平行双回线路纵联零序方向误动原因分析及负序功率方向研究  

Analysis of the reason of pilot zero sequence directional protection mal-function and study of negative sequence directional element on parallel double-circuit lines

作　　者：蒋苏静[1] 毕天姝[1] 徐振宇[2] 房金彦[1] 

机构地区：[1]华北电力大学,北京102206 [2]北京四方继保自动化股份有限公司,北京100085

出　　处：《电力系统保护与控制》2009年第24期21-26,共6页Power System Protection and Control

摘　　要：平行线路若在强磁弱电联系方式下运行,一回线路的接地故障可能会引起另一回线路零序功率方向保护误动。分析了强磁弱电情况下零序功率方向保护误动的原因以及双回线路各种连接方式对方向元件产生的影响。针对零序方向保护容易误动的情况,提出使用负序功率方向元件作为纵联方向保护的方向元件并对采用负序补偿电压代替负序电压做了分析。PSCAD的大量仿真表明,负序功率方向元件可以正确反应正常运行、故障线路的区内、区外故障,同时在非故障线路中不会误动。Earthed fault which occurs on one of two parallel double-circuit lines under the strong-magnetic and weak-current operation condition may result in mal-function of the pilot zero sequence directional protection of the non-fault line. Both the reason of mal-function and the types of connection which is easy to lead to mal-function are analyzed in the paper. Using the negative sequence directional element as directional element of the pilot protection can avoid the problem of easy mal-function of the zero sequence one. Compensatory negative sequence voltage which replaces the negative sequence voltage is also analyzed in the paper. PSCAD software simulations show that the negative sequence directional element can indicate the normal operation, in-zone fault and out-zone fault of fault line, in the meanwhile the one of non-fault line will not mal-operate.

关 键 词：平行双回线路 零序功率方向元件 负序功率方向元件 纵联方向保护 强磁弱电 

分 类 号：TM773[电气工程—电力系统及自动化]