Device for detecting external insulation of transmission lines and control method thereof

Abstract

The invention relates to a device for detecting external insulation of transmission lines and a control method thereof. The device comprises an inclined insulated support frame which supports a sample. Upper part and lower part of the sample are equipped with a high-voltage end electrode and a ground electrode respectively, wherein the high-voltage end electrode is connected with one output end of a transformer through a resistor R. A primary coil of the transformer is connected with ac power supply through a voltage regulator. A water-dripping device is arranged above the sample and an antenna is arranged in front of a sample surface, wherein the antenna is connected with a filter amplifier circuit. The filter amplifier circuit is connected to a computer through a data acquisition card. The method comprises: putting the sample on the insulated support frame and connecting the sample to the high-voltage end electrode and the ground electrode, electrifying the sample, dripping water upon the sample surface, receiving electromagnetic wave signals, drawing a three-dimension spectrum of the electromagnetic wave signals, calculating a vacancy rate lambda with a formula, drawing a two-dimension spectrum, drawing a discharging recurrence plot and calculating a recurrence rate, and determining a hydrophobicity level of the sample. The device and the method can decrease external interference and provide high accuracy, and can visually, clearly and accurately reflect changing conditions of hydrophobicity of the insulator surface.

Description

technical field [0001] The invention relates to a device for detecting the external insulation of a power transmission line. In particular, it relates to a device for detecting the external insulation of a transmission line and a control method thereof, which use a dynamic dripping method to obtain electromagnetic wave signals emitted by discharges corresponding to different hydrophobicities, and analyze the signal characteristics to identify the hydrophobicity of insulators. 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 have been widely used in my country's power grids due to their advantages such as high pollution flashover and wet flashover voltages and light weight. With the gradual increase of the voltage level of my country's power grid...

AI Technical Summary

Problems solved by technology

[0017] 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 evaluating the hydrophobicity of insulators under laboratory conditions and offline conditions. Not suitable for surface hydrophobicity detection of online insulators

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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