Device for shielding space charge from interference of leakage current of 500kV arrester

Abstract

The utility model relates to the field of lightning arrester high pressure test, specifically discloses a device that shields space charge from interfering with 500kV lightning arrester leakage current, including the first casing and second casing of symmetrical arrangement, one end of first casing and one end of second casing hinge, the other end of first casing and the other end of second casing are detachably connected, the inner wall of first casing and second casing all is provided with insulating paper groove, and is provided with insulating paper in insulating paper groove. The utility model discloses the volume of shielding device is small, and the weight is light, and can be disassembled and assembled, and is firm, and can be used for lightning arrester leakage current test of different voltage grades, and through the insulating paper, and according to the number of layers of insulating paper of shielding demand replacement, increase and decrease, can effectively shield the influence of space charge in lightning arrester leakage current test, solves the problem that the accuracy of the existing shielding device is low and the reliability is poor for 500kV lightning arrester leakage current test result.

Description

Technical Field

[0001] This utility model relates to the field of high-voltage testing of surge arresters, and specifically discloses a device for shielding space charge from interfering with the leakage current of a 500kV surge arrester. Background Technology

[0002] Surge arresters are critical protective devices in power systems, primarily used to limit damage to power grid equipment and systems caused by lightning or switching overvoltages, playing a vital role in the safe and stable operation of the power system. To ensure the safe and reliable operation of surge arresters, preventative tests are necessary. A DC 1mA voltage and 0.75U... 1mA Leakage current testing under voltage is currently the most effective means of evaluating the performance and condition of surge arresters.

[0003] However, to ensure data accuracy, the test leads should maintain a 90° angle with the surge arrester. In high-voltage environments such as 500kV, the overall height of the surge arrester is close to 10 meters, making it difficult to achieve a 90° angle between the test leads and the arrester. When measuring the DC leakage current of the uppermost surge arrester, the influence of space charge causes the measured leakage current to be much greater than 50μA, affecting the accuracy of the measurement data and resulting in inaccurate test results. Consequently, it becomes impossible to make a correct judgment on the performance and condition of the surge arrester. Utility Model Content

[0004] The purpose of this invention is to provide a device for shielding the interference of space charge on the leakage current of a 500kV surge arrester, thereby solving the problems of low accuracy and poor reliability of existing shielding devices for 500kV surge arrester leakage current test results.

[0005] The specific solution of this utility model is as follows: A device for shielding space charge from interfering with the leakage current of a 500kV surge arrester includes: a first housing and a second housing arranged symmetrically, one end of the first housing and one end of the second housing being hinged together, the other end of the first housing and the other end of the second housing being detachably connected, and insulating paper grooves being provided on the inner walls of both the first housing and the second housing, with insulating paper placed inside the insulating paper grooves.

[0006] In some embodiments, a hinge pivot is provided between one end of the first housing and one end of the second housing, so that the first housing and the second housing are hinged together.

[0007] In some embodiments, bolts and nuts are also included. Threaded holes are provided on the other end of the first housing and the other end of the second housing. The bolt passes through the threaded holes on the first housing and the second housing in sequence to be threadedly connected to the nut.

[0008] In some embodiments, a latch is provided on the other end of the first housing and a hook is provided on the other end of the second housing. The latch and the hook are fastened together to fix the first housing and the second housing in place.

[0009] In some embodiments, the first housing is a first metal housing made of metal, and the second housing is a second metal housing made of metal. A terminal is provided on the outer wall of the first housing, and the first metal housing and the second metal housing are grounded through the terminal.

[0010] In some embodiments, the first housing is a first insulating housing made of insulating material, and the second housing is a second insulating housing made of insulating material.

[0011] In some embodiments, the insulating paper is multilayer insulating paper.

[0012] In some embodiments, a shielding layer is provided on the inner wall of both the first housing and the second housing, and an insulating paper is provided on the shielding layer.

