引入功率微分项的并网下垂控制逆变器小信号建模与分析  

Small-signal modeling with power differential term for droop control inverter and analysis

作　　者：陈昕[1] 张昌华[1] 黄琦[1] 

机构地区：[1]电子科技大学能源科学与工程学院,四川成都611731

出　　处：《电力自动化设备》2017年第2期151-156,163,共7页Electric Power Automation Equipment

基　　金：留学回国人员科研启动基金资助项目;中央高校基本科研业务费资助项目(ZYGX2015J104)~~

摘　　要：针对经典的电压-频率下垂控制系统受扰易产生振荡的问题,提出了加入功率微分项的下垂控制方法。建立了经典下垂控制与所提加功率微分项的下垂控制的并网逆变器完整的小信号模型。分析了下垂系数与功率微分系数对系统特征根分布的影响,得到了加入功率微分项后系统低频域特征根阻尼比增加、可有效抑制扰动带来的振荡的结论;分析了各参数变化对系统稳定性的影响,为系统参数设计与性能分析提供了理论依据。最后通过MATLAB/Simulink建立模型,在同样初始状态下系统取不同参数以及不同控制策略时,系统受扰的响应与理论分析一致,验证了建模与理论分析的正确性。Aiming at the easily-induced oscillation of conventional voltage-frequency droop control system,a droop control with additional power differential term is proposed. A complete small-signal model of gridconnected inverter is developed for the conventional droop control and an improved one with additional power differential term for the proposed droop control. The impacts of droop coefficient and power differential coefficient on the distribution of system characteristic roots are studied and it is concluded that,with the additional power differential term,the damping ratio of low-frequency characteristic root is increased and the disturbance-induced oscillation is effectively suppressed. The influences of different parameters on the system stability are analyzed,which provides a theoretical basis for the system parameter design and system performance analysis. The models are built with MATLAB / Simulink and the simulative system response to disturbance is identical with that of theoretical analysis for different system parameters and different control strategies in the same initial conditions,which verifies the correctness of modeling and theoretical analysis.

关 键 词：微电网 逆变器 下垂控制 小信号稳定性 功率微分项 

分 类 号：TM464[电气工程—电器]