直流馈入下的输电线路距离保护动作特性分析  

Performance of Distance Protection for Transmission Lines in an HVDC/AC Interconnected Power System

作　　者：张璞[1] 王钢[1] 李海锋[1] 

机构地区：[1]华南理工大学电力学院,广东省广州市510640

出　　处：《电力系统自动化》2012年第6期56-62,共7页Automation of Electric Power Systems

基　　金：国家科技支撑计划重大项目(2006BAA02A30);国家自然科学基金资助项目(50977032);粤港关键领域重点突破项目(2009A091300011);广东省教育部产学研结合重点/重大项目(2011A090200127;2011A090200074)~~

摘　　要：直流馈入使传统输电线路距离保护的运行环境发生了改变,从而对其动作特性产生影响。结合距离保护原理的特点分析了直流馈入对输电线路距离保护影响的机理,指出其影响主要在于直流系统等值电流作用于故障过渡电阻而造成测量电抗的波动变化;基于受端电网故障引发各种换相失败情况下直流系统等值工频量电流的变化特性,从理论上分析、比较了不同输电线路情况下的距离保护受直流系统影响的特点。基于PSCAD/EMTDC仿真验证了该理论分析的正确性。High voltage direct current（HVDC） system changes the operating circumstances of the traditional distance protections for transmission lines,and thus affects its operating characteristics.Based on the distance protection theory,it has been found that the effect of HVDC system on distance protection mainly lies on the changes of measured impedance of distance relays for faults with fault resistance caused by equivalent DC system current.The characteristics of equivalent DC system power-frequency current under different types of commutation failure conditions are analyzed.The impacts on distance relays of different AC system conditions are compared.The methods are verified by PSCAD/EMTDC simulations.

关 键 词：高压直流输电 距离保护 换相失败 过渡电阻 

分 类 号：TM773[电气工程—电力系统及自动化]