基于零模增量的多端柔直线路单极接地保护方法
Single-pole grounding protection method for multi-terminal flexible DC transmission line based on zero-mode increment
鄢仁武 1张国和 1李培强1
作者信息
- 1. 福建理工大学 电子电气与物理学院,福建 福州 350118
- 折叠
摘要
柔性直流系统发生的故障通常为单极接地故障,发生故障后保护应在几毫秒内隔离故障线路避免对整个系统产生不利影响,如何实现故障线路快速可靠识别是MTDC直流线路保护中亟待解决的重要问题.首先,分析了模量分解后的线路故障特征,其次,利用线路两端保护安装处零模电流增量的相关性与零模电压增量方向构建保护一体化判据,提出一种基于零模增量的单极接地故障保护方案,该方法可在故障后 1ms内完成故障判别,在 500 Ω过渡电阻下仍能准确辨识,兼顾了速动性与可靠性,最后通过仿真验证本保护方案的可行性与优越性.
Abstract
The fault of the flexible DC system is usually a single-pole grounding fault.After the fault occurs,the protection should isolate the fault line within a few milliseconds to avoid adversely affecting the entire system.How to realize fast and reliable identification of the fault line is an important problem to be solved in MTDC DC line protection.Firstly,the fault characteristics of the line after modulus decomposition are analyzed.Secondly,the correlation of the zero-mode current increment at the protection installation at both ends of the line and the direction of the zero-mode voltage increment are used to construct the integrated protection criterion,and a single-pole grounding fault protection scheme based on zero-mode increment is proposed.This method can complete fault identification within 1 ms after the fault occurs,and can accurately perform identification under the 500 Ω transition resistance,taking into account both speed and reliability.Finally,the feasibility and superiority of the protection scheme are verified by simulation.
关键词
柔性直流输电/单极接地故障/线路保护/模量分解/相关性/一体化判据Key words
flexible DC transmission/single-pole grounding fault/line protection/modulus decomposition/correlation/integrated criterion引用本文复制引用
出版年
2024
NETL
NSTL
万方数据