External sensor for GIS partial discharge detection

Abstract

The invention discloses an external sensor for GIS (Gas Insulated Switchgear) partial discharge detection. The external sensor comprises an airfoil patch antenna used for receiving an electromagnetic wave signal generated by GIS partial discharge; the outside of the airfoil patch antenna is coated with a sensor shell used for being fixed on a GIS basin type insulator; the sensor shell is also used for encapsulating the airfoil patch antenna and shielding an external disturbance signal; a feed N-type coaxial connector for being connected with an external feed coaxial cable is arranged on the sensor shell; a first coaxial cable for connecting the airfoil patch antenna and the feed N-type coaxial connector is also arranged in the sensor shell. When the sensor is designed, the return loss and the frequency bandwidth of the sensor can be regulated and defined according to the shape, the size and other parameters of the airfoil patch antenna, so as to realize the correspondence between the frequency band of the antenna and a main frequency band of an electromagnetic wave signal leaked from the basin type insulator, therefore, the sensor is ensured to have wider detection bandwidth and higher sensitivity.

Description

technical field [0001] The invention relates to the technical field of electric equipment insulation state diagnosis, in particular to an external sensor used for GIS partial discharge detection. Background technique [0002] Gas Insulated Switchgear (GIS) has the advantages of small footprint and high operational reliability, and has gradually been widely used in substations. During the assembly and operation of GIS, there may be defects that affect the insulation performance, such as scratches on the center guide rod, and metal particles generated during the breaking process of the circuit breaker. GIS using high pressure SF 6 The gas is insulated, and the internal electric field is a slightly uneven field, and internal defects will cause local electric field enhancement, causing partial discharge or even insulation breakdown. [0003] Among them, the partial discharge is manifested as a current pulse with a very steep rising edge and a very narrow pulse width, which wil...

AI Technical Summary

Problems solved by technology

However, the receiving frequency band of the rectangular patch antenna is generally narrow, and the detection sensitivity is low; the horn antenna is too large and not easy to carry; although the structure of the dipole antenna is simple, it needs to choose a reasonable location during installation, requiring the site personnel to have a certain antenna foundation Knowledge

In addition, at present, the effective detection bandwidth of many antennas has not been reasonably designed, and cannot correspond to the main frequency band of the electromagnetic wave leaked by the pot insulator (600MHz~2GHz), so the detection sensitivity is not high

Images