瞬变电磁接收线圈响应过程分析: 以阻尼比与谐振频率为例  

Response analysis of transient electromagnetic hollow coil:Insights from damping ratio and resonant frequency

作　　者：孙怀凤[1,2] 许伟强 张诺亚 柳尚斌 刘锐[1,2] 刘玉超 周正 SUN HuaiFeng;XU WeiQiang;ZHANG NuoYa;LIU ShangBin;LIU Rui;LIU YuChao;ZHOU Zheng(State Key Laboratory for Tunnel Engineering,Shandong University,Jinan 250061,China;Institute of Geotechnical and Structural Underground Engineering,Shandong University,Jinan 250061,China)

机构地区：[1]山东大学隧道工程灾变防控与智能建养全国重点实验室,济南250061 [2]山东大学岩土与地下工程研究院,济南250061

出　　处：《地球物理学报》2024年第11期4360-4371,共12页Chinese Journal of Geophysics

基　　金：国家重点研发计划(2023YFC2907103);泰山学者工程资助。

摘　　要：以电磁感应为原理的接收线圈是测量瞬变电磁信号的核心器件, 研究其响应特性对于瞬变电磁装备研发与校准具有重要意义.本文基于空心线圈的传感器方程与瞬变电磁的理论信号, 分析了阻尼比与谐振频率这两个关键参数对瞬变电磁感应线圈响应过程的影响规律, 并给出了选取建议.在讨论阻尼比选取的过程中提出了两种定量计算方法, 首先计算了纯二次场接收时间中不同阻尼比的累计积分误差, 发现在阻尼比取0.6411时整体积分误差最小;但考虑到瞬变电磁方法观测信号应尽早摆脱震荡达到稳定输出的特点, 又引入了线圈响应值与理论值的比值η曲线以及稳定截止时间参数tc, 比较不同阻尼比下进入稳定输出的时间点, 发现能够最早达到稳定输出的阻尼比为0.9118, 并将其作为本文的阻尼比选取建议.针对线圈谐振频率, 通过对比不同谐振频率下的线圈输出曲线发现随着线圈谐振频率增加, 输出曲线的响应速度与完成震荡过程的速度均会提升, 可以提前到达稳定截止时间, 能够提前观测瞬变电磁有效信号.还发现随着谐振频率的增加, 曲线的响应速度不断加快, 且线圈中接收到的能量随之增加, 但通过提高线圈谐振频率来提升响应速度或者增加接收能量都存在明显的边际递减效应, 因此建议线圈谐振频率设置在增速拐点之上以保证线圈的综合性能.本文研究对瞬变电磁接收线圈传感器设计具有参考价值.The receiving coil based on electromagnetic induction is the core device for measuring transient electromagnetic signals, and studying its response characteristics is of great significance for the development and calibration of transient electromagnetic equipment. This article analyzes the influence of two key parameters, damping ratio and resonant frequency, on the response process of transient electromagnetic induction coil based on the sensor equation of hollow coil and the theoretical signal of transient electromagnetic, and provides selection suggestions. In the process of discussing the selection of damping ratio, two quantitative calculation methods were proposed. Firstly, the cumulative integration error of different damping ratios in the pure secondary field receiving time was calculated, and it was found that the overall integration error was the smallest when the damping ratio was set to 0.6411;However, considering the characteristic that transient electromagnetic methods should eliminate oscillations and achieve stable output as soon as possible, the ratio of coil response value to theoretical value has been introduced η By comparing the time points at which stable output occurs under different damping ratios using the curve and stable cutoff time parameter tc. It was found that the damping ratio that can reach stable output earliest is 0.9118, which was used as a recommendation for selecting the damping ratio in this paper. Regarding the resonant frequency of the coil, by comparing the output curves of the coil at different resonant frequencies, it was found that as the resonant frequency of the coil increases, the response speed of the output curve and the speed of completing the oscillation process will both increase, which can advance to the stable cutoff time and observe the transient electromagnetic effective signal in advance. In addition, it was found that as the resonant frequency increases, the response speed of the curve continues to accelerate, and the energy received in the coil increase

关 键 词：瞬变电磁 空芯线圈 阻尼比 谐振频率 

分 类 号：P631[天文地球—地质矿产勘探]