A dual-mode nondestructive testing method for dielectric functionally graded insulation

Abstract

The invention discloses a dual-mode non-destructive testing method for dielectric functional gradient insulation. First, the boundaries of different density regions are obtained by segmenting the density changes at different positions inside the three-dimensional insulator, and then the geometric information is used as input, according to the measured boundary plate. The change of capacitance obtains training samples, which are trained after normalization; the functionally gradient insulator boundary capacitance matrix is ​​substituted into the trained model, and the value of the dielectric constant in the corresponding material partition inside the insulator is obtained to complete the non-destructive testing. The invention combines the advantages of high spatial resolution of ICT and direct dielectric inversion of ECT to realize the non-destructive testing requirements of dielectric functional gradient insulation with fixed shape and parameters, and solves the parameter inversion process while improving the inversion speed through machine learning algorithm nonlinear and ill-conditioned problems.

Description

technical field [0001] The invention belongs to the technical field of non-destructive testing of electric equipment, and in particular relates to a dual-mode non-destructive testing method of dielectric functional gradient insulation. Background technique [0002] In my country, flashover / breakdown faults of cast epoxy insulators in GIS occur frequently, and the problem is prominent. In recent years, the emerging "Functionally Graded Material" (Functionally Graded Material, FGM) can significantly improve the insulator flashover by adjusting the spatial distribution of dielectric parameters (relative permittivity ε and conductivity γ) to improve the uniformity of the electric field. Voltage. [0003] At present, the techniques for preparing d-FGM mainly include centrifugal method, lamination method and 3D printing. Due to the integrated molding characteristics of the manufacturing process, it is necessary to judge whether the dielectric parameter distribution inside the in...

AI Technical Summary

Problems solved by technology

Obviously, the above method is difficult to operate and cannot meet the requirements of non-destructive identification

It should be emphasized that when the spatial distribution of inhomogeneous media is more complex, destructive detection methods no longer meet the test requirements

[0004] The current non-destructive testing methods mainly include ultrasonic testing, ray testing, magnetic particle testing, acoustic emission testing, microwave non-destructive testing and other technologies. Among them, the object of ultrasonic testing is acoustic impedance, which is different from the identification of dielectric parameters, and ray testing is aimed at Objects with different densities cannot directly identify the dielectric parameters. Magnetic powder and acoustic emission technologies are not suitable for high-voltage equipment insulators composed of polymer composite materials represented by epoxy resin.

Although the microwave detection detects the dielectric parameters, the dielectric parameters in the microwave frequency band are quite different from those in the power frequency, and it is difficult to directly equivalent

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