A built-in ultrahigh frequency partial discharge sensor

Abstract

The utility model belongs to the technical field of electric power equipment, concretely relates to a built-in ultrahigh frequency partial discharge sensor. The sensor includes N type joint, installation apron, insulation connecting piece, compression ring and central induction electrode, central induction electrode is used for obtaining partial discharge analog quantity, central induction electrode is integral type structure, insulation connecting piece installs in the downside of installation apron, and compression ring and insulation connecting piece adopt nested mode connection, compression ring is used for limiting the deformation of insulation connecting piece, and the centre of insulation connecting piece is prefabricated with through -hole, and the top of central induction electrode is connected with N type joint after passing through the through -hole, central induction electrode is screwed in insulation connecting piece. The problem of poor sensitivity of the existing sensor is solved.

Description

Technical Field

[0001] This utility model belongs to the field of power equipment technology, specifically relating to a built-in ultra-high frequency partial discharge sensor. Background Technology

[0002] Gas-insulated metal-enclosed switchgear (GIS), as a key piece of equipment in power transmission and transformation, is gradually replacing open-type switchgear and is widely used in power systems due to its advantages such as compact structure, safe and reliable operation, long maintenance cycle, and immunity to external environmental influences. Various insulation defects generated during the manufacturing, transportation, installation, and operation of GIS equipment can be characterized by partial discharge signals of varying degrees and forms, and partial discharge phenomena can exacerbate insulation degradation. Partial discharge detection, as the most important part of insulation condition monitoring, has significant guiding value for judging the insulation condition of GIS. The more sensitive the detection of minute partial discharges, the more effectively early insulation defects can be discovered, thereby avoiding insulation breakdown accidents. Therefore, accurate and reliable partial discharge sensors are crucial for preventing failures.

[0003] Built-in partial discharge sensors are installed inside GIS. They have advantages such as good anti-down-disturbance performance and high sensitivity, and are being used more and more widely in GIS.

[0004] A search revealed CN 210982662 U, which discloses a built-in ultra-high frequency partial discharge signal detection sensor. This sensor utilizes a threaded connection between a metal electrode and a solid conductor, combined with a cast-in insulating plate, to ensure that replacing the metal electrode does not affect the seal between the insulating plate and the solid conductor on the mounting hole. Wireless communication and an epoxy resin insulating plate enhance sealing and anti-interference performance. A brass connecting rod connects to the metal electrode through the center hole of the mounting cover. The sensing probe connects to the other end of the metal electrode to transmit the partial discharge signal collected by the sensing probe from within the GIS (Gas Insulated Geological Components). The probe is spin-type and connected to the central conductor via a threaded fastener, making installation simple and providing strong anti-interference capabilities. Furthermore, by replacing the electrode probe, it can provide the most accurate built-in partial discharge sensor for GIS products of different voltage levels. The sensor uses a split probe, with the probe, metal electrode, and brass connecting rod all connected by threads. While this design provides some flexibility, subsequent research revealed that the split structure and different transmission media along the signal transmission path (probe-metal electrode-brass connecting rod) cause significant signal attenuation during transmission, reducing the sensor's sensitivity. Utility Model Content

[0005] The purpose of this invention is to provide a built-in ultra-high frequency partial discharge sensor, which solves the problem of poor sensitivity of existing sensors.

[0006] This utility model is achieved through the following technical solution: This utility model discloses a built-in ultra-high frequency partial discharge sensor, including an N-type connector, a mounting cover plate, an insulating connector, a pressure ring, and a central sensing electrode; the central sensing electrode is used to acquire analog partial discharge quantities. The central sensing electrode is a one-piece structure; The insulating connector is installed on the underside of the mounting cover plate, and the pressure ring is nested with the insulating connector; the pressure ring is used to limit the deformation of the insulating connector. The insulating connector has a pre-drilled through hole in the center, and the top of the central sensing electrode passes through the through hole and connects to the N-type connector. The central sensing electrode is threaded into an insulating connector.

[0007] Furthermore, a double axial sealing groove is provided at the contact point between the central sensing electrode and the insulating connector.

[0008] Furthermore, the mounting cover and the insulating connector have a flat sealing groove on their mating surfaces.

[0009] Furthermore, the pressure ring is made of metal.

[0010] Furthermore, the central sensing electrode is an integrally formed connecting rod, metal electrode and sensing probe connected sequentially from top to bottom; the bottom of the sensing probe is curved.

[0011] Furthermore, the top of the connecting rod has a pre-drilled threaded hole, and the N-type connector is threaded into the threaded hole.

[0012] Furthermore, the sensing probe is an omnidirectional antenna.

