零序导纳法馈线接地保护的研究

提出了采用测量线路零序导纳进行接地保护的新原理，讨论了直线式导纳继电器的接地保护判据。该原理克服了传统的小电流接地系统故障选线方法安装不便，可靠性不高等不足。只需测量本线路的零序电压、零序电流基波分量，适合在馈线保护中实现和就地终端单元（FTU）上安装，可行性高。经EMTP仿真分析表明：该方法具有较高的保护精度，能满足高阻接地保护的要求。

STUDY ON FEEDER GROUNDING FAULT PROTECTION BASED ON ZERO SEQUENCE ADMITTANCE

New principle for feeder grounding fault protection based on zero sequence admittance is presented in this paper.Criterions for the line ground relay with zero sequence admittance are also discussed.This principle can be applied easily in feeder relays and implemented in local control units (such as FTU) by measuring the zero sequence fundamental voltage and current.It improves the performance of traditional grounding fault relays in difficult implementation and poor reliability.This principle is verified by EMTP simulator.Results show that this protection scheme has high precision and can be used to detect high impedance grounding faults.