CN107677916B - High-voltage bushing end shield grounding shield and high-voltage bushing end shield - Google Patents

Abstract

The invention relates to a high-voltage bushing end screen grounding protective cover and a high-voltage bushing end screen, which comprise a grounding protective cover inner cover connected with a bushing end screen seat, a grounding protective cover outer cover connected with the grounding protective cover inner cover and an end screen lead extension rod connected with an end screen lead, wherein the end screen lead extension rod penetrates through the grounding protective cover inner cover to be connected with the grounding protective cover outer cover, a measuring coil is arranged between the inner wall of the grounding protective cover inner cover and the end screen lead extension rod, a measuring wire plug is arranged along the outer wall of the grounding protective cover inner cover, an output terminal of the measuring coil is connected with one end of a signal extraction wire, and the other end of the signal extraction wire is connected with the measuring wire plug. The invention not only realizes the measurement of leakage current, but also avoids the end screen of the high-voltage bushing from being exposed outside during routine state maintenance test.

Description

High-voltage bushing end shield grounding shield and high-voltage bushing end shield

technical field

The invention relates to the technical field of high-voltage equipment insulation, in particular to a high-voltage bushing end shield grounding shield and a high-voltage bushing end shield.

Background technique

The main insulation of the high-voltage bushing is mainly the capacitor core, which is formed by winding multi-layer capacitor plates according to certain design parameters, and the last screen is the outermost layer of capacitor plates, also known as the ground plate. In the actual live running of the casing, in order to achieve the uniform distribution of the electric field inside the casing, the terminal screen must be equipotentially connected to the ground, that is, it needs to be reliably grounded; while the casing is subjected to routine condition maintenance tests or preventive tests, the casing The end screen of the tube is the only measuring tap of the casing, and the end screen needs to be disconnected and grounded to conduct various tests.

In recent years, casing accidents caused by the quality of casing production process and operation and installation have occurred frequently. According to incomplete statistics, more than 50% of the accidents are caused by poor grounding of the end screen, which seriously affects the safety and stability of the power grid and the reliability of power supply. huge economic losses and adverse effects. Therefore, on the one hand, it is urgent to realize the condition monitoring, evaluation and insulation diagnosis of the bushing; Purpose.

At present, the grounding of the end shield of the bushing is mainly realized by the end shield grounding insulating cover. For example, a Chinese utility model patent (204925178U) discloses a high-voltage bushing secondary end shield lead-out device, as shown in Figure 1, the lead-out device includes: an insulating cover 1 , O-shaped gasket 2, lead-out terminal 3, T-shaped gasket 4; wherein, the insulating cover 1 includes a micro-capacitor and a metal cover; the top of the micro-capacitor is connected to the metal cover, and the bottom of the micro-capacitor is connected to the copper conductive rod; The terminal 3 includes a copper conducting rod, a round tube-shaped porcelain insulating medium, and a metal fixing part; the copper conducting rod passes through the center of the round tube-shaped porcelain insulating medium, and its two ends are respectively connected to the sub-screen lead and the microcapacitor; the metal fixing part Sleeve outside the cylindrical porcelain insulating medium; T-shaped gasket 4 is sealed on the lead-out terminal 3 and the lower edge of the metal fixing part; O-shaped gasket 2 is sealed on the lead-out terminal 3 and the upper edge of the metal fixing part . Although the above can lead out the potential of the second and last screens of the bushing and ensure good insulation of the terminals of the second and last screens, the following problems still exist: the existing grounding insulation cover of the last screen directly grounds the leakage current flowing out of the lead of the last screen, which cannot achieve leakage. measurement of current; in addition, after the existing end-screen grounding insulating cover is installed, during the live operation of the bushing, it is impossible to visually observe or judge whether the grounding is good; in addition, routine condition maintenance test or preventive During the performance test (offline test), it is necessary to completely disassemble the grounding insulating cover of the existing terminal screen, so that the entire terminal screen is completely exposed to the air, which not only easily makes the terminal screen damp but also affects the validity of the test data. At the same time, repeated disassembly and assembly of the grounding insulation cover of the end screen will cause problems such as insufficient crimping or virtual connection of the end screen protective cover due to factors such as human error or wear of the device itself, resulting in unreliable grounding of the end screen.

SUMMARY OF THE INVENTION

Therefore, the technical problem to be solved by the present invention is to overcome the problem of defects in products in the prior art, so as to provide a high-voltage bushing end screen grounding shield and a high-voltage bushing end shield that can ensure the appearance of the product even for plastics with high viscosity. Screen.

