中国电力 ›› 2016, Vol. 49 ›› Issue (5): 59-62.DOI: 10.11930/j.issn.1004-9649.2016.05.059.04

• 安全专栏 • 上一篇    下一篇

互感引起的零序方向保护误动分析与对策

陈水耀12,黄少锋1,杨松伟2   

  1. 1.华北电力大学电气与电子工程学院,北京102206;
    2.国网浙江省电力公司检修分公司,浙江杭州311232
  • 收稿日期:2015-10-10 出版日期:2016-05-16 发布日期:2016-05-16
  • 作者简介:陈水耀(1976—),男,浙江衢州人,博士研究生,高级工程师,从事继电保护故障分析和状态检测技术研究。E-mail: chen-shuiyao@sgcc.com.cn

Analysis and Countermeasures on a Malfunction of Zero-Sequence Directional Protection Due to Mutual Inductance

CHEN Shuiyao1, 2, HUANG Shaofeng1, YANG Songwei2   

  1. 1. School of Electrical and Electronic Engineering, North China Electric Power University, Beijing 102206, China;
    2. State Grid Zhejiang Electric Power Corporation Maintenance Branch, Hangzhou 311232, China
  • Received:2015-10-10 Online:2016-05-16 Published:2016-05-16

摘要: 某220 kV线路高频零序方向保护在区外故障时误动,保护动作前的电压波形存在明显畸变。通过对电压波形进行谐波分析,发现电容式电压互感器(CVT)暂态特性持续时间比较短,一般在5~10 ms,而零序方向保护动作出口在20 ms以后,从而排除了CVT暂态特性不良引起零序方向保护误动的可能性。同时根据线路两侧零序电压、零序电流及零序阻抗,计算出线路上存在感应电压,从而确认相邻线路互感是导致零序方向保护误判的原因,并有针对性地提出负序电流开放零序方向保护的改进措施。

关键词: 零序方向保护, 暂态特性, CVT, 互感

Abstract: A high frequency zero-sequence directional protection of a 220 kV line took false action with obvious distortion on voltage waveform. Through harmonic analysis of voltage waveform, it is found that CVT transient characteristics lasted shortly around 5~10 ms, while zero-sequence directional protection acted 20 ms later. The possibility of malfunction caused by transient characteristics of CVT is excluded. Based on zero-sequence voltage, current and sequence on both sides of protection, the induced voltage is calculated. It is inferred that mutual inductance is the cause of malfunction of zero-sequence directional protection. A new zero-sequence directional protection scheme with negative sequence current opening identification is proposed.

Key words: zero-sequenced directional protection, transient characteristics, CVT, mutual inductance

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