[0013] Compared with the prior art, this utility model has the following advantages and beneficial effects: 1. This utility model's shielding device is small in size, lightweight, detachable, and securely fixed. It can be used for leakage current tests of surge arresters at different voltage levels, improving the accuracy, reliability, and safety of high-voltage surge arrester leakage current tests. The insulating paper effectively shields the influence of space charge in 500kV surge arrester leakage current tests, improving the accuracy of test data and thus enhancing the accuracy and reliability of 500kV surge arrester leakage current test results. The insulating paper is multi-layered, and the number of layers can be changed or increased according to shielding requirements, ensuring the thickness of the insulating paper meets shielding requirements. The first and second metal housings are grounded via terminals, or the first and second insulating housings are made of insulating material, further shielding the influence of idle charge and improving the accuracy of test data. The first and second housings can be freely opened and closed via hinges, allowing the shielding device to be securely fixed to the metal flange of the surge arrester, making it suitable for different types of surge arresters. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the device for shielding space charge from interfering with the leakage current of a 500kV surge arrester in an embodiment of this utility model.

[0015] Figure 2 This is a schematic diagram of the structure of the first housing in an embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of the structure of the second shell in an embodiment of the present invention.

[0017] Figure 4 This is a schematic diagram of the structure of the first housing, the second housing, and the hinge shaft in an embodiment of this utility model.

[0018] Figure 5 This is an application scenario diagram of the device for shielding space charge from interfering with the leakage current of a 500kV surge arrester, as described in this utility model embodiment.

[0019] Reference numerals: 1-Shielding device, 2-First housing, 3-Second housing, 4-Hinge shaft, 5-Screw hole, 6-Bolt, 7-Nut, 8-Terminal, 9-Insulating paper groove, 10-Insulating paper, 11-Surge arrester, 12-Equalizing ring, 13-Voltage multiplier cylinder, 14-Microammeter, 15-Pressure device. Detailed Implementation

[0020] The specific implementation method is described below with reference to the accompanying drawings.

[0021] Currently, interference shielding is often used to improve the accuracy of surge arrester leakage current tests.

[0022] For example, an auxiliary tool for facilitating leakage current testing of ultra-high voltage surge arresters includes a first joint, a second joint, a rotatable crossbar, a rotatable supporting insulating rod, and a telescopic insulating rod. The surge arrester has an upper flange at its top and a lower flange at its bottom. The lower flange is grounded, and the end of the high-voltage shielding wire is connected to the upper flange. One end of the rotatable supporting insulating rod has an annular clamp fitted onto the lower flange. The other end of the rotatable supporting insulating rod is connected to the rotatable crossbar via the first joint. Several insulating rings are provided on the rotatable crossbar, through which the high-voltage shielding wire passes. The upper end of the telescopic insulating rod is connected to the upper end of the rotatable supporting insulating rod via the second joint. This auxiliary tool can improve the efficiency of leakage current testing of ultra-high voltage surge arresters.

[0023] Although this auxiliary tool can maintain a 90° angle between the test leads and the surge arrester, reducing the influence of space charge, it is only suitable for surge arresters with lower voltage levels, not for those with higher voltage levels. This is because surge arresters with higher voltage levels can be 10 meters or even taller, placing higher demands on the auxiliary tool used for leakage current testing. Strict requirements are placed on its extension length and material. The taller the surge arrester, the more difficult it is to adjust the auxiliary tool. Furthermore, surge arresters are generally installed outdoors, and the impact of wind speed on the stability of the auxiliary tool must be considered. If the auxiliary tool tip over during DC withstand voltage testing, it may cause electric shock or other unsafe incidents. If adjacent lines are energized, the tipping of the auxiliary tool may also cause grounding tripping of adjacent lines, posing a safety hazard.

[0024] The high-voltage surge arrester upper section leakage current testing device includes a current-cutting ring and a leakage current testing component. The current-cutting ring and the leakage current testing component are electrically connected. The current-cutting ring is detachably installed below the equalizing ring of the high-voltage surge arrester. The current-cutting ring is a hollow current-cutting ring. When using the high-voltage surge arrester upper section leakage current testing device, the current-cutting ring is installed below the equalizing ring. The current formed by the stray capacitance caused by the equalizing ring is measured on the current-cutting ring. This current is numerically equivalent to the interference current formed by stray capacitance in the upper section of the surge arrester. Subtracting the current value when processing the experimental data yields more accurate leakage current data. The detachable installation of the current-cutting ring below the equalizing ring makes it convenient to use and reduces the workload of measurement.

