A 220KV current transformer bushing end screen signal pickup device

Abstract

The invention discloses a 220KV current transformer bushing end screen signal pickup device. The existing device has the problems of inconvenient installation, large signal attenuation and low detection efficiency. The invention comprises a high-frequency signal acquisition component and a low-frequency signal acquisition component which are threadedly connected. The high-frequency signal acquisition component comprises a high-frequency component housing, a horizontal baffle, a copper rod fixing block, a copper rod, and a high-frequency partial discharge sensor. The horizontal baffle and the copper rod fixing block isolate the copper rod from the high-frequency component housing. The low-frequency signal acquisition component comprises a low-frequency component housing, a cotter pin, a metal hose lead-out tube, a sensor mounting inner tube, a sensor mounting outer tube, and a low-frequency dielectric loss sensor. After the metal hose together with the high-frequency signal line and the low-frequency signal line are led out of the pickup device through the metal hose lead-out tube, a resin material is injected to seal the metal hose lead-out tube. The invention adopts an integrated sealing structure, has good shielding performance and anti-interference performance, is safe and reliable to use, and can effectively adapt to the on-site environment.

Description

Technical Field

[0001] The invention belongs to the technical field of power transmission, in particular to the technical field of high-voltage detection, and relates to a method for picking up a 220KV current transformer bushing end screen signal. Background Art

[0002] Current transformer bushing failure is one of the important reasons for power outages caused by power equipment failures, which seriously endangers the safe and reliable operation of the equipment. At present, the main way to detect the insulation status of the bushing is to conduct preventive tests, but the test cycle of preventive tests is long and it is difficult to timely discover potential failures of bushings in operation.

[0003] Casing partial discharge detection mainly collects signals through the casing end screen. At present, relevant personnel have developed a device for collecting signals from the casing end screen, which mainly collects current, phase and other signals from the casing end screen by changing the casing end screen grounding structure and extending the casing end screen grounding wire. The existing device has the defects of inconvenient installation, large signal attenuation, low detection efficiency and potential safety hazards. Summary of the invention

[0004] The purpose of the present invention is to provide a 220KV current transformer bushing end screen signal pickup device in view of the deficiencies in the prior art.

[0005] The invention comprises a high-frequency signal acquisition component and a low-frequency signal acquisition component which are threadedly connected.

[0006] The high-frequency signal acquisition component comprises a high-frequency component shell, a horizontal baffle, a copper rod fixing block, a copper rod, and a high-frequency partial discharge sensor.

[0007] The high-frequency component housing is a metal cylinder with two open ends, and the inner wall of the housing is in a step shape.

[0008] The horizontal baffle is a circular non-metallic material plate, which is fixedly connected to one end of the high-frequency component housing, and a copper rod through-hole is opened in the center of the horizontal baffle.

[0009] The copper rod fixing block is a plastic stepped cylinder with a copper rod through hole axially opened in the center. The copper rod fixing block is arranged on a horizontal baffle, and the stepped shape of its outer wall matches the stepped shape of the inner wall of the high-frequency component housing.

[0010] The copper rod is a stepped cylinder with a T-shaped longitudinal section, an upper portion being a mounting platform and a lower portion being a copper rod body; the mounting platform is arranged on a copper rod fixing block, and the copper rod and the copper rod fixing block are fixedly connected by screws; the copper rod body passes through the copper rod through hole and the copper rod is perforated, and then extends out of the high-frequency component housing.

[0011] The high-frequency partial discharge sensor is a ceramic ring wound with a coil, which is sleeved outside the installation platform part of the copper rod.

[0012] The low-frequency signal acquisition component comprises a low-frequency component housing, a cotter pin, a metal hose lead-out tube, a sensor installation inner tube, a sensor installation outer tube, and a low-frequency dielectric loss sensor.

