中文摘要：

分析了输电线路在各种运行方式情况下零序电抗继电器（即以零序电流为极化量的接地电抗继电器）的动作特性，结果表明其位于送电侧、受电侧以及线路空载时具有不同的保护性能，同时在线路出口故障时存在死区。以负序电流作为极化量，利用保护安装侧电源电压相位判定同相点，实现了接地电抗继电器的改进动作判据。新判据解决了出口高阻故障保护拒动问题，提高了受电侧或空载线路上的接地电抗继电器抗高阻故障的能力。理论分析与仿真测试验证了接地电抗继电器改进判据具有较高的可靠性与灵敏性。

英文摘要：

The action characteristics of zero- sequence reac.tance relay,i.e, the earthing fault reactance relay with zero- sequence current as polarization,are analyzed in various operating cases. Theoretical analysis indicates that ,its performance is different when it locates at sending side ,receiving side,or on no -load transmission line. Furthermore,the nearby fault cannot be protected. An improved criterion is proposed,which takes negative-sequence current as polarization and utilizes phase difference between power supply voltage vector and negative- sequence current vector to estimate the in- same- phase point. The detection ability of high resistance fault is improved greatly. Theoretical analysis and simulative tests prove that,the relay with improved criterion has better reliability and sensitivity.