摘要
为了提高煤矿移动变电站低压侧发生漏电故障后漏电阻的检测速度,提出了基于零序电压变化率的矿井低压供电系统漏电检测方法。通过向系统线路人为附加3个已知量级的相同电容,与线路分布电容形成并联关系,在漏电故障发生后Δt时间内流过附加3C干线上的电流与零序电压变化率呈正比例关系,利用理论计算将1140 V低压系统漏电阻的动作整定值转换为附加3C干线处的电流动作整定值。采用傅氏算法,对漏电故障发生后20 ms内各特征量的基波分量进行提取,结果表明理论计算和仿真实验数据相差不足2%,验证了该漏电检测方法的可行性,且检测速度和结构简单度均优于传统附加直流检测式漏电保护,能可靠保证系统稳定运行和人身安全。
In order to improve the detection speed of the leakage resistance after the leakage fault occurs on the low-voltage side of the mobile coal substation,a leakage detection method for the mine low-voltage power supply system based on the zero sequence voltage change rate is proposed in this paper.By artificially adding three identical capacitors of known magnitude to the system line,a parallel relationship is formed with the line distributed capacitance.The current flowing through the additional 3C trunk line inΔt time after the leakage fault is positively proportional to the change rate of zero sequence voltage.Using theoretical calculations,the operating setting value of the leakage resistance of the 1140 V low-voltage system is converted into the current operating setting value at the additional 3C main line.The Fourier algorithm is used to extract the fundamental component of each feature within 20 ms after the occurrence of the leakage fault.The results show that the difference between theoretical calculation and simulation experiment data is less than 2%,which verifies the feasibility of the leakage detection method,and the detection speed and structure simplicity are better than the traditional additional DC detection leakage protection,which can reliably ensure the stable operation of the system and personal safety.
作者
霍耀佳
马莉
李晔
吴杨
韩利
HUO Yaojia;MA Li;LI Ye;WU Yang;HAN Li(Electric Power Research Institute,State Grid Ningxia Electric Power Company,Yinchuan 750002,China)
出处
《电工技术》
2022年第3期87-90,共4页
Electric Engineering
关键词
矿井低压系统
漏电检测
附加3C
零序电压变化率
mine low-voltage system
leakage detection
additional 3C
zero sequence voltage change rate
作者简介
霍耀佳(1996-),硕士,研究方向为电力系统继电保护。
