An improved detection method for the aging degree of composite insulators based on modulated photothermal radiation technology

Abstract

The invention relates to an improved detection method for the aging degree of composite insulators based on modulated photothermal radiation. The method uses modulated photothermal radiation technology to respectively measure the heat of the aging layer area on the surface of the composite insulator and the internal unaged layer exposed after removing the aged layer on the surface. Diffusivity, using the measured ratio of the thermal diffusivity of the surface aging layer to the thermal diffusivity of the internal unaged layer to judge the aging degree of the composite insulator. This method overcomes the influence of the difference in initial thermal diffusivity of composite insulators of different specifications and models and the lack of accurate data on the detection method of evaluating the aging degree of composite insulators by using thermal diffusion characteristics, and improves the detection accuracy of evaluating the aging degree of composite insulators by using thermal diffusion characteristics .

Description

technical field [0001] The invention relates to a method for detecting the aging degree of composite insulators, in particular to a method for evaluating the aging degree of composite insulators by measuring the ratio of thermal diffusivity between the aging layer area and the inner unaged layer area of ​​the composite insulator based on modulated photothermal radiation, which belongs to high voltage field of electrical testing. Background technique [0002] High-temperature vulcanized silicone rubber composite insulators are widely used in high-voltage transmission power systems and play an important role in insulating and supporting transmission lines. However, with the increase of the running time of the hanging grid, the surface of the high-temperature vulcanized silicone rubber composite insulator gradually ages, resulting in the loss of hydrophobicity on the surface of the insulator, and the deterioration of pollution flashover resistance, which brings serious safety h...

AI Technical Summary

Problems solved by technology

However, these detection methods have some limitations

For example, the judgment of the appearance by human eyes and the artificial classification of the surface state of water droplets attached to the composite insulator by the water spray classification method are greatly affected by subjective factors and are not easy to quantify; the measurement of leakage current and thermal stimulation current requires complicated construction. The experimental system, in which the measurement of the thermal stimulation current even needs to be placed in a vacuum environment, is inconvenient to operate

However, modern material microscopic characterization techniques usually cannot meet the needs of low-cost, quantitative and rapid test and evaluation of the aging degree of composite insulators

[0004] Recently, the invention patent of Chinese patent application No. 201810630895.5 "a method for evaluating the aging degree of composite insulators based on laser irradiation" and the invention patent of Chinese patent application No. 201810630712.X "a method for detecting the aging degree of composite insulators based on continuous laser irradiation" It is proposed to evaluate the aging degree of composite insulators by measuring the thermophysical properties (thermal diffusivity) of composite insulators, but the detection method of composite insulator aging degree based on the change of thermophysical properties is limited by the thermophysical properties of the composite insulator before use (initial) Influenced by parameter values, and usually the thermophysical parameter values ​​of the composite insulator before use are not accurately determined (unknown), which leads to errors in the evaluation of the aging degree and affects the determination accuracy of the aging degree

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