Non-destructive identification method for material of integral coil of distribution transformer

Abstract

The invention discloses a non-destructive identification method for a material of an integral coil of a distribution transformer. The non-destructive identification method based on the difference of attenuation coefficients of copper, steel and aluminum to X rays includes photographing the distribution transformer in a integral state by the X rays; measuring blackness of photographed negative films of the rays by a black and white densitometer; inputting measured blackness values into a computer; and computing X-ray attenuation coefficient and transillumination thickness curves, which are stored in the computer, of the copper, the steel and the aluminum corresponding to different X-ray tubes and comparing the X-ray attenuation coefficient and transillumination thickness curves with a characteristic curve of the industrial ray films, and judging whether the winding coil of the distribution transformer is made of the aluminum or the copper.

Description

technical field [0001] The invention relates to a non-destructive identification method for non-disintegrated coil materials of distribution transformers, belonging to the technical field of power transmission. Background technique [0002] In the current market economy, some short-sighted grid distribution network transformer manufacturers use aluminum enameled wire instead of copper enameled wire as the transformer coil winding in order to pursue greater profits, resulting in excessive coil volume and increased coil impedance, which increases the power consumption of the transformer. Increase the cost of power supply and seriously affect the interests of power supply enterprises. Because the transformer coil winding is wrapped with an insulating layer, even if the transformer is disassembled and not damaged, it is still impossible to identify the coil material through electrical tests and visual inspections, unless the coil is damaged and sampled for metal chemical analysi...

AI Technical Summary

Problems solved by technology

[0002] Under the current market economy, some short-sighted power grid distribution network transformer manufacturers use aluminum enameled wire instead of copper enameled wire as the transformer coil winding in order to pursue greater profits, resulting in excessive coil volume and increased coil impedance, which increases the power consumption of the transformer. Increase the cost of power supply and seriously affect the interests of power supply companies

Because the transformer coil winding is wrapped with an insulating layer, even if the transformer is disassembled and not damaged, it is still impossible to identify the coil material through electrical tests and visual inspections, unless the coil is damaged and sampled for metal chemical analysis, but this damage test It cannot be carried out one by one, otherwise the cost will be huge, and the transformer will be shut down for maintenance, which will seriously affect the grid power supply and social production and living order

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