Nondestructive testing system for defects of composite insulator based on reflecting property of microwave band

Abstract

The invention relates to a nondestructive testing system for defects of a composite insulator based on the reflecting property of a microwave band. The system comprises a femtosecond laser source, a wave guide device, a switch port, an oscillograph and a data analysis module, wherein the femtosecond laser source is used for generating detection signals; the wave guide device is used for connecting the femtosecond laser source with the switch port; the switch port comprises a partial wave mirror surface with bidirectional permeability to microwave band signals and is used for separating incident signals and reflected signals; and the data analysis module is used for carrying out time-domain analysis on the incident signals and the reflected signals, simulating and calculating basic conditions of a composite insulator at a tested point so as to realize defect determination. By utilizing a new composite insulator defect detection manner, internal defects of the composite insulator can be effectively detected.

Description

technical field [0001] The invention relates to a non-destructive detection technology for composite insulator defects, in particular to a non-destructive detection system for composite insulator defects based on microwave band reflection characteristics. Background technique [0002] The physical properties of composite insulators greatly affect the electrical properties of the composite insulators. Once the sheath or mandrel has internal or skin defects such as cracks, air gaps, and penetrations, it will easily lead to increased leakage current or even flashover in power grid lines. At present, the common composite insulator defect detection methods are divided into online method and offline method. Among them, the infrared detection method in the online method and the continuous wave microwave detection method in the offline method are two commonly used methods in the prior art. [0003] Patent CN 103760480 B discloses a composite insulator fault judgment method using i...

AI Technical Summary

Problems solved by technology

The continuous wave microwave detection method is a microwave detection method based on a continuous wave signal source. After the reflected signal is rectified, only the intensity information is retained, and other information such as phase and waveform distortion cannot be read.

At the same time, since the continuous wave detection is to collect and analyze the steady-state reflection signal, this method cannot identify and detect transient information such as the propagation time of the microwave in the medium

Because of the above characteristics, the continuous wave microwave detection method cannot accurately judge the defect type, interlayer thickness and other information

In addition, there is no calculation process such as convolution and denoising in continuous wave signal analysis, which will cause huge misjudgment due to various small factors on the detection site

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