CN-121978606-A - Verification method for GIS partial discharge medium window type ultrahigh frequency sensor

CN121978606ACN 121978606 ACN121978606 ACN 121978606ACN-121978606-A

Abstract

The invention discloses a method for checking a partial discharge medium window type ultrahigh frequency sensor aiming at a GIS, and relates to the field of checking of partial discharge ultrahigh frequency sensors. According to the method, a standard ultrahigh frequency sensor and an ultrahigh frequency sensor to be checked are arranged on a GIS defect simulation device, a network analyzer is used for injecting discharge signals, and the maximum installation height h max of the ultrahigh frequency sensor is calculated by measuring the signal amplitude and background noise of the sensor to be checked at a medium window flange, the diameter of a metal disc antenna and the diameter of a medium window of the ultrahigh frequency sensor to be checked and combining the waveguide cutoff theory and the medium transmission characteristic. The invention can check the GIS ultrahigh frequency sensor on site in the uninterrupted power supply state, effectively solves the problem of overlarge signal attenuation caused by improper installation depth of the sensor in the prior art, and ensures the accuracy and reliability of the checking result.

Inventors

WANG LUGA
WAN LI
YANG YONGZE
ZHANG XIAOSHAN
ZHU ZIXI

Assignees

中国矿业大学

Dates

Publication Date: 20260505
Application Date: 20260324

Claims (3)

1. The checking method for the GIS partial discharge medium window type ultrahigh frequency sensor is characterized by comprising the following steps of: Step 1, designing a GIS defect simulation device of a gas insulated switchgear, wherein the device comprises a GIS shell (1), a standard ultrahigh frequency sensor (6), an ultrahigh frequency sensor (7) to be checked, a network analyzer (8) and a coaxial cable (9); Step 2, connecting a first port of a network analyzer (8) with a standard ultrahigh frequency sensor (6) through a coaxial cable (9), and connecting a second port of the network analyzer (8) with the ultrahigh frequency sensor (7) to be verified through the coaxial cable (9); and 3, injecting a discharge signal into the standard ultrahigh frequency sensor (6) by using a network analyzer (8), receiving the signal by using the ultrahigh frequency sensor (7) to be checked, and establishing a maximum installation height model of the ultrahigh frequency sensor (7) to be checked based on the diameter of the metal disc antenna (5) and the diameter of the dielectric window hand hole of the ultrahigh frequency sensor (7) to be checked.
2. The method for checking the ultrahigh frequency sensor of the GIS partial discharge medium window type according to claim 1, wherein the standard ultrahigh frequency sensor (6) and the ultrahigh frequency sensor (7) to be checked in the step 1 are disc type sensors and are installed in the medium window.
3. The method for checking the partial discharge medium window type ultrahigh frequency sensor for the GIS according to claim 1, wherein the maximum installation height of the ultrahigh frequency sensor to be checked is as follows: ; Wherein D s is the diameter of a sensor metal disc antenna (5), D h is the diameter of a dielectric window hand hole, h w is the thickness of the dielectric window, U 0 is the voltage amplitude measured at the ultrahigh frequency sensor to be checked when h=0, U min is the bottom noise voltage amplitude measured at the ultrahigh frequency sensor to be checked when no partial discharge signal h=0, Is the relative dielectric constant of the window medium, The relative dielectric constant of the transformer oil; is used as a correction factor for the transmittance of the interface, ; The installation depth H of the ultrahigh frequency sensor (7) to be checked needs to be H < H max .

Description

Verification method for GIS partial discharge medium window type ultrahigh frequency sensor Technical Field The invention relates to the technical field of partial discharge ultrahigh frequency sensor verification, in particular to a method for verifying a GIS partial discharge medium window type ultrahigh frequency sensor. Background As a core switching device of an electric power system, a Gas Insulated Switchgear (GIS) has an insulation state directly related to the safe operation of the electric network. Partial discharge is a main cause of deterioration of insulation of high-voltage equipment and is also a precursor of insulation failure. The ultrahigh frequency detection technology has been widely applied to the on-line monitoring of partial discharge of GIS due to the advantages of high sensitivity, strong anti-interference performance and the like. However, in long-term operation, the performance of the uhf sensor may be degraded due to aging, corrosion, physical damage, and the like, resulting in a decrease in sensitivity. The mounting mode and the position of the ultrahigh frequency sensor can influence the signal receiving of the sensor. The partial discharge in the GIS can not be found in time to give out early warning and serious consequences are generated, so that the sensor is required to be checked regularly. Under actual operation conditions, the ultrahigh frequency sensor is mostly installed in a dielectric window of the GIS, and the installation depth of the ultrahigh frequency sensor can influence the verification result of the ultrahigh frequency sensor. If the installation depth of the ultrahigh frequency sensor is too shallow, the ultrahigh frequency signal attenuation is too large to cause missed detection, so that the verification of the ultrahigh frequency sensor is affected, and if the installation depth is too large, the insulation is affected. Disclosure of Invention The present invention will be described in detail by the following specific examples to fully explain the technical aspects and the intended effects of the present invention. The invention provides a verification method for a GIS partial discharge medium window type ultrahigh frequency sensor, which comprises the following steps: Step 1, designing a GIS defect simulation device of a gas insulated switchgear, wherein the device comprises a GIS shell, a standard ultrahigh frequency sensor, an ultrahigh frequency sensor to be checked, a network analyzer and a coaxial cable; Step 2, connecting a first port of the network analyzer with a standard ultrahigh frequency sensor through a coaxial cable, and connecting a second port of the network analyzer with the ultrahigh frequency sensor to be checked through the coaxial cable; And 3, injecting discharge signals into the standard ultrahigh frequency sensor by using a network analyzer, receiving signals by using the ultrahigh frequency sensor to be checked, and establishing a maximum installation height model of the ultrahigh frequency sensor to be checked based on the diameter of the metal disc antenna and the diameter of the dielectric window hand hole of the ultrahigh frequency sensor to be checked. Furthermore, the standard ultrahigh frequency sensor and the ultrahigh frequency sensor to be verified in the step 1 are disc sensors and are arranged in the dielectric window. Further, the maximum installation height of the ultrahigh frequency sensor to be checked is as follows: ; Wherein D s is the diameter of a metal disc antenna of the sensor, D h is the diameter of a hand hole of a dielectric window, h w is the thickness of the dielectric window, U 0 is the voltage amplitude measured at the ultrahigh frequency sensor to be checked when h=0, U min is the bottom noise voltage amplitude measured at the ultrahigh frequency sensor to be checked when no partial discharge signal h=0, Is the relative dielectric constant of the window medium,The relative dielectric constant of the transformer oil; is used as a correction factor for the transmittance of the interface, ; The installation depth H of the ultrahigh frequency sensor to be checked needs to be H < H max. Compared with the prior art, the invention has the following beneficial effects: The invention can check the GIS ultrahigh frequency sensor on site in the uninterrupted power supply state, effectively solves the problem of overlarge signal attenuation caused by improper installation height of the sensor in the prior art, and ensures the accuracy and reliability of the checking result. Drawings FIG. 1 is a flow chart of a verification method for a GIS partial discharge medium window type ultrahigh frequency sensor provided by the invention; FIG. 2 is a schematic diagram of a GIS dielectric window structure provided in the present invention; FIG. 3 is a schematic diagram of checking a GIS partial discharge ultrahigh frequency sensor provided by the invention; reference numerals in the drawings: The system comprises a 1-GIS