[0025] Although this testing device can shield stray capacitance current and minute leakage current on the surface of the surge arrester insulator using shielded wires, thus improving the accuracy of the surge arrester leakage current test results to some extent, it involves numerous wiring connections, complex testing procedures, and the addition of two microammeters, increasing instrument and human reading errors. Furthermore, this device cannot directly test the DC leakage current of the uppermost surge arrester; the high-voltage test lead cannot be directly connected to the top of the uppermost surge arrester. If connected to the top, all wiring on the equalizing ring must be removed, reverting to the most primitive voltage application method, which is also susceptible to the influence of space charge.

[0026] Neither of the above two devices is suitable for high-voltage surge arrester leakage current testing, and neither can solve the problems of low accuracy and poor reliability of high-voltage surge arrester leakage current test results.

[0027] Devices that shield against space charge interference with the leakage current of a 500kV surge arrester, such as... Figure 1 , Figure 2 and Figure 3 As shown, it includes: a first housing 2 and a second housing 3 arranged symmetrically, one end of the first housing and one end of the second housing are hinged together, and the other end of the first housing and the other end of the second housing are detachably connected. Insulating paper grooves 9 are provided on the inner walls of both the first housing and the second housing, and insulating paper 10 is provided in the insulating paper grooves.

[0028] The device for shielding space charge from interfering with the leakage current of a 500kV surge arrester in this invention is referred to as shielding device 1.

[0029] The insulating paper 10 effectively shields the influence of space charge in the leakage current test of the 500kV surge arrester, improving the accuracy of the test data and thus enhancing the accuracy and reliability of the 500kV surge arrester leakage current test results. This shielding device 1 is small in size, lightweight, and detachable, and can be used for leakage current tests of surge arresters of different voltage levels. It can shield space charge caused by air humidity, test line angle, and grading ring corona discharge, making the test results more accurate and allowing for more accurate judgments and a more realistic assessment of the surge arrester's performance and condition. During the test, the shielding device 1 is firmly fixed, eliminating the risk of electric shock due to equipment collapse. Installation and operation are simple, and it offers high safety and reliability.

[0030] In some embodiments, such as Figure 4 As shown, a hinge shaft 4 is provided between one end of the first housing and one end of the second housing, so that the first housing 2 and the second housing 3 are hinged together by the hinge shaft 4.

[0031] The first housing 2 and the second housing 3 can be opened and closed freely through the hinge shaft 4, so that the shielding device 1 can be safely fixed on the metal flange of the surge arrester, which is applicable to different models of surge arresters 11.

[0032] In some embodiments, the device further includes a bolt 6 and a nut 7. Threaded holes 5 are provided on the other end of the first housing and the other end of the second housing. The bolt 6 passes through the threaded holes 5 on the first housing and the second housing in sequence to be threadedly connected to the nut 7.

[0033] The threaded connection allows for quick assembly and disassembly of the first housing 2 and the second housing 3, enabling the shielding device 1 to be quickly and securely fixed to the metal flange of the surge arrester.

[0034] There can be two bolts 6 and nuts 7. One screw hole 5 can be provided at the upper and lower parts of the other ends of the first and second housings, respectively. The bolt 6 passes through the screw holes 5 on the first and second housings in sequence and is threaded to the nut 7. The two threaded connections at the upper and lower parts can make the shielding device more securely fixed.

[0035] In some embodiments, a latch is provided on the other end of the first housing and a hook is provided on the other end of the second housing. The latch and the hook are fastened together to fix the first housing 2 and the second housing 3.

[0036] In some embodiments, the first housing 2 is a first metal housing made of metal, and the second housing 3 is a second metal housing made of metal. A terminal 8 is provided on the outer wall of the first housing, and the first metal housing and the second metal housing are grounded through the terminal 8.

[0037] By grounding the first and second metal casings through terminal 8, the influence of idle charge is further shielded, and the accuracy of the test data is further improved.

[0038] In some embodiments, the first housing 2 is a first insulating housing made of insulating material, and the second housing 3 is a second insulating housing made of insulating material.

[0039] The first and second insulating shells, made of insulating materials, further shielded the influence of idle charges, thereby further improving the accuracy of the test data.

[0040] In some embodiments, the insulating paper 10 is a multilayer insulating paper.

[0041] By using multiple layers of insulating paper 10, the number of insulating paper layers can be changed or increased or decreased according to shielding requirements or voltage levels, so that the thickness of the insulating paper meets the shielding requirements, better shielding space charges, and improving the accuracy, reliability and safety of the leakage current test of 500kV surge arresters.