[0013] Furthermore, the cover plate, pressure ring, and insulating connector are fastened together with bolts.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: This utility model discloses a built-in ultra-high frequency partial discharge sensor. The sensor structure is simplified by having the upper part of the central sensing electrode pass through the central hole of the insulating connector, making the sensor installation process more convenient and avoiding installation errors caused by connecting multiple components, thus improving installation reliability. The integrated design of the central sensing electrode avoids signal transmission attenuation problems caused by split structures, improving the effectiveness and stability of signal transmission and ensuring that the sensor can accurately detect minute partial discharge signals. The assembly process is streamlined by reducing the connection steps of components such as probes, metal electrodes, and brass connecting rods. The nested fit between the pressure ring and the insulating connector, along with the double axial sealing groove design between the central sensing electrode and the insulating connector, forms a complete sealing structure, effectively preventing the influence of the external environment on the sensor and improving its operational reliability. The use of threaded connections eliminates the need for additional connectors, reducing the number of parts, lowering production costs, and simplifying maintenance.

[0015] Furthermore, the central sensing electrode is an integrally connected rod, metal electrode, and sensing probe connected sequentially from top to bottom; the bottom of the sensing probe is optimized into an arc-shaped structure, which can significantly increase the signal acquisition gain and improve the sensitivity of the sensor compared to the traditional planar structure, ensuring the effective acquisition of partial discharge signals. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a built-in ultra-high frequency partial discharge sensor disclosed in this utility model; 1. N-type connector; 2. Mounting cover plate; 3. Fastening nut; 4. Insulating connector; 5. Pressure ring; 6. Center sensing electrode; 7. Screw; Figure 2 This is a schematic diagram of the structure of the central sensing electrode; Figure 3 The figure shows the experimental test results of a built-in ultra-high frequency partial discharge sensor of this utility model. Figure 4 The figure shows the experimental test results of a built-in ultra-high frequency partial discharge sensor in the prior art; Figure 5 for Figure 1 A cross-sectional schematic diagram. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit it; that is, the described embodiments are only a part of, and not all, of the embodiments of this utility model.

[0018] The components described and illustrated in the accompanying drawings and embodiments of this utility model can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of this utility model provided in the following drawings is not intended to limit the scope of the claimed utility model, but merely to illustrate one selected embodiment of the utility model. All other embodiments obtained by those skilled in the art based on the accompanying drawings and embodiments of this utility model without inventive effort are within the protection scope of this utility model.

[0019] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, element, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to the process, element, method, article, or apparatus.

[0020] The following is an explanation of terms related to this utility model: Partial discharge: A discharge that occurs only in a localized area of ​​the insulation of electrical equipment and between conductors to which voltage has not yet been applied.

[0021] Ultra-high frequency (UHF): Radio waves with a wavelength range of 1m to 0.1m and a frequency range of 300 to 3000MHz.

[0022] To address the issue of low sensor sensitivity, various combinations of sensor components were tested. It was ultimately confirmed that the low sensitivity was mainly caused by significant signal attenuation during sensor transmission. Therefore, based on the cause of the problem, innovative designs were made for the components and their connection structures belonging to the central electrode of the sensor.

[0023] First, the structural form of each component was optimized. It was found that the sensitivity was improved after the structural form was modified, but the improvement was not significant. Subsequently, the connection structure between the components was optimized. The threaded connection structure between the components was innovatively eliminated and replaced with an integrated structure. After testing, the sensitivity was significantly improved.

[0024] After innovation and optimization, it was confirmed that the sensor adopts an integrated central connection structure. Based on research data and electromagnetic signal transmission principle research, the overall structural form of the central sensing electrode 6 was redesigned to further ensure the effectiveness of the sensor's signal transmission.

[0025] In the sensor design process, in addition to adopting traditional R&D models and tools, CST simulation was used to comprehensively simulate the actual operating conditions and test conditions of the sensor.

[0026] The features and performance of this utility model will be further described in detail below with reference to the embodiments.

[0027] like Figure 1 As shown, this utility model discloses a built-in ultra-high frequency partial discharge sensor, including: an N-type connector 1, a mounting cover plate 2, a fastening nut 3, an insulating connector 4, a pressure ring 5, and a central sensing electrode 6.

[0028] The pressure ring 5 and the insulating connector 4 are nested together, and the insulating connector 4 is bolted to the mounting cover plate 2. For example... Figure 5 As shown, during connection, the pressure ring 5 is nested on the insulating connector 4, and the screw 7 passes through the pressure ring 5 and the insulating connector 4 to connect to the mounting cover plate 2.

[0029] The pressure ring 5 is made of metal. In order to facilitate the bolt fixing between the insulating connector 4 and the mounting cover plate 2, it can effectively limit the deformation of the insulating connector 4, increase the installation tightening torque, and improve the installation reliability.

