PT中性线断线的研究  

Research on PT neutral line failure

作　　者：刘东超[1] 李铁仲[2] 张哲[1] 沈军[1] 赵青春[1] 刘革明[1] 

机构地区：[1]南京南瑞继保电气有限公司,江苏南京211102 [2]北京市电力公司调度通信中心,北京100031

出　　处：《电力系统保护与控制》2010年第5期73-76,81,共5页Power System Protection and Control

摘　　要：对PT中性线断线产生的三次谐波电压及基波零序电压进行了理论分析和实验验证,并提出了实用判据。简述了对PT中性线断线研究的现状,从基本的磁滞回线入手,根据励磁电流、磁通、磁势之间的关系,对PT中性线断线时的三次谐波产生的机理进行了理论分析,对由不对称负载造成的零序基波电压进行了理论推导,又通过大量的实验进行验证,提出简单实用的判据,并分析了可能受到影响的保护。对PT中性线断线的判据研究提供了理论依据。When PT neutral line failure, the voltage of protection relay will be comprised of fundamental zero sequence voltage and third harmonic voltage. The paper does theoretical analysis and test for this case, and proposes a practical criterion. At first, the paper outlines the current research situation for PT neutral line failure. Based on the basic hysteresis loop, it discusses the reason for the third harmonic voltage from relationship among excitation current, magnetic flux, and magnetic potential. At the same time, it deduces the fundamental zero sequence voltage generated by unbalance load when PT natural line failure. Based on lots of tests and theoretical analysis, a simple and practical criterion is proposed and the protection which would be probably affected is analyzed. The paper provides the theoretical support for research on PT neutral line failure.

关 键 词：中性线断线 三次谐波 零序基波电压 磁滞回线 零序方向保护 

分 类 号：TM77[电气工程—电力系统及自动化]