及灵敏度的影响因素。通过大信号平均模型导出系统动态调整下垂系数时系统平衡点的存在条件,借助小信号数学模型分析了系统下垂系数、线路参数等变化时系统的特征根轨迹。最后,通过灵敏度分析得出线路电感和恒功率负荷的变化对系统稳定性能影响较大。仿真结果表明,系统参数变化对稳定性的影响与理论分析一致,为直流微网下垂控制设计提供理论依据。
In hierarchical control structure of the DC micro-grid,droop control,as an important part of primary control,is mainly used to achieve autonomous power distribution among micro-sources. This paper mainly analyzed the factors affecting the stability and sensitivity of droop controlled in the DC micro-grid. Based on a large-signal average model,this paper derived the conditions of existence of the system equilibrium point when the droop coefficient was regulated dynamically in the system. With the help of a small-signal mathematical model,it analyzed the trajectory of the characteristic root of the system attributable to changes of the droop coefficient and line parameters of the system. Finally,the sensitivity analysis indicated that changes of line inductance and constant power load could produce significant influence on system stability. Simulation results indicated that the influence of parameter variations of the system upon its stability was consistent with the theoretical analysis,and provided a theoretical basis for the design of droop control of the DC micro-grid.
作者
刘宿城
李中鹏
刘晓东
方炜
Liu Sucheng;Li Zhongpeng;Liu Xiaodong;Fang Wei(Provincial Key Lab of Power Electronics & Motion Control, Anhui University of Technology, Ma’anshan Anhui 243032, China)
出处
《电气自动化》
2019年第1期16-18,50,共4页
Electrical Automation
基金
国家自然科学基金项目(51407003)
安徽省自然科学基金项目(1508085EQE97)
关键词
直流微网
下垂控制
稳定性分析
数学模型
灵敏度分析
根轨迹
DC micro-grid
droop control
stability analysis
mathematical model
sensitivity analysis
root locus
