分布式逆变器孤岛保护检测新方法的研究

Research on a Novel Method for Distributed Inverter Island Protection Detection

孤岛检测最核心的功能是保障并网系统安全稳定运行,本文介绍了针对非计划孤岛检测的传统方法和原理,分析了当前主要用于孤岛检测的主动孤岛和被动孤岛技术,并提出了一种基于频率检测和主动无功注入匹配的混合式孤岛检测新方法。该方法借由识别并网点的频率变化执行无功注入,形成正反馈机制,有效判断孤岛运行情况的发生。在平台实验过程中,成功达到了各种复杂工况下的检测要求,并克服了多台逆变器同时检测不能同时触发的问题,验证了该方法的显著效果。

The core function of island detection is to ensure the safe and stable operation of grid connected system,this paper introduces the traditional methods and principles of unplanned island detection,analyzes the current active island and passive island technologies mainly used for island detection,and proposes a new hybrid island detection method based on frequency detection and active reactive power injection matching.This method identifies the frequency change of the parallel node,performs reactive power injection,forms a positive feedback mechanism,and effectively judges the occurrence of island operation.In the process of platform experiment,the detection requirements under various complex working conditions are successfully met,and the problem that multiple inverters can detect at the same time but can not trigger at the same time is overcome.The remarkable effect of this method is verified.