[0013] The low-frequency component shell is a metal cylinder with one end open and the other end closed. The open end is threadedly connected to one end of the high-frequency component shell, and the closed end is provided with a cotter pin. The side wall is provided with a metal hose lead-out tube, and the metal hose lead-out tube is connected to the inner cavity of the low-frequency component shell.

[0014] The sensor installation inner cylinder is coaxially arranged with the sensor installation outer cylinder, the sensor installation inner cylinder is arranged inside the sensor installation outer cylinder, the upper end of the sensor installation inner cylinder is fixedly connected with the upper end of the sensor installation outer cylinder through an annular upper cover plate, the lower end of the sensor installation inner cylinder is fixedly connected with the lower end of the sensor installation outer cylinder through an annular lower cover plate, and the upper cover plate is provided with a low-frequency signal line lead-out hole.

[0015] The low-frequency dielectric loss sensor is a ceramic ring wound with a coil, which is arranged in a circular cylindrical space surrounded by a sensor mounting inner cylinder, a sensor mounting outer cylinder, an upper cover plate and a lower cover plate;

[0016] One end of the low-frequency signal line is fixed on the low-frequency dielectric loss sensor, and the other end passes through the low-frequency signal line lead-out hole and is introduced into the metal hose; one end of the high-frequency signal line is fixed on the high-frequency partial discharge sensor, and the other end passes through the gap between the sensor mounting outer cylinder and the low-frequency component shell and is introduced into the metal hose.

[0017] The horizontal baffle is arranged at one end of the high-frequency component housing, and the copper rod fixing block, the copper rod and the high-frequency partial discharge sensor are arranged in the high-frequency component housing.

[0018] Furthermore, an annular groove is formed on the inner wall of the high-frequency component housing near the bottom, and an annular protrusion is formed along the side of the horizontal baffle; the annular protrusion is located in the annular groove, and the horizontal baffle is fixedly connected to the high-frequency component housing.

[0019] Furthermore, the horizontal baffle and the copper rod fixing block isolate the copper rod from the high-frequency component housing.

[0020] Furthermore, a sealing ring is provided at the connection between the high-frequency component housing and the low-frequency component housing.

[0021] Furthermore, the sensor installation inner cylinder, sensor installation outer cylinder, upper cover plate and lower cover plate are all made of metal materials, enclosing a circular cylindrical low-frequency dielectric loss sensor installation space.

[0022] Furthermore, a blind hole for welding a copper rod grounding wire is opened at the center of the top surface of the copper rod installation platform, and a blind hole for welding a grounding wire is opened on the upper inner wall of the low-frequency component shell; one end of the copper rod grounding wire is welded in the blind hole for welding a copper rod grounding wire, and after passing through the sensor installation inner tube, the other end is welded in the blind hole for welding a grounding wire; one end of the sensor installation tube grounding wire is connected to the upper cover plate, and the other end is also welded in the blind hole for welding a grounding wire.

[0023] Furthermore, the metal hose together with the high-frequency signal line and the low-frequency signal line are led out of the pickup device through the metal hose lead-out tube; after the metal hose extends out of the metal hose lead-out tube, resin material is injected through the metal hose lead-out tube to seal the metal hose lead-out tube.

[0024] The present invention adopts an integrated sealing structure with good shielding and anti-interference performance. Each part can be reliably contacted and can be safely and effectively grounded. It is oil-resistant, solvent-resistant, and high and low temperature-resistant. It is safe and reliable to use, can be used for a long time, and can effectively adapt to the field environment. The present invention avoids the defects of the prior art. The entire device forms the shortest grounding path without changing the original grounding method. It is easy to install without changing the grounding structure of the end screen of the casing, and there is no need to extend the grounding wire of the end screen of the casing. At the same time, it can effectively obtain signals through low-frequency dielectric loss sensors and high-frequency partial discharge sensors, and the signal attenuation is small, the detection efficiency is greatly improved, and there are no defects such as safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention. DETAILED DESCRIPTION

[0026] like Figure 1 As shown, a 220KV current transformer bushing end screen signal pickup device includes a threaded high-frequency signal acquisition component I and a low-frequency signal acquisition component II.

