基于磁场反演的三芯电缆电流非接触测量仿真研究  

Simulation Study of Non-contact Measurement of Three-core Cable Current Based on Magnetic Inversion

作　　者：苏金刚 张鹏 黄兴旺 吕亚亚 李岩[2] SU Jingang;ZHANG Peng;HUANG Xingwang;LV Yaya;LI Yan(State Grid Hebei Electric Power Research Institute,Shjazhuang 050021,China;North China Electric Power University Baoding 071003,China)

机构地区：[1]国网河北省电力有限公司电力科学研究院,河北石家庄050021 [2]华北电力大学(保定),河北保定071003

出　　处：《河北电力技术》2024年第3期50-54,共5页Hebei Electric Power

基　　金：国网河北能源技术服务有限公司科技项目(TSS2023-08)。

摘　　要：三芯电缆因其敷设工作量小,大量应用于中低压电网线路,三芯电缆的电流检测对于研究电网电能质量具有重要意义。基于磁场的钳形电流传感器具有非接触式传感,操作方便的特点,然而正常稳态运行时三芯电缆三相电流矢量和为零,常规的基于磁场的电流传感器无法对三芯电缆的电流进行测量。因此,提出一种基于磁传感器阵列的三芯电缆电流测量方法,采用COMSOL软件得到三芯电缆周围磁场分布:磁场在周围圆周上呈周期性分布,最大值出现在距离导体最近的位置,磁场幅值受导体距离和电流频率的影响,距离导体越远,电流频率越高,磁场越小。基于该分布,通过磁传感器阵列测量结果反演计算得到三芯电缆的电流,该方法可以准确测量三芯电缆电流的大小,算例误差小于3%,为三芯电缆电流的非接触测量提供了新方法。Due to the small laying workload,three-core cables are widely used in medium and low voltage power grid lines.The load current detection of three-core cables is of great significance for studying the power quality of the power grid and improving the fault diagnosis ability of the line.However,conventional current detection devices face many challenges when measuring the current of three-core cables.The current transformer has the disadvantage of requiring fixed installation and is difficult to achieve portable measurement.The magnetic field-based clamp current sensor has the characteristics of non-contact sensing and easy operation,and is widely used on site.However,during normal steady-state operation,the three-phase current vector sum of the three-core cable is zero,and conventional magnetic field-based current sensors cannot measure the current magnitude anymore.Therefore,this article proposes a current measurement method for three-core cables based on magnetic sensor arrays.To verify the correctness of this non-contact measurement method,COMSOL software was used to obtain the magnetic field distribution around the three-core cable.The results demonstrated that the magnetic field of the three-core cable exhibited a periodic distribution around the circumference,with the maximum value appearing at the closest position to the conductor.The magnetic field amplitude was influenced by the distance from the conductor and the current frequency.The farther the distance from the conductor,the higher the current frequency,and the smaller the magnetic field.Based on this distribution,a magnetic field-based current measurement method for three-core cables is proposed.The current of the three-core cables is obtained through inversion calculation based on the measurement results of the magnetic sensor array.This method can accurately measure the current of three-core cables,with a calculation error of less than 3%,providing a new approach for non-contact measurement of three-core cable current.

关 键 词：电流监测 磁场感应 电力电缆 非接触测量 

分 类 号：TM83[电气工程—高电压与绝缘技术]