[0030] The stud structure on the upper part of the central sensing electrode 6 passes through the central hole of the insulating connector 4 and is fixed to the insulating connector 4 by the fastening nut 3. Figure 5 As shown, during connection, the upper rod-shaped structure of the central sensing electrode 6 passes through the central hole of the insulating connector 4, while the lower end cannot pass through. The part that passes through has a threaded structure. The fastening nut 3 is connected by screwing the rod-shaped threaded structure of the part through which the central sensing electrode 6 passes, thereby locking the central sensing electrode 6 and the insulating connector 4. The top of the central sensing electrode 6 is designed with a threaded hole, and the N-type connector 1 is threaded into the threaded hole to transmit the relevant signals it collects.

[0031] The central sensing electrode 6 is designed with a double axial sealing groove at the contact point with the insulating connector 4, and the mounting cover plate 2 is designed with a planar sealing groove at the contact surface with the insulating connector 4. An O-ring is installed in the sealing groove. These two sealing structures can effectively ensure the gas sealing performance of the sensor.

[0032] The central sensing electrode 6 is designed as a single unit, made entirely of metal; such as Figure 2 a represents the structure of the central sensing electrode 6 designed in this utility model, compared to, as shown in... Figure 2 As shown in b, the existing split-type center sensing electrode structure can reduce signal transmission attenuation, effectively improve signal transmission efficiency, and reduce signal transmission attenuation caused by threaded connections and the need for signals to pass through different media.

[0033] The central sensing electrode 6 is integrally manufactured from the connecting rod, metal electrode, and sensing probe, reducing the corresponding installation steps and improving installation efficiency; at the same time, it eliminates the sensor quality risk caused by assembly problems between central components.

[0034] like Figure 2As shown, compared to the planar structure of previous probes, the bottom of the sensing probe is designed with an arc surface. Studies on electromagnetic signals have shown that the sensing probe is an omnidirectional antenna. The curvature of the bottom of the omnidirectional antenna affects the beam direction and signal gain of the acquired signal. The larger the curvature of the bottom, the smaller the beam direction and the greater the signal gain of the acquired signal.

[0035] Through repeated research, it has been found that the arc-shaped structure of the sensing probe of the central sensing electrode 6 of this invention, compared with the planar structure, can greatly improve the signal gain of the acquired signal and enhance the sensitivity of the sensor while meeting the required beam pointing.

[0036] Among them, the sensitivity (effective height) of the built-in ultra-high frequency partial discharge sensor of this utility model was tested according to the State Grid enterprise standard Q / GDW 11311-2014. The test sensitivity (effective height) results are compared with, for example... Figure 3 As shown, the sensitivity is 9.304.

[0037] The sensors with previous central electrode structures were experimentally tested according to relevant standards, and the sensitivity results were compared to those of other sensors. Figure 4 As shown, the sensitivity is 7.042.

[0038] Experimental results show that the structural design of the central sensing electrode 6 of this invention significantly improves the overall sensitivity performance of the sensor compared to previous designs.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A built-in ultra-high frequency partial discharge sensor, characterized in that, It includes an N-type connector (1), a mounting cover plate (2), an insulating connector (4), a pressure ring (5), and a central sensing electrode (6); the central sensing electrode (6) is used to acquire partial discharge simulation quantities; The central sensing electrode (6) is an integral structure; The insulating connector (4) is installed on the underside of the mounting cover plate (2), and the pressure ring (5) is connected to the insulating connector (4) in a nested manner; the pressure ring (5) is used to limit the deformation of the insulating connector (4); The insulating connector (4) has a pre-drilled through hole in the center, and the top of the central sensing electrode (6) passes through the through hole and connects to the N-type connector (1); The central sensing electrode (6) is threaded into the insulating connector (4).

2. The built-in ultra-high frequency partial discharge sensor according to claim 1, characterized in that, The central sensing electrode (6) and the insulating connector (4) are fitted with a double axial sealing groove.

3. The built-in ultra-high frequency partial discharge sensor according to claim 1, characterized in that, The mounting cover (2) and the insulating connector (4) have a flat sealing groove on their mating surfaces.

4. The built-in ultra-high frequency partial discharge sensor according to claim 1, characterized in that, The pressure ring (5) is made of metal.

5. The built-in ultra-high frequency partial discharge sensor according to claim 1, characterized in that, The central sensing electrode (6) is an integral connecting rod, metal electrode and sensing probe connected from top to bottom; the bottom of the sensing probe is an arc surface.

6. The built-in ultra-high frequency partial discharge sensor according to claim 5, characterized in that, The top of the connecting rod has a pre-drilled threaded hole, and the N-type connector (1) is threaded into the threaded hole.

7. A built-in ultra-high frequency partial discharge sensor according to claim 5, characterized in that, The sensing probe is an omnidirectional antenna.

8. The built-in ultra-high frequency partial discharge sensor according to claim 1, characterized in that, The cover plate (2), pressure ring (5), and insulating connector (4) are fastened together by bolts.

Images