In order to solve the above technical problems, a high-voltage bushing end shield grounding shield of the present invention is installed on the high-voltage casing end shield, and the high-voltage casing end shield includes a casing end shield seat and a casing located at the casing end shield. The end shield lead on the base, the ground shield includes a ground shield inner shield connected with the casing end shield base, a ground shield outer shield connected with the ground shield inner shield, and the end shield lead Connected end screen lead extension rod, wherein the end screen lead extension rod passes through the grounding shield inner cover and is connected with the grounding shield outer cover, and the inner wall of the grounding shield inner cover is extended with the end screen lead A measurement coil is installed between the rods, a measurement wire plug connector is installed along the outer wall of the inner cover of the grounding shield, the output terminal of the measurement coil is connected to one end of the signal extraction wire, and the other end of the signal extraction wire is connected to the Connect the measuring line with the plug connector.

In an embodiment of the present invention, a light-emitting device is also installed along the outer wall of the inner cover of the grounding shield, and the light-emitting device is connected to the signal extraction line.

In an embodiment of the present invention, a spring member is provided in the middle of the end-screen lead extension rod.

In one embodiment of the present invention, an insulating sleeve is sleeved on the outside of the extension rod of the end-shield lead, and the insulating sleeve is installed on the end-shield between the contact end of the end-shield lead and the spring member on the lead extension rod.

In an embodiment of the present invention, a shielding lining is provided on the inner wall of the inner cover of the grounding shield.

In an embodiment of the present invention, an insulating ferrule is provided between the measuring coil and the shielding liner, and the measuring coil is located between the insulating ferrule and the end-screen lead extension rod.

In an embodiment of the present invention, a first butt sealing groove and a butt wire port are provided at the butting portion of the grounding shield outer cover and the grounding shield inner cover.

In an embodiment of the present invention, a second butting sealing groove and a connecting wire port are provided at the butting position of the inner cover of the grounding shield and the end shield of the casing.

The invention also discloses a high-voltage bushing end shield, which includes a casing end shield seat, an end shield lead located on the casing end shield seat, and the above-mentioned high-voltage casing end shield grounding shield.

In an embodiment of the present invention, the outer wall of the end screen lead is sleeved with an end screen lead insulation sleeve.

The above-mentioned technical scheme of the present invention has the following advantages compared with the prior art:

The high-voltage bushing end shield grounding shield and the high-voltage bushing end shield of the present invention can provide safe and reliable leakage for on-line monitoring of the high-voltage casing condition without changing the original reliable grounding structure of the casing end shield. According to the current measurement data, the present invention not only ensures the safe and reliable grounding of the end screen of the high-voltage bushing, but also provides an effective means for online monitoring of the insulation state of the bushing.

Description of drawings

In order to make the content of the present invention easier to understand clearly, the present invention will be described in further detail below according to specific embodiments of the present invention and in conjunction with the accompanying drawings, wherein

Fig. 1 is the schematic diagram of existing end screen grounding insulating cover;

Fig. 2 is the schematic diagram of the high-voltage bushing end shield grounding protective cover of the present invention;

Fig. 3 is the schematic diagram of the high-voltage bushing end screen of the present invention;

FIG. 4 is a schematic diagram of the connection between the end shield of the high-voltage bushing of the present invention and the grounding shield.

Reference symbols in the figure: 1-insulation cover, 2-O-shaped gasket, 3-outlet terminal, 4-T-shaped gasket, 10-ground shield inner cover, 11-measurement coil, 12-measurement wire plug connector, 13-Signal extraction cable, 14-Light-emitting device, 15-Shield lining, 16-Insulation ferrule, 17-First butt sealing groove, 20-Ground shield cover, 21-Second butt sealing groove, 30-End screen Lead extension rod, 31-spring part, 32-insulation sleeve, 40-end shield of high voltage bushing, 41-end shield of casing, 42-end shield lead wire, 43-end shield lead wire insulation sleeve.

