Reconstruction method for internal defect of three-post insulator based on ultrasonic scanning principle

Abstract

The invention discloses a reconstruction method for an internal defect of a three-post insulator based on an ultrasonic scanning principle. The method comprises the steps of S1, constructing an ultrasonic detection system; S2, enabling the ultrasonic detection system to detect similar positions of the three-post insulator and record ultrasonic reflection echo information of each detection position; S3, judging the ultrasonic reflection echo information of each detection position by using an analogy method to determine the defect position; S4, enabling the ultrasonic detection system to performultrasonic scanning nearby the defect position, and record the ultrasonic reflection echo information of each detection position; and S5, constructing the corresponding relation among the ultrasonicreflection echo information, the defect depth and the defect size, and obtaining a defect reconstruction schematic diagram based on the detection result of each scanning position. By adopting the reconstruction method for the internal defect of the three-post insulator based on the ultrasonic scanning principle disclosed by the invention, identification and localization and defect quantization canbe performed efficiently, accurately and intuitively on the internal defect of the three-post insulator.

Description

technical field [0001] The invention relates to the field of power transmission and transformation insulation equipment, in particular to a method for reconstructing internal defects of a three-pillar insulator based on the principle of ultrasonic scanning. Background technique [0002] Three-pillar insulators are key electrical components in gas-insulated metal-enclosed transmission lines (GILs), serving as electrical insulation and mechanical support. The three-pillar insulator is made by mixing epoxy resin, curing agent (usually acid anhydride) and filler (alumina powder) into a mold with aluminum alloy inserts and curing at high temperature. If the quality control of the curing process is not good, the three-pillar insulator is The epoxy material of the insulator and the aluminum alloy will have defects such as shelling, interlayer, and loose bonding (these defects are collectively referred to as internal defects), especially the solid epoxy material and the grounding in...

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Problems solved by technology

[0003] At present, the defect detection of three-pillar insulators is generally in the factory test stage. Two detection methods are commonly used: one is the direct method, which uses industrial digital X-ray imaging technology, and judges the insulator by comparing the light and shade of the X-ray penetrating wave on the display panel. Whether there are defects such as air gaps, cracks, and interlayers inside, the advantage is that the defects are visualized and the detection efficiency is high, but the detection sensitivity for cracks with small widths is not high, and X-ray radiation is harmful to the human body. X-ray imaging machines Expensive, bulky, unable to detect insulators in the process of assembly and maintenance; the other is the indirect method, which uses power frequency partial discharge detection methods, including pulse current method, UHF method, acoustic detection method, optical detection method The most widely used method is the pulse current method, but it is difficult to accurately identify the defect location and defect shape of the insulator.

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