Nuclear magnetic resonance sensor used for nondestructive aging resonance of umbrella skirt of composite insulator

Abstract

The invention discloses a nuclear magnetic resonance sensor used for the nondestructive aging resonance of an umbrella skirt of a composite insulator. The sensor comprises a permanent magnet structure and a plane radio-frequency coil, wherein the permanent magnet structure mainly consists of two cylindrical permanent magnet sheets of same specification, the two cylindrical permanent magnet sheets are oppositely and coaxially arranged, and the permanent magnet structure is used for producing a static state main field B0; and the permanent magnet structure is provided with a slide mechanism, so that the distance between the permanent magnet sheets can be adjusted so as to adapt to umbrella skirts of different thickness. The plane radio-frequency coil is formed by two spiral coils which are connected in series on a plane according to the reverse direction of the magnetic field, and the plane radio-frequency coil is used for generating radio-frequency magnetic field B1 orthometric with the main magnetic field in a target region, and detecting return signals produced by a sample to be tested. During the aging detection of the umbrella skirt of the composite insulator, the slide mechanism is adjusted to enable the sensor to clamp the umbrella skirt to be tested, so that the transverse relaxation time T2 of the umbrella skirt can be measured, and further, the aging degree of the umbrella skirt can be judged according to the transverse relaxation time T2. The open-type nuclear magnetic resonance sensor has the advantages of small volume, light weight, and convenience in engineering field detection.

Description

technical field [0001] The invention relates to a nuclear magnetic resonance sensor, in particular to a nuclear magnetic resonance sensor used for non-destructive detection of composite insulator shed aging. Background technique [0002] Composite insulators are widely used in high-voltage transmission lines due to their light weight, high mechanical strength, not easy to break, and good pollution resistance. The composite insulator shed is the outer insulation of the composite insulator, used to protect the mandrel from the erosion of the atmosphere, provide the necessary creepage distance, and improve the pollution resistance. During the operation of the hanging grid, the composite insulator shed will experience aging or breakdown problems under the overvoltage of the power grid and the erosion of the natural environment, which poses a potential threat to the reliability of power supply. Therefore, the online non-destructive testing of composite insulator shed materials is...

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Problems solved by technology

However, the research is only at the laboratory stage, lacking the analysis of complex surfaces in complex situations; although the feasibility prediction of on-site online testing has been made, it has not been put into practice

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