Detailed ways

Example 1:

As shown in FIG. 2 , FIG. 3 and FIG. 4 , this embodiment provides a high-voltage bushing end shield grounding shield, which is installed on the high-voltage bushing end shield 40 , and the high-voltage casing end shield 40 includes a casing end shield The base 41 and the end shield lead 42 located on the casing end shield 41, the ground shield includes the ground shield inner shield 10 connected to the casing end shield 41, and the ground shield The ground shield outer cover 20 connected to the cover 10 and the end shield lead extension rod 30 connected with the end shield lead 42, wherein the end shield lead extension rod 30 passes through the ground shield inner cover 10 and the ground shield The cover and the outer cover 20 are connected, a measuring coil 11 is installed between the inner wall of the inner cover 10 of the grounding shield and the extension rod 30 of the end screen lead, and a measuring line plug connector 12 is installed along the outer wall of the inner cover 10 of the grounding shield. , the output terminal of the measurement coil 11 is connected to one end of the signal extraction line 13 , and the other end of the signal extraction line 13 is connected to the measurement line plug connector 12 .

The high-voltage bushing end shield grounding shield in this embodiment is installed on the high-voltage bushing end shield 40 , and the high-voltage casing end shield 40 includes a casing end shield 41 and is located on the casing end shield 41 The end shield lead 42, the ground shield includes the ground shield inner cover 10, the ground shield outer cover 20 and the end shield lead extension rod 30, wherein the casing end shield seat 41 and the ground shield inner cover 10 The inner cover 10 of the grounding shield is connected with the outer cover 20 of the grounding shield, and the outer cover 20 of the grounding shield is a reliable grounding body, thereby ensuring the safe and reliable grounding of the end screen 40 of the high-voltage bushing. The end shield lead 42 is connected with the end shield lead extension rod 30, so that the end shield lead wire of the casing is extended. When the high-voltage casing is actually in live operation, the leakage current of the main insulation of the high-voltage casing passes through the end shield lead. 42 is transmitted to the end shield lead extension rod 30, the end shield lead wire extension rod 30 is connected to the ground shield outer cover 20 through the ground shield inner cover 10, specifically, the ground shield outer cover 20 is installed on the inner cover 10 of the grounding shield and the extension rod 30 of the end shield lead, because the casing end shield 41 is a grounding body, and the casing end shield 41 and the ground shield The inner cover 10 is connected, the inner cover 10 of the grounding shield is connected with the outer cover 20 of the grounding shield, and the outer cover 20 of the grounding shield is connected with the extension rod 30 of the end screen lead, so the extension of the end shield lead can be ensured. Rod 30 is grounded reliably. When the high-voltage bushing carries out routine condition maintenance test or preventive test (off-line test), the end screen of high-voltage bushing will not be completely exposed to the air, thus ensuring the above test even in rainy or humid conditions. It can also be carried out in climatic weather, improving the time utilization rate during the on-site power outage process; and during the test, it is not necessary to disassemble the whole, the inner cover 10 of the grounding shield does not need to be disassembled, and the inner cover 10 of the grounding shield still protects the The end shield lead 42 is protected from the external environment, and the relevant test can be carried out only by opening the grounding shield cover 20, so the end shield 40 of the high-voltage bushing can be protected, and the high-voltage bushing can be effectively reduced. The number of disassembly and assembly times of the grounding shield of the end shield; a measuring coil 11 is installed between the inner wall of the inner shield 10 of the ground shield and the lead extension rod 30 of the end shield, and a measuring coil 11 is installed along the outer wall of the inner shield 10 of the ground shield. Measuring line plug connector 12, the output terminal of the measuring coil 11 is connected to one end of the signal extraction line 13, the other end of the signal extracting line 13 is connected to the measuring line plug connector 12, the measuring coil 11 is connected by electromagnetic induction According to the principle, the leakage current flowing through the end-screen lead extension rod 30 is measured, and the corresponding output signal is transmitted to the measurement line plug connector 12 through the signal extraction line 13, and the measurement line plug connector 12 is used to supply It is used for online monitoring of high-voltage bushing status to provide safe and reliable leakage current measurement data for online monitoring of high-voltage bushing status, and achieve the effect of live monitoring of high-voltage bushing status.

In order to intuitively judge the grounding condition of the end screen by visual observation, a light-emitting device 14 is also installed along the outer wall of the inner cover 10 of the grounding shield, and the light-emitting device 14 is connected to the signal extraction line 13, and the flow The leakage current passing through the end-screen lead extension rod 30 is transmitted to the light-emitting device 14 through the signal extraction line 13 , and the signal output to the light-emitting device 14 provides a DC input voltage for the light-emitting device 14 through the rectifier module. , to make the light-emitting device 14 emit light, only when the above-mentioned end screen is grounded reliably, the light-emitting device 14 will obtain a stable input voltage, so the light-emitting device 14 can be visually judged by the naked eye. In some cases, if the light-emitting device 14 flashes or does not light up, it can be judged that the end screen of the high-voltage bushing is poorly grounded or ungrounded, which serves as a warning for on-site inspection personnel.