[0027] The high-frequency signal acquisition component I includes a high-frequency component housing 1, a horizontal baffle 2, a copper rod fixing block 3, a copper rod 4, and a high-frequency partial discharge sensor 5. The horizontal baffle 2 is arranged at one end of the high-frequency component housing 1, and the copper rod fixing block 3, the copper rod 4, and the high-frequency partial discharge sensor 5 are arranged in the high-frequency component housing 1.

[0028] The high-frequency component housing 1 is a metal cylinder with two ends open, an annular groove is formed on the inner wall near the bottom, and the inner wall of the housing is stepped.

[0029] The horizontal baffle 2 is a circular non-metallic plate with an annular protrusion along the side, which is inserted into the annular groove. The horizontal baffle 2 is fixedly connected to one end of the high-frequency component housing 1, and a copper rod through-hole is opened in the center of the horizontal baffle 2.

[0030] The copper rod fixing block 3 is a plastic stepped cylinder with a copper rod through hole axially opened in the center. The copper rod fixing block 3 is arranged on the horizontal baffle 2 , and the stepped shape of its outer wall matches the stepped shape of the inner wall of the high-frequency component housing 1 .

[0031] The copper rod 4 is a stepped cylinder with a T-shaped longitudinal section, the upper part is the mounting platform and the lower part is the copper rod body. The mounting platform is set on the copper rod fixing block 3, and the copper rod 4 is fixedly connected to the copper rod fixing block 3 by screws. A blind hole 4-1 for welding the copper rod grounding wire is opened in the center of the top surface of the mounting platform. After the copper rod body passes through the copper rod through hole and the copper rod is perforated, it extends out of the high-frequency component housing 1. The horizontal baffle 2 and the copper rod fixing block 3 isolate the copper rod 4 from the high-frequency component housing 1. During operation, the copper rod 4 is connected to the end screen lead-out end of the bushing of the current transformer through a metal strip.

[0032] The high-frequency partial discharge sensor 5 is a ceramic ring wound with a coil, and is sleeved outside the mounting platform portion of the copper rod 4 .

[0033] The low-frequency signal acquisition component II includes a low-frequency component housing 6, a cotter pin 8, a metal hose lead-out tube 9, a sensor installation inner tube 10, a sensor installation outer tube 11, and a low-frequency dielectric loss sensor 15.

[0034] The low-frequency component housing 6 is a metal cylinder with one end open and the other end closed. The open end is threadedly connected to one end of the high-frequency component housing 1. A sealing ring 7 is provided at the connection to play a role of waterproof, dustproof and shockproof. A cotter pin 8 is provided at the closed end of the low-frequency component housing 6 to connect with the bushing end screen grounding cover of the current transformer. A metal hose lead-out tube 9 is provided on the side wall of the low-frequency component housing 6, and the metal hose lead-out tube 9 is connected to the inner cavity of the low-frequency component housing 6.

[0035] The sensor installation inner cylinder 10 is coaxially arranged with the sensor installation outer cylinder 11, and the sensor installation inner cylinder 10 is arranged inside the sensor installation outer cylinder 11. The upper end of the sensor installation inner cylinder 10 is fixedly connected with the upper end of the sensor installation outer cylinder 11 through a circular upper cover plate 12, and the lower end of the sensor installation inner cylinder 10 is fixedly connected with the lower end of the sensor installation outer cylinder 11 through a circular lower cover plate 13. The upper cover plate 12 is provided with a low-frequency signal line lead-out hole 14. The sensor installation inner cylinder 10, the sensor installation outer cylinder 11, the upper cover plate 12, and the lower cover plate 13 are all made of metal materials.

