弱电网下多逆变器并网控制通道间的交互影响分析  

Analysis on Interactive Influences Among Control Loops of Multi Inverters Connected to Weak-Structured Power System

作　　者：唐振东[1] 杨洪耕[1] 袁林[1] 

机构地区：[1]四川大学电气信息学院,四川省成都市610065

出　　处：《电网技术》2016年第11期3524-3531,共8页Power System Technology

摘　　要：弱电网下,长距离的输电线路和并网逆变器数目的增加使得多逆变器并网时的电网阻抗不可忽略。电网等值阻抗的存在将多个逆变器通过公共连接点(point of common coupling,PCC)耦合起来从而引起逆变器控制通道间产生复杂交互影响。建立弱电网下多逆变器并网等效模型,采用基于频率的RGA矩阵与NI指数相结合的方法对逆变器控制通道间的交互作用进行定量分析,在确保并网系统稳定性的前提下,给出了随着并网逆变器台数、控制参数和电网等值阻抗改变时交互影响的变化特性。最后,在Simulink仿真平台中搭建多逆变器并网模型,验证分析结果正确性的同时精确描述了多逆变器并网时随着逆变器并网台数的增加控制交互影响变化的一般规律。Long-distance power transmission and increasing number of grid-connected inverters make power network equivalent impedance for grid-connected multi inverters not ignorable in weak-structured power systems. Existence of power network equivalent impedance couples multiple inverters in PCC, and then causes complex interactive influences among control loops of multi inverters. Equivalent model of multi inverters connected to weak-structured power system was established. Dynamic relative gain array based on frequency was used to quantitatively analyze interactive influences among control loops of multi inverters and give interactive change characteristics for changing grid-connected inverter units, control parameters and power grid equivalent impedance. Finally, grid-connected multi inverters model was built in Simulink platform to verify correctness of analytical results. General rules of changing interactive influences among control loops with increasing number of grid-connected inverters were accurately described.

关 键 词：弱电网 相对增益矩阵 NI指数 控制交互 多并网逆变器 

分 类 号：TM721[电气工程—电力系统及自动化]