交叉互联高压电缆护层保护器故障对同回路两端护层电流相量差的影响  

Influence of the Sheath Voltage Limiter Fault on the Sheath Current Phasor Difference Between the Two Ends in the Same Sheath Loop in Cross-bonded HV Cables

作　　者：刘福源 王航 夏湛然 杨斌 杨帅 周承科 LIU Fuyuan;WANG Hang;XIA Zhanran;YANG Bin;YANG Shuai;ZHOU Chengke(Hubei Engineering Research Center for Safety Monitoring of New Energy and Power Grid Equipment,Hubei University of Technology,Wuhan 430068,China;Electrical Cable Operation and Maintain Branch of Wuhan Power Supply Company,State Grid Hubei Power Supply Company,Wuhan 430024,China;School of Engineering and Built Environment Glasgow Caledonian Uni-versity,Glasgow,G40BA,UK;School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China)

机构地区：[1]湖北工业大学新能源及电网装备安全监测湖北省工程研究中心,武汉430068 [2]国网湖北电力公司武汉供电公司电缆运检室,武汉430024 [3]格拉斯哥卡里多尼亚大学工程与建筑环境学院,英国格拉斯哥G40BA [4]武汉大学电气与自动化学院,武汉430072

出　　处：《高电压技术》2023年第3期1244-1253,共10页High Voltage Engineering

基　　金：湖北省电力公司科技项目(SGTYHT/21-JS-223);湖北工业大学科研启动基金(HSQD2020020)。

摘　　要：高压电缆护层保护器故障对同护层回路两端护层电流相量差的影响规律是制定护层接地故障判据的理论基础。为识别护层保护器故障,在器件级别构建了电容和非线性电阻并联的护层保护器故障等效电路,在系统级别构建了三相9段交叉互联电缆在护层保护器正常和故障时的数学物理模型,推导了护层保护器故障阻抗与同护层回路两端直接接地点护层电流相量差的传递函数。以110 kV电缆为仿真案例,结果表明:同回路两端护层电流相量差既可以区分正常和故障状态,又可以区分不同位置护层保护器金属性接地故障;护层电流相量差相角对金属性接地和低阻接地敏感,同回路首端和末端护层保护器发生100Ω接地故障时,护层电流相量差相角偏差范围分别为17.9°~24.9°和33.4°~51.1°;216Ω接地故障时护层电流相量差相角偏差范围分别为9.4°~13.6°和12.4°~17.5°。护层电流相量差受电缆3小段不等长和相电流影响显著,受地阻抗和相电压波动影响不显著。The influence of sheath voltage limiter faults on sheath current phasor difference between the two ends in the same sheath loop of high voltage cables is the theoretical base of the fault diagnosis criteria.At device level,the equiva-lent circuit of sheath voltage limiter consists of a parallel capacitance and nonlinear resistance is modelled in this paper.At system level,a mathematical and physical model of cross-bounded cable system under normal and faulted condition is formulated,then the transfer function between the fault impedance of sheath voltage limiter and the phasor difference of the sheath current measured on the two solid grounding points in the same sheath loop is derived therefore.The results of the simulation on 110 kV cable system show that not the faulted sheath voltage limiter can be distinguished by the sheath current phasor difference under metallic grounding faults.Phase of the sheath current phasor difference is sensitive to metallic and low resistance grounding faults,whilst its the phasor deviation of the sheath current phasor difference be-tween 100 ohms grounding fault in left and right sheath voltage limiter and normal condition range from 17.9º~24.9ºor 33.4º~51.1º;and 9.4º~24.9 or 9.4º~24.9ºunder 216 ohms grounding fault.Besides,unequal length of minor sections and phase current fluctuation have significant influence on the sheath current phasor difference,and the grounding resistance and phase voltage fluctuation have insignificant impact on the sheath current phasor difference.

关 键 词：高压电缆 护层电流 相量差 交叉互联 护层保护器故障 接地故障 

分 类 号：TM75[电气工程—电力系统及自动化]