高压电缆铝护套焊缝缺陷ACFM检测方法及检测系统的研究

针对在氩弧焊型高压电缆铝护套焊接过程中易出现表面漏焊、埋藏未焊透和焊穿等缺陷的问题，提出了焊缝缺陷的交流电磁场检测（alternating current field measurement, ACFM）方法。首先，利用COMSOL多物理场仿真软件建立高压电缆铝护套焊缝缺陷ACFM模型，研究U形磁芯上的励磁线圈在不同类型铝护套焊缝缺陷区域产生的感应电流的密度分布特点和和磁场信号特征；其次，设计了可获取缺陷长度和深度信息的正交式接收线圈，制作了带有缺陷的电缆铝护套焊缝试件及ACFM实验平台；最后，进行了不同类型铝护套焊缝缺陷的检测及结果分析。实验结果表明，ACFM方法能够有效用于3 mm厚的高压电缆铝护套焊缝表面漏焊和焊穿缺陷的检测，并且能够有效识别埋深为2 mm，长、宽、深分别为10，0.3，1 mm的埋藏未焊透缺陷。研究结果为高压电缆铝护套焊缝缺陷的识别和焊缝质量的评价提供了重要参考。

Research on ACFM detection method and detection system for weld defects of aluminum sheath of high voltage cable

In view of the defects such as surface missed welding, buried incomplete penetration and weld penetration during the welding of aluminum sheath of argon arc welded high voltage cable, analternating current field measurement (ACFM) method for weld defects was proposed. Firstly, the ACFM model of weld defect of aluminum sheath of high voltage cable was established by using COMSOL multi-physical field simulation software, and the density distribution characteristics of induced current generated by an exciting coil on a U-shaped core and magnetic field signal characteristics of different types of defect areas of aluminum sheath weld were studied; secondly, an orthogonal receiving coil was designed to obtain the information of length and depth of defects, and the cable aluminum sheath weld specimen with defects and ACFM experimental platform were made; finally, the weld defects of different types of aluminum sheath were detected and the results were analyzed.The experimental results showed that ACFM method could be effectively used to detect the surface missed welding and weld penetration defects of aluminum sheath of high voltage cable with a thickness of 3 mm, and could effectively identify the buried incomplete penetration defects with a buried depth of 2 mm and a length, width and depth of 10, 0.3 and 1 mm respectively.The research results provide an important reference for the identification of weld defects and the evaluation of weld quality of aluminum sheath of high voltage cable.