基于分压器原理的孤岛检测技术在微电网中的应用  

Islanding Detection Method Based on Voltage Divider for Microgrid

作　　者：李军[1] 黄学良[1] 陈小虎[2] 徐文[1] 谢淼[1] 

机构地区：[1]东南大学,江苏省南京市210096 [2]南京工程学院,江苏省南京市211167

出　　处：《中国电机工程学报》2010年第34期15-21,共7页Proceedings of the CSEE

基　　金：江苏省"六大人才高峰"基金项目(1116000088)~~

摘　　要：应用于微电网的孤岛检测技术在具有分布式发电系统孤岛检测所必需的快速性、准确性的同时,还要保证微电网状态转换过程的平稳性。为此,结合微电网与主网系统并网前后联络线处等值系统阻抗随之变化的特点,利用分压器原理,将联络线处系统等值阻抗的变化映射为联络线电压幅值的变化,无需精确求解阻抗变化数值,即可准确判断出孤岛状态的发生;同时,该方法可以有效避免对微电网孤岛运行稳定性产生不利影响。在此基础上,从工程实现角度出发,设计出2种简单易行的孤岛检测电路,并利用Matlab/Simulink分别对其进行建模仿真分析,验证了该方法用于微电网孤岛检测的快速性和有效性,分析比较了2种检测电路的优缺点,给出了工程应用方面的建议。A desired islanding detection method applied to a microgrid can detect islanding within an acceptable time duration as correctly as that used in a distributed generation system; besides, it does not interfere a smooth transition from grid-connected mode to islanded mode. On this basis, an islanding detection method, which considered the characteristics of system equivalent impedance varying before and after the connection of the microgrid and the main grid, was presented. With the help of a voltage divider, the transformation from equivalent impedance variation to voltage variation near the point of common coupling （PCC） was mapped, and then the islanding status was correctly identified without complicated computation of impedance variation. The method is able to avoid negative impact on the operation stability of the microgrid. Based on these principles, two simple islanding detection circuits were designed for engineering application. Through the Matlab/Simulink simulation, the rapidity and effectivity of these principles were demonstrated. At last, some suggestions were provided for engineering application after analyzing and comparing the merits and demerits of the two circuits.

关 键 词：微电网 主网 分布式发电 孤岛检测 阻抗变化 分压器原理 映射 工程应用 

分 类 号：TM71[电气工程—电力系统及自动化]