Composite insulator hydrophobicity evaluating device and method based on dynamic drip ultrasound characteristic

Abstract

The invention discloses a composite insulator hydrophobicity evaluating device and method based on a dynamic drip ultrasound characteristic. The composite insulator hydrophobicity evaluating device is an inclined insulation bracket for supporting a test sample, the upper part and the lower part of the test sample are respectively and correspondingly provided with a high-voltage end electrode and a low-voltage end electrode, the high-voltage end electrode is connected with the anode of a high-voltage DC power supply through a resistor R, the low-voltage end electrode is connected with the ground electrode of the high-voltage DC power supply, a drip device used for dropping water on the surface of the test sample, which is positioned between the high-voltage end electrode and the low-voltage end electrode, is arranged above the test sample, an ultrasonic sensor used for receiving an ultrasonic signal generated when discharge is caused on the surface of the test sample by water drops is arranged in front of the surface of the test sample, and the output end of the ultrasonic sensor is sequentially connected with a filter and amplification circuit, an oscillograph and a computer. The composite insulator hydrophobicity evaluating method comprises the steps of: placing the test sample on an insulation bracket, installing the high-voltage end electrode and the low-voltage end electrode; dropping the water drops on the surface of the test sample and electrifying; and receiving a signal and substituting into a formula to determine the hydrophobicity level of the test sample. According to the invention, change conditions of hydrophobicity of the surface of an insulator can be visually, clearly and accurately reflected.

Description

technical field [0001] The invention relates to a method for evaluating the hydrophobicity of a composite insulator. In particular, it relates to a device for evaluating the hydrophobicity of composite insulators based on dynamic dripping ultrasonic characteristics, which uses the dynamic dripping method to obtain the discharge ultrasonic signal characteristics corresponding to different hydrophobicities, and analyzes the relationship between the ultrasonic signal features to identify the hydrophobicity of the insulator. method. Background technique [0002] Composite insulators have been used as external insulation for nearly 40 years. Composite insulators are used in power grids in many countries and regions, and the number of grid-connected insulators is still gradually increasing. Composite insulators are widely used in my country's power grid because of their advantages such as pollution flashover, high wet flashover voltage and light weight. With the gradual increase...

AI Technical Summary

Problems solved by technology

[0017] However, there are many shortcomings in the existing methods for evaluating the surface hydrophobicity of composite insulators: ① Although the static contact angle method has high measurement accuracy, it requires a strict test environment and is mainly used for insulator hydrophobicity under laboratory conditions and offline conditions. Evaluation, not suitable for surface hydrophobicity testing of insulators in-line

② Some liquids used in the surface tension method are harmful to the human body, so this method has not been widely used at present

③ Although the water spray classification method is fast and simple to operate, it mainly relies on human comparison and classification, which is greatly affected by human subjective factors, and cannot quantitatively evaluate the hydrophobicity of the insulator surface

④At present, most of the research on leakage current stays at the theoretical stage, and most of them focus on the detection of operating conditions. So far, there is no effective method for quantitatively evaluating the hydrophobicity of composite insulators based on leakage current.

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