A spring member 31 is provided in the middle of the end screen lead extension rod 30. When the grounding shield cover 20 presses the end screen lead wire extension rod 30, the spring member 31 will exert an opposite thrust, thereby ensuring that The grounding shield cover 20 and the end screen lead extension rod 31 are tightly connected. In order to prevent the leakage current signal of the end-screen lead extension rod 30 from being directly grounded through the inner cover 10 of the grounding shield, an insulating sleeve 32 is sleeved on the outer side of the end-screen lead extension rod 30. The contact surface between the rod 30 and the inner cover 10 of the grounding shield is small, and the phenomenon of poor contact is prone to occur. Therefore, the insulating sleeve 32 is installed between the contact end of the terminal lead 42 and the spring member 31 the end screen lead extension rod 30, so as to achieve the effect of insulation from the outer wall of the inner cover 10 of the grounding shield.

The inner wall of the ground shield inner cover 10 is provided with a shielding lining 15, and the shielding lining 15 is a magnetic shielding lining with high magnetic permeability, which is beneficial to ensure that the measurement data is not disturbed by an external strong magnetic field. An insulating ferrule 16 is provided between the measuring coil 11 and the shielding lining 15, and the measuring coil 11 is located between the insulating ferrule 16 and the end-screen lead extension rod 30, thereby serving as a fixing place. Describe the role of the measuring coil 11 and insulation.

A first butt sealing groove 17 and a connecting wire port are provided at the butt joint of the grounding shield inner cover 10 and the casing end screen 41, which are used to realize the connection between the grounding shield inner cover 10 and the casing end. Good connection and reliable sealing of the screen base 41 . The connection between the grounding shield outer cover 20 and the grounding shield inner cover 10 is provided with a second butt sealing groove 21 and a butting wire port, which are used to realize the connection between the grounding shield inner cover 10 and the grounding shield outer cover 20. Good connection and reliable sealing.

Embodiment 2:

This embodiment provides a high-voltage bushing end shield, which includes a casing end shield seat 41, an end shield lead 42 located on the casing end shield 41, and the high-voltage casing end shield grounding protection described in Embodiment 1 cover. Since the end shield of the high-voltage bushing includes the grounding shield described in the first embodiment, all the advantages of the first embodiment also have all the advantages of the second embodiment. In addition, the outer wall of the end shield lead 42 is sleeved with end shield lead wire insulation sleeve 43, through the function of insulation, the casing end shield 41 is realized as a grounding body, which is beneficial to the high voltage casing end shield 40. Reliable grounding.

To sum up, the technical solution of the present invention has the following advantages:

1. The high-voltage bushing end screen grounding shield of the present invention is installed on the high-voltage bushing end screen, and the high-voltage bushing end screen includes a casing end screen seat and an end screen located on the casing end screen seat. Lead wires, the grounding shield includes an inner shielding shield, an outer shielding grounding shield, and an extension rod for the end shield lead, wherein the end shielding base of the bushing is connected to the inner shielding grounding shield, and the inner shielding shielding It is connected to the outer cover of the grounding shield, which is a reliable grounding body, thereby ensuring the safe and reliable grounding of the end shield of the high-voltage bushing, and the end shield lead is connected to the end shield lead extension rod, Extend the lead wire of the end screen of the bushing. When the high-voltage bushing is actually in live operation, the leakage current of the main insulation of the high-voltage bushing is transmitted to the extension rod of the end screen lead through the end screen lead, and the end screen The lead extension rod passes through the inner cover of the grounding shield and is connected to the outer cover of the grounding shield. Since the end shield of the casing is a grounding body, it can ensure that the end shield lead extension rod is reliably grounded. When carrying out routine condition maintenance test or preventive test (off-line test), the end screen of high-voltage bushing will not be completely exposed to the air, so as to ensure that the above test can be carried out even in rainy or humid weather, improving the performance of the field. The time utilization rate during the power outage process; and during the test, it is not necessary to disassemble the whole, the inner cover of the grounding shield does not need to be disassembled, and only the outer cover of the grounding shield can be opened, and the relevant test can be carried out, so the end of the high-voltage bushing can be tested. The screen plays a protective role, effectively reducing the number of disassembly and assembly of the grounding shield at the end of the high-voltage bushing; a measuring coil is installed between the inner wall of the inner shield of the grounding shield and the lead extension rod of the end shield, and a measuring coil is installed along the grounding shield. The outer wall of the inner cover of the protective cover is installed with a measuring line plug connector, the output terminal of the measuring coil is connected with one end of the signal extraction line, and the other end of the signal extraction line is connected with the measuring line plug connector, and the measuring coil passes through the According to the principle of electromagnetic induction, the leakage current flowing through the end-screen lead extension rod is measured, and the corresponding output signal is transmitted to the measurement line plug connector through the signal extraction line, and the high-voltage bushing state is supplied through the measurement line plug connector. It is used in online monitoring to provide safe and reliable leakage current measurement data for online monitoring of high-voltage bushings, so as to achieve the effect of real-time monitoring of the status of high-voltage bushings.

