引入电流有效值与相位突变量判据的零序反时限电流保护  

Zero Sequence Inverse-Time Current Protection with the Introduction of Current Effective Value and Phase Mutation Criterion

作　　者：鲁晓毅 郑涛[1] 代钰欣 杨畅 宋宇飞 LU Xiaoyi;ZHENG Tao;DAI Yuxin;YANG Chang;SONG Yufei(School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学电气工程学院,西安710049

出　　处：《西安交通大学学报》2024年第2期195-206,共12页Journal of Xi'an Jiaotong University

基　　金：陕西省重点研发计划资助项目(2022GXLH-01-06)。

摘　　要：针对大接地电流系统发生接地故障时,非故障线路零序反时限电流保护先于故障线路中零序电流较小一侧保护动作的问题,提出了引入零序电流有效值和相位突变量判据的零序反时限电流保护方案。首先,分析了单回线和双回线两种结构发生接地故障时,零序电流的分布特征与零序反时限电流保护的动作特性,指出相邻非故障线路零序电流可能大于故障线路零序电流,进而使零序反时限电流保护误动;随后,通过理论分析,得到故障线路中零序电流较大的一侧保护动作前后其余线路中零序电流有效值和方向的变化情况;最后,提出引入零序电流有效值和相位突变量判据的零序反时限电流保护方案,将非故障线路零序反时限电流保护重新计时。仿真结果表明:所提方案能够有效防止非故障线路零序反时限电流保护误动,从而提高了保护的选择性,且在经过渡接地时仍然适用。Aiming at the issue that zero sequence inverse time current protection of non-faulty line occurs before the protection on the side with smaller zero sequence current in the faulty line when the system with large ground current has grounding fault,a zero sequence inverse time current protection scheme introducing zero sequence current effective value and phase mutation criterion is proposed.Firstly,the distribution characteristics of zero sequence current and the operating characteristics of zero sequence inverse time current protection in the case of grounding fault in single-circuit line and double-circuit line are analyzed.It is pointed out that the zero sequence current of adjacent non-faulty lines may be greater than the zero sequence current of the faulty line,causing the misoperation of zero sequence inverse time current protection.Then,through theoretical analysis,the changes of the effective value and direction of zero sequence current in other lines before and after the protection action on the side with larger zero sequence current in the faulty line are obtained.Finally,a zero sequence inverse time current protection scheme is proposed by introducing zero sequence current effective value and phase mutation criterion,and the zero sequence inverse time current protection of non-faulty lines is re-timed.The simulation results show that the proposed scheme can effectively prevent the misoperation of zero sequence inverse time current protection of non-faulty lines,thus improving the selectivity of protection,and the proposed scheme is still suitable for transitional grounding.

关 键 词：电流保护 零序电流 反时限 突变量 选择性 

分 类 号：TM614[电气工程—电力系统及自动化]