[0036] The low-frequency dielectric loss sensor 15 is a ceramic ring wound with a coil, and is disposed in a circular cylindrical space enclosed by the sensor mounting inner cylinder 10 , the sensor mounting outer cylinder 11 , the upper cover plate 12 and the lower cover plate 13 .

[0037] A ground wire welding blind hole 6-1 is opened on the upper inner wall of the low-frequency component housing 6. One end of the copper rod ground wire is welded in the copper rod ground wire welding blind hole 4-1, and the other end is welded in the ground wire welding blind hole 6-1 after passing through the sensor installation inner cylinder 10. One end of the sensor installation cylinder ground wire is connected to the upper cover plate 12, and the other end is also welded in the ground wire welding blind hole 6-1.

[0038] One end of the low-frequency signal line is fixed on the low-frequency dielectric loss sensor, and the other end passes through the low-frequency signal line lead-out hole and is introduced into the metal hose 16. The low-frequency signal line is used to transmit the low-frequency dielectric loss signal detected by the low-frequency dielectric loss sensor to the relative dielectric loss tester for analysis.

[0039] One end of the high-frequency signal line is fixed to the high-frequency partial discharge sensor, and the other end passes through the gap between the sensor mounting outer cylinder 11 and the low-frequency component housing 6 and is introduced into the metal hose 16. The high-frequency signal line is used to transmit the high-frequency partial discharge signal detected by the high-frequency partial discharge sensor to the high-frequency partial discharge detector for analysis.

[0040] The metal hose 16, together with the high-frequency signal line and the low-frequency signal line, is led out of the pickup device through the metal hose lead-out tube 9. After the metal hose 16 extends out of the metal hose lead-out tube 9, resin material is injected through the metal hose lead-out tube 9 to seal the metal hose lead-out tube 9.

[0041] When in use, the copper rod in the device is reliably connected to the lead-out end of the current transformer bushing end screen through a metal strip and fixed with a nut. The split pin is reliably contacted with the bushing end screen grounding cover of the current transformer and fixed with a nut. The lead-out end of the current transformer bushing end screen and the bushing end screen grounding cover of the current transformer form a reliable grounding loop, which can form the shortest grounding path without changing the original grounding method, effectively avoiding changing the grounding structure of the bushing end screen, and there is no need to extend the bushing end screen grounding wire. The signal is detected by the low-frequency dielectric loss sensor and high-frequency partial discharge sensor that are inserted into the grounding loop, and the signal is transmitted to the relative dielectric loss tester and high-frequency partial discharge detector through the signal line for analysis. The signal attenuation in this process is small, and the detection efficiency is greatly improved.