2. According to the high-voltage bushing end shield grounding shield of the present invention, a light-emitting device is also installed along the outer wall of the inner cover of the grounding shield, and the light-emitting device is connected with the signal extraction line, and the flow through the The leakage current of the lead extension rod of the end screen is transmitted to the light-emitting device through the signal extraction line, and the signal output to the light-emitting device provides the DC input voltage for the light-emitting device through the rectifier module, so that the light-emitting device emits light, Only when the above-mentioned last screen is grounded reliably, the light-emitting device can obtain a stable input voltage. Therefore, the grounding of the final screen can be visually judged by observing the light-emitting situation of the light-emitting device with the naked eye. If the light-emitting device flickers or does not If the light is on, it can be judged that the terminal screen of the high-voltage bushing is poorly grounded or not grounded, which serves as a warning for on-site inspection personnel.

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, other different forms of changes or modifications can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. And the obvious changes or changes derived from this are still within the protection scope of the present invention.

Claims (10)

1. The utility model provides a high-tension bushing end screen ground connection protection casing, installs on the high-tension bushing end screen, the high-tension bushing end screen includes the terminal screen seat of sleeve pipe and is located end screen lead wire on the terminal screen seat of sleeve pipe, its characterized in that: the grounding protective cover comprises a grounding protective cover inner cover connected with the sleeve terminal screen seat, a grounding protective cover outer cover connected with the grounding protective cover inner cover and a terminal screen lead extension rod connected with the terminal screen lead, wherein the terminal screen lead extension rod penetrates through the grounding protective cover inner cover to be connected with the grounding protective cover outer cover, a measuring coil is installed between the inner wall of the grounding protective cover inner cover and the terminal screen lead extension rod, a measuring line plug is installed along the outer wall of the grounding protective cover inner cover, an output terminal of the measuring coil is connected with one end of a signal extraction line, and the other end of the signal extraction line is connected with the measuring line plug.

2. The high voltage bushing tap grounding shield of claim 1, wherein: and a light-emitting device is further installed along the outer wall of the inner cover of the grounding shield and is connected with the signal extraction line.

3. The high voltage bushing tap grounding shield of claim 1, wherein: and a spring component is arranged in the middle of the end screen lead wire extension rod.

4. A high voltage bushing tap grounding shield as claimed in claim 3, wherein: an insulating sleeve is sleeved outside the end screen lead extension rod and is arranged on the end screen lead extension rod between the end screen lead extension rod and the spring component.

5. The high voltage bushing tap grounding shield of claim 1, wherein: and a shielding lining is arranged on the inner wall of the inner cover of the grounding shield.

6. The high voltage bushing tap grounding shield of claim 5, wherein: an insulation clamping sleeve is arranged between the measuring coil and the shielding lining, and the measuring coil is located between the insulation clamping sleeve and the end screen lead extension rod.

7. The high voltage bushing tap grounding shield of claim 1, wherein: the butt joint of the grounding shield outer cover and the grounding shield inner cover is provided with a first butt joint sealing groove and a butt joint screw hole.

8. The high voltage bushing tap grounding shield of claim 1, wherein: and a second butt joint sealing groove and a connecting screw port are formed in the butt joint of the grounding shield inner cover and the sleeve terminal screen seat.

9. A high voltage bushing end screen, includes bushing end screen seat and is located end screen lead wire on the bushing end screen seat, its characterized in that: further comprising a high voltage bushing end screen grounding shield as claimed in any of claims 1-8.

10. A high voltage bushing tap as claimed in claim 9, wherein: and the outer wall of the end screen lead is sleeved with an end screen lead insulating sleeve.

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