作者：张睿哲¹, 周恺¹, 任志刚¹, 蔡瀛淼¹, 李春生¹, 孙洪宇², 黄松岭²

作者单位：1. 国网北京电科院，北京 100071;
2. 清华大学电机工程与应用电子技术系 电力系统及大型发电设备安全控制和仿真国家重点实验室，北京 100084

关键词：输电杆塔;接地扁钢;土壤密度;超声SH导波;缺陷检测

摘要：

对接地电极进行缺陷检测一般需要进行实际的开挖验证，这会消耗大量的人力、物力和财力。因此，亟需一种有效的免开挖或少开挖的接地极缺陷检测方法。该文通过构建接地极超声导波检测的有限元模型对导波的传播进行计算，并考虑到土壤带来的影响，研究在土壤密度不同时超声传播的特点以及接收信号的特征。随着土壤密度的增大，超声信号的强度随之减小，并随着时间的推移快速衰减。此外，分析不同宽度接地极中水平剪切（SH）导波的特点，并对辐射极上不同类型缺陷的反射回波进行研究。不同接地极宽度和缺陷类型的超声信号具有明显不同，从而可以作为缺陷检测和接地极探测的依据。因此，基于SH超声导波的缺陷检测方法在检测接地扁钢腐蚀损伤方面具有潜在的实际应用价值。

Research on detection method of SH guided wave corrosion defects in grounding flat steel of transmission tower
ZHANG Ruizhe¹, ZHOU Kai¹, REN Zhigang¹, CAI Yingmiao¹, LI Chunsheng¹, SUN Hongyu², HUANG Songling²
1. State Grid Beijing Electric Power Research Institute, Beijing 100071, China;
2. State Key Laboratory of Power System and Generation Equipment, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China
Abstract: Defect detection of ground electrodes generally requires actual excavation verification, which consumes workforce, material, and financial resources. Therefore, there is an urgent need for an effective method for detecting ground electrode defects without or with less excavation. In this paper, the propagation of guided waves is calculated by constructing a finite element model for ultrasonic guided wave detection of grounding electrodes, and the influence of soil is considered, that is, the characteristics of ultrasonic propagation and the characteristics of received signals when the soil density is different are studied. As the density of the soil increases, the intensity of the ultrasonic signal decreases and decays faster over time. Besides, the characteristics of horizontal shear (SH) guided waves in ground electrodes of different widths are analyzed. The reflected echoes of different types of defects on the radiating electrodes are studied. The ultrasonic signals of different ground electrode widths and defect types are significantly different, which can be used as a basis for defect detection and ground electrode detection. Therefore, the acoustic pulse-echo method based on ultrasonic guided waves has potential practical application value in detecting the corrosion damage of grounded flat steel.
Keywords: transmission tower;ground flat steel electrode;soil density;ultrasonic SH guided wave;defect detection
2021, 47(8):51-57  收稿日期: 2020-09-30;收到修改稿日期: 2020-11-10
基金项目: 国网北京市电力公司科技项目（52022319005k）
作者简介: 张睿哲(1989-),男,山西长治市人,硕士,主要研究方向为高压设备状态监测及故障诊断
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