Claims

1. A 220KV current transformer bushing end screen signal pickup device, comprising a threaded high-frequency signal acquisition component and a low-frequency signal acquisition component; characterized in that: The high-frequency signal acquisition component comprises a high-frequency component housing (1), a horizontal baffle (2), a copper rod fixing block (3), a copper rod (4), and a high-frequency partial discharge sensor (5); the horizontal baffle (2) is arranged at one end of the high-frequency component housing (1), and the copper rod fixing block (3), the copper rod (4), and the high-frequency partial discharge sensor (5) are arranged inside the high-frequency component housing (1); The high-frequency component housing (1) is a metal cylinder with two open ends, and the inner wall of the housing is stepped; The horizontal baffle (2) is a circular non-metallic material plate, the horizontal baffle (2) is fixedly connected to one end of the high-frequency component housing (1), and a copper rod through hole is opened in the center of the horizontal baffle (2); An annular groove is formed on the inner wall of the high-frequency component housing (1) near the bottom, and an annular protrusion is formed along the side of the horizontal baffle (2); the annular protrusion is located in the annular groove, and the horizontal baffle (2) is fixedly connected to the high-frequency component housing (1); The copper rod fixing block (3) is a plastic stepped cylinder with a copper rod through hole axially opened in the center. The copper rod fixing block (3) is arranged on the horizontal baffle (2), and the stepped shape of its outer wall matches the stepped shape of the inner wall of the high-frequency component housing (1). The copper rod (4) is a stepped cylinder with a T-shaped longitudinal section, the upper part of which is a mounting platform and the lower part of which is a copper rod body; the mounting platform is arranged on the copper rod fixing block (3), and the copper rod (4) and the copper rod fixing block (3) are fixedly connected by screws; the copper rod body passes through the copper rod through hole and the copper rod is perforated, and then extends out of the high-frequency component housing (1); the horizontal baffle (2) and the copper rod fixing block (3) isolate the copper rod (4) from the high-frequency component housing (1); The high-frequency partial discharge sensor (5) is a ceramic ring wound with a coil, and the high-frequency partial discharge sensor (5) is sleeved outside the mounting platform portion of the copper rod (4); The low-frequency signal acquisition component comprises a low-frequency component housing (6), a split pin (8), a metal hose lead-out tube (9), a sensor mounting inner tube (10), a sensor mounting outer tube (11), and a low-frequency dielectric loss sensor (15); The low-frequency component housing (6) is a metal cylinder with one end open and the other end closed, the open end being threadedly connected to one end of the high-frequency component housing (1), the closed end being provided with a cotter pin (8), the side wall being provided with a metal hose lead-out tube (9), the metal hose lead-out tube (9) being in communication with the inner cavity of the low-frequency component housing (6); a sealing ring (7) is provided at the connection between the high-frequency component housing (1) and the low-frequency component housing (6); A copper rod grounding wire welding blind hole (4-1) is opened at the center of the top surface of the installation platform of the copper rod (4), and a grounding wire welding blind hole (6-1) is opened at the upper inner wall of the low-frequency component shell (6); one end of the copper rod grounding wire is welded in the copper rod grounding wire welding blind hole (4-1), and after passing through the sensor installation inner tube (10), the other end is welded in the grounding wire welding blind hole (6-1); one end of the sensor installation tube grounding wire is connected to the upper cover plate (12), and the other end is also welded in the grounding wire welding blind hole (6-1); The sensor installation inner cylinder (10) and the sensor installation outer cylinder (11) are coaxially arranged, the sensor installation inner cylinder (10) is arranged inside the sensor installation outer cylinder (11), the upper end of the sensor installation inner cylinder (10) and the upper end of the sensor installation outer cylinder (11) are fixedly connected via an annular upper cover plate (12), the lower end of the sensor installation inner cylinder (10) and the lower end of the sensor installation outer cylinder (11) are fixedly connected via an annular lower cover plate (13), and the upper cover plate (12) is provided with a low-frequency signal line lead-out hole (14); The sensor installation inner cylinder (10), the sensor installation outer cylinder (11), the upper cover plate (12), and the lower cover plate (13) are all made of metal materials, and enclose a circular cylindrical low-frequency dielectric loss sensor installation space; the low-frequency dielectric loss sensor (15) is a ceramic ring wound with a coil, and is arranged in the low-frequency dielectric loss sensor installation space; One end of the low-frequency signal line is fixed to the low-frequency dielectric loss sensor, and the other end passes through the low-frequency signal line lead-out hole and is introduced into the metal hose (16); one end of the high-frequency signal line is fixed to the high-frequency partial discharge sensor, and the other end passes through the gap between the sensor mounting outer cylinder (11) and the low-frequency component housing (6) and is introduced into the metal hose (16); The metal hose (16) together with the high-frequency signal line and the low-frequency signal line are led out of the pickup device through the metal hose lead-out tube (9); after the metal hose (16) extends out of the metal hose lead-out tube (9), resin material is injected through the metal hose lead-out tube (9) to seal the metal hose lead-out tube (9); When the device is used, the copper rod (4) is connected to the lead-out end of the bushing end screen of the current transformer through a metal strip and fixed with a nut; the split pin (8) contacts the grounding cover of the bushing end screen of the current transformer and is fixed with a nut.

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