Dielectric window for measuring gas-insulated combined electrical apparatus partial-discharge ultrahigh-frequency signal

Abstract

The invention discloses a dielectric window for measuring gas-insulated combined electrical apparatus partial-discharge ultrahigh-frequency signal and pertains to the field of electric equipment insulation detection technology. The dielectric window consists of a metal connecting cavity, an insulated dielectric plate, an antenna array, a bolt and a metal protective cap; wherein, the front end of the metal connecting cavity is fixedly connected with an opening hole on the shell of the gas-insulated switchgear through welding and the rear end of the metal connecting cavity is connected with a metal flange disc for fixing the insulated dielectric plate; the antenna array consists of orderly distributed antenna groups and is embedded in the insulated dielectric plate; the metal protective cap fixes the insulated dielectric plate on the metal connecting cavity through the bolt. The invention combines the advantages of the internal sensor method and the external sensor method and can amplify 300MHz to 3GHz electromagnetic wave signals. The invention has strong anti-inference ability, high sensitivity, no impact on GIS internal insulation and sealing property in the detection process and high safety reliability.

Description

technical field [0001] The invention belongs to the technical field of electrical equipment insulation detection, and in particular relates to a dielectric window for measuring partial discharge ultra-high frequency signals of gas-insulated combined electric appliances. Background technique [0002] Gas-insulated combined electrical appliances (GIS) have the advantages of small footprint and high operational reliability, but because of the latent insulation defects in the manufacturing or long-term operation process, they will still cause failures and gradually expand, often leading to major accidents. occur. The most common electrical failure characteristic of GIS is the occurrence of partial discharges before complete breakdown or flashover of the insulation. By detecting the partial discharge of GIS, it can reflect the insulation status of GIS, discover the insulation defects in GIS in advance, and even determine the location of defects, which is of great significance to...

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Problems solved by technology

[0004] There are two main methods for GIS partial discharge UHF sensing at home and abroad. One is the in-body sensing method. This method is to place the sensor inside the GIS shell, so it is not easily affected by external electromagnetic interference, and the anti-interference It has strong capability and high sensitivity, but it needs to be installed in the GIS body. The sensor is in direct contact with the gas in the GIS, which may affect the reliability of GIS operation. The safety and reliability are poor, and the sensor can only be inserted during GIS manufacturing or maintenance. The installation is inconvenient, which limits the application of this method; the second is the in vitro sensing method, which is to place the sensor outside the GIS shell, usually on the outer edge of the insulator, so as to receive the electromagnetic wave signal generated by the partial discharge , this method is easy to install, flexible in detection, high in safety and reliability, and can quickly locate the partial discharge source. However, since the sensor is installed outside the GIS shell, it is easily affected by external UHF interference signals, and its anti-interference ability is relatively weak. Weak, and the electromagnetic wave energy radiated from the GIS insulator is small, coupled with the large attenuation in space, the sensitivity is greatly reduced, and the application is also limited

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