双频涡流检测系统的设计-电测与仪表.PDFVIP

双频涡流检测系统的设计* 乔天骄，黄松岭，赵伟，王珅 （清华大学 电机系 电力系统国家重点实验室，北京 100084） 摘 要：双频涡流检测是涡流检测中的研究热点。简要的分析了双频在涡流检测中的必要性，介绍了涡流检 测的基本原理，叙述了双频涡流检测系统的整体方案，并分别从双频激励源的设计、信号检测电路的分析、 双频信号提取电路的分析和信号的处理方法等方面介绍了双频涡流检测系统的设计过程。以涡流检测的主 要干扰因素之一提离效应为例验证了双频涡流检测对于干扰因素抑制的有效性。 关键词：涡流检测；双频激励；正交锁相放大器；提离效应 中图分类号：TG115.28 文献标识码：A 文章编号： The Design of the Dual-Frequency Eddy Current Testing System Qiao Tianjiao, Huang Songling, Zhao Wei, Wang Shen (State Key of Power Systems, Dept. of Electrical Engineering, Tsinghua University, Beijing 10084, China) Abstract: Dual-frequency eddy current testing is a hot spot of eddy current testing. This work briefly analyzes the necessity of dual-frequency in eddy current testing, introduces the basic principle of eddy current testing, describe the overall scheme of dual-frequency eddy current testing system, and introduces the design process of dual- frequency eddy current testing system, including the design of the dual-frequency excitation source, the analysis of the signal detection circuit, analysis of the dual-frequency signal extraction circuit and the method of signal processing. This work also verifies the effectiveness of dual-frequency eddy current testing for inhibiting interference factors, which is one of the main interference factors of eddy current testing. Keywords: eddy current testing, dual-frequency excitation, orthogonal lock-in amplifier, Lift-off effect 0 引言 磁导率电导率的变化、探头的提离效应、检测管道 涡流检测是当今五大常规无损检测方法之 支持板等干扰，而常规的涡流检测采用单一频率获 一，它是以电磁感应原理为基础，将载有交变电流 取的信息量有限，不能有效的抑制干扰因素。多频 的检测线圈靠近金属被测导体时，由于激励线圈产 涡流检测技术采用多频率激励同时工作，这种方法 生交变磁场的作用，金属被测导体会感应出涡流， 比单频涡流检测能获取更多的数据，加以分析可以 涡流又将