低频三维磁场测量系统研制  

Development of Low-frequency Three-dimensional Magnetic Field Measurement System

作　　者：李祥麟 吴静[1] 金海彬[2] 李怡濛 LI Xiang-lin;WU Jing;JIN Hai-bin;LI Yi-meng(Beihang University,Beijing 100191,China;Beijing Orient Institute of Measurement and Test,Beijing 100086,China)

机构地区：[1]北京航空航天大学,北京100191 [2]北京东方计量测试研究所,北京100086

出　　处：《宇航计测技术》2021年第1期33-37,共5页Journal of Astronautic Metrology and Measurement

基　　金：国家自然科学基金项目(51777006)资助。

摘　　要：低频10Hz~20kHz的电磁波在气象观测、地质勘探、远距通信等领域具有广泛应用。为了监测该频段的电磁辐射,本文设计了三轴正交方形天线用于测量低频磁场,采用基于AD797与OP27的双级放大电路对磁场感应电压信号进行调理和放大,采用NI-9222数据采集卡实现对信号波形进行采集,利用短时傅里叶变换对信号进行时频分析。所研制的测量系统可测量0.15pT~340nT的时变磁场,电路仿真和实际测试结果表明系统具有良好的幅频特性,能够有效监测出电网变电站附近的弱低频电磁辐射。Electromagnetic waves in the range of 10 Hz to 20 kHz are widely used in meteorological observation,geological exploration,long-distance communication and other fields.In order to monitor the electromagnetic radiations in this band,a three-axis orthogonal loop antenna is designed.A two-stage amplifier circuit based on AD797 and OP27 is used to condition and amplify the voltage signal of induction coil.The NI-9222 data acquisition card is used to acquire magnetic field signal,and the short-time Fourier transform is used to analyze the time-frequency characteristics of the signal.The developed system can measure time-varying magnetic field of 0.15 pT~340 nT.The circuit simulation and practical test results show that the system has a good amplitude-frequency characteristic and can effectively monitor the weak low-frequency electromagnetic radiations near the power substation.

关 键 词：超低频辐射 磁感应传感器 信号处理 三维磁场测量 

分 类 号：TM937[电气工程—电力电子与电力传动]