基于频谱比较的直流线路差动保护闭锁判据  

Criterion of HVDC line differential protection blocking based on spectrum comparison

作　　者：李爱民[1] 蔡泽祥[2] 孙奇珍 徐敏 

机构地区：[1]广东电网公司,广东广州510640 [2]华南理工大学电力学院,广东广州510640 [3]广州供电局有限公司,广东广州510600 [4]南方电网科学研究院,广东广州510640

出　　处：《电力自动化设备》2015年第4期115-120,共6页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51077055)~~

摘　　要：为解决目前直流线路差动保护动作时间过长的问题,提出了一种基于频谱比较的直流线路差动保护闭锁判据。分析了差动电流的频谱特征,由分析可知区内故障时差动电流含有较多直流分量,区外故障时差动电流含有较多50 Hz和100 Hz分量,根据这一区别设计了闭锁判据。该判据能够有效识别区内、区外故障,且具有可靠性高、对采样频率要求较低等优点。基于某实际直流系统建立了EMTDC仿真模型。仿真结果表明,该判据能够在区外故障时闭锁差动保护,提高了保护的可靠性。Aiming at the long operation time of HVDC line differential protection,a blocking criterion based on spectrum comparison is proposed. The spectrum characteristics of differential current are analyzed and the analytical results show that,it contains more DC component during the in-zone fault while contains more 50 Hz and 100 Hz components during the out-zone fault,according to which,a blocking criterion is designed. With high reliability and low sampling frequency,it identifies the in-zone and out-zone faults efficiently. A simulation model is built with EMTDC based on an actual HVDC system and the simulative results show that,the differential protection is blocked during the out-zone fault according to the proposed criterion,improving the protection reliability.

关 键 词：高压直流输电 继电保护 差动保护 闭锁 频谱分析 可靠性 仿真 故障分析 

分 类 号：TM721.1[电气工程—电力系统及自动化]