基于GPR偏移成像处理的杆塔接地体缺陷检测

Defect Detection of Pole Tower Grounding Body Based on GPR Offset Imaging

输电线路作为电能传输的关键通道,通过杆塔架设于野外开阔地区,极易遭受雷害进而影响电力系统的安全稳定。作为线路杆塔的防雷手段,接地材料常年埋于地下,难以对其存在的缺陷进行检测。为此,在传统探地雷达检测方法的基础上,研究脉冲探地雷达成像特性,提出了一种基于探地雷达(ground penetrating radar, GPR)成像处理的线路杆塔接地体缺陷检测技术,通过Stolt偏移法对雷达探测回波进行成像,并结合图像二值化、膨胀腐蚀算法对雷达偏移图像进行处理,利用Canny算子开展杆塔接地体缺陷的识别、诊断工作。仿真与沙池实验结果表明,所提出的接地体缺陷检测技术能在不开挖不停电情况下准确对接地体是否存在断裂、破损缺陷进行识别诊断,有助于实际线路防雷检测工作的进行。

As a key channel for power transmission, power transmission lines are erected in open areas through poles, which are extremely vulnerable to lightning and affect the safety and stability of power systems. At the same time, as a lightning protection method for line towers, grounding materials are buried underground all year round, making it difficult to detect their defects. Consequently, we investigated the imaging characteristics of pulsed ground penetrating radar on the basis of traditional ground penetrating radar detection methods, and proposed a ground renetrating radar(GPR) imaging processing method for detecting faults in the grounding tower of line poles. The Stolt migration method was used to image the radar detection echo, and the radar offset image was processed with the image binarization and expansion and corrosion algorithm. The Canny operator was used to carry out the pole fault identification and diagnosis. The simulation and sand pool experiment results show that the proposed grounding body defect detection technology can be employed to accurately identify whether the grounding body is broken or damaged without digging or power failure, which is helpful for the actual line lightning detection work.