[0042] In some embodiments, a shielding layer is provided on the inner wall of both the first housing and the second housing, and an insulating paper 10 is provided on the shielding layer.

[0043] The shielding effect is further improved by using a shielding layer to better shield space charges, thereby further improving the accuracy and reliability of the test.

[0044] like Figure 5 The following illustrates the actual application process of a device that shields against space charge interference with the leakage current of a 500kV surge arrester: First, the first housing 2 and the second housing 3 are fully opened to 180° using the hinge shaft 4 to facilitate the placement of the insulating paper 10 and its installation on the metal flange of the surge arrester. Then, the insulating paper 10 is inserted into the insulating paper groove, and its position is adjusted to ensure a tight fit between the insulating paper 10 and the shielding layer on the first and second housings. Next, the shielding device 1 is placed on the metal flange of the surge arrester, and the first housing 2 and the second housing 3 are closed using the hinge shaft 4 to completely cover the metal flange of the surge arrester. Then, the bolt 6 is threaded through the screw hole 5 and connected to the nut 7 to secure the first housing 2 and the second housing 3, ensuring the shielding device 1 is firmly attached to the metal flange of the surge arrester. Finally, one end of the grounding wire is inserted into the terminal 8, and the other end of the grounding wire is grounded, completing the installation of the shielding device 1 onto the metal flange of the surge arrester.

[0045] A voltage equalization ring 12 is installed at the top of the surge arrester. The voltage equalization ring 12 is connected to a microammeter 14 through a wire. A voltage multiplier cylinder 13 is installed below the microammeter 14, that is, the microammeter 14 is installed at the top of the voltage multiplier cylinder. The bottom of the voltage multiplier cylinder is grounded through a wire and connected to a pressurizing device 15. The surge arrester leakage current test device is installed and can be used to conduct surge arrester leakage current tests.

[0046] After the surge arrester leakage current test is completed, loosen nut 7 and remove bolt 6. Use hinge shaft 4 to fully open the first housing 2 and the second housing 3 to 180° and remove the shielding device 1 from the metal flange of the surge arrester to complete the quick disassembly of the shielding device.

[0047] This utility model is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model shall be included within the protection scope of this utility model.

Claims

1. A device for shielding space charge from interfering with the leakage current of a 500kV surge arrester, characterized in that, include: A first housing and a second housing are symmetrically arranged. One end of the first housing is hinged to one end of the second housing, and the other end of the first housing is detachably connected to the other end of the second housing. Insulating paper grooves are provided on the inner walls of both the first housing and the second housing, and insulating paper is provided in the insulating paper grooves.

2. The device for shielding space charge from interfering with the leakage current of a 500kV surge arrester according to claim 1, characterized in that: A hinge is provided between one end of the first housing and one end of the second housing, so that the first housing and the second housing can be hinged together.

3. The device for shielding space charge from interfering with the leakage current of a 500kV surge arrester according to claim 1, characterized in that: It also includes bolts and nuts. Threaded holes are provided on the other end of the first housing and the other end of the second housing. The bolts pass through the threaded holes on the first housing and the second housing in sequence to be threadedly connected to the nuts.

4. The device for shielding space charge from interfering with the leakage current of a 500kV surge arrester according to claim 1, characterized in that: A latch is provided on the other end of the first housing, and a hook is provided on the other end of the second housing. The latch and the hook are fastened together to fix the first housing and the second housing in place.

5. The device for shielding space charge from interfering with the leakage current of a 500kV surge arrester according to claim 1, characterized in that: The first housing is a first metal housing made of metal, and the second housing is a second metal housing made of metal. A terminal is provided on the outer wall of the first housing, and the first metal housing and the second metal housing are grounded through the terminal.

6. The device for shielding space charge from interfering with the leakage current of a 500kV surge arrester according to claim 1, characterized in that: The first housing is a first insulating housing made of insulating material, and the second housing is a second insulating housing made of insulating material.

7. The device for shielding space charge from interfering with the leakage current of a 500kV surge arrester according to claim 1, characterized in that: The insulating paper is multi-layered insulating paper.

8. The device for shielding space charge from interfering with the leakage current of a 500kV surge arrester according to claim 1, characterized in that: Both the first and second housings have a shielding layer on their inner walls, and the shielding layer is covered with insulating paper.

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