A shielding device

Abstract

The present application relates to the technical field of power maintenance, and particularly relates to a shielding device. The shielding device comprises a shielding cloth, an inner shrinkable rope, an outer shrinkable rope and a lifting assembly. The shielding cloth has a first end, a second end, an inner ring edge and an outer ring edge. The first end is detachably connected with the second end. After the first end and the second end are connected, the shielding cloth is arranged in a ring structure. The inner shrinkable rope passes through the inner ring edge of the shielding cloth. After the inner shrinkable rope is stretched, the inner ring edge of the shielding cloth is tightened. The outer shrinkable rope passes through the outer ring edge of the shielding cloth. After the outer shrinkable rope is stretched, the outer ring edge of the shielding cloth is tightened. The lifting assembly supports the inner shrinkable rope and the outer shrinkable rope. The lifting assembly can lift or lower the shielding cloth. The shielding device uses the lifting assembly to send the shielding cloth to the equalizing ring, so that a high-altitude operation vehicle is not needed, and a person does not need to climb on the lightning arrester to operate, thereby greatly reducing the workload and reducing the operation risk.

Description

Technical Field

[0001] This invention relates to the field of power maintenance technology, and in particular to a shielding device. Background Technology

[0002] Zinc oxide surge arresters are crucial overvoltage protection devices in substations. To assess the performance of surge arresters during substation operation, periodic outage preventative tests are typically required. Testing the DC 1mA reference voltage (U1mA, hereinafter referred to as reference voltage) and the leakage current at 0.75 times the DC 1mA reference voltage (I0.75U1mA, hereinafter referred to as leakage current) is one of the main outage preventative test items. 220kV and above surge arresters are usually composed of multiple sections (e.g., a 500kV surge arrester typically consists of an upper, middle, and lower section). An equipotential bonding ring is installed on the uppermost section to equalize the electric field between the high-voltage side of the surge arrester and the metal flange. This arrangement places the equipotential bonding ring relatively close to the lower metal flange of the uppermost surge arrester section.

[0003] During preventative testing under power outage maintenance conditions, the high-voltage side of the surge arrester is grounded through a line grounding switch or grounding wire, meaning the equipotential ring maintains zero potential. Therefore, the leakage current value I0.75U1mA of the uppermost surge arrester is typically measured by applying voltage to the lower metal flange of the uppermost surge arrester and using a high-voltage meter. However, due to time, maintenance conditions, and equipment limitations during on-site testing, the equipotential ring is usually not removed. Consequently, the zero-potential equipotential ring is close to the lower metal flange of the uppermost surge arrester, generating a strong stray current. This stray current is measured along with the leakage current, leading to an overestimation of the leakage current and inaccurate measurement results.

[0004] To eliminate the influence of the grading ring on the leakage current test results, a shielding method can be used to block stray currents in the space between the grading ring and the metal flange. This ensures that the current value indicated by the DC microammeter is the leakage current flowing through the zinc oxide varistor, improving measurement accuracy. Existing technology provides a shielding cover, which is installed on the lower metal flange of the uppermost surge arrester during preventative testing, thereby blocking stray currents in the space between the grading ring and the metal flange. However, since the lower metal flange of the uppermost surge arrester is usually located high above the ground, the shielding cover must be installed using an aerial work platform, which significantly increases workload and operational risks.

[0005] Therefore, there is an urgent need for a shielding device to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a shielding device that can achieve the purpose of shielding the surge arrester without the need for an aerial work platform during use.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] A shielding device, comprising:

[0009] The shielding cloth has a first end, a second end, an inner ring edge, and an outer ring edge. The first end and the second end are detachably connected. After the first end and the second end are connected, the shielding cloth is arranged in a ring structure.

[0010] An inner shrink rope passes through the inner ring edge of the shielding cloth. When the inner shrink rope is stretched, the inner ring edge of the shielding cloth tightens.

[0011] An outer shrink rope passes through the outer ring edge of the shielding cloth. When the outer shrink rope is stretched, the outer ring edge of the shielding cloth tightens.

[0012] A lifting assembly supports the inner and outer retractable ropes, and the lifting assembly is capable of raising or lowering the shielding fabric.

[0013] As a preferred technical solution of the above-mentioned shielding device, an inner rope loop is formed along the inner ring of the shielding cloth. The inner rope loop has two first openings. One end of the inner contraction rope passes through the two openings of the inner rope loop, and the two ends of the inner contraction rope are respectively located at the two first openings.

[0014] As a preferred technical solution of the above-mentioned shielding device, it also includes an inner tension rope, which is disposed on the shielding cloth.

[0015] As a preferred technical solution of the above-mentioned shielding device, the inner tension rope and the inner contraction rope are arranged symmetrically along the central axis of the ring-shaped shielding cloth.

[0016] As a preferred technical solution of the above-mentioned shielding device, an outer rope loop is formed on the outer ring of the shielding cloth. The outer rope loop has two second openings. One end of the outer contraction rope passes through the two openings of the outer rope loop, and the two ends of the outer contraction rope are respectively located at the two second openings.

[0017] As a preferred technical solution of the above-mentioned shielding device, it further includes an outer tension rope, which is disposed on the shielding cloth and below the inner tension rope.

[0018] As a preferred technical solution of the above-mentioned shielding device, the outer tension rope and the outer contraction rope are arranged symmetrically along the central axis of the ring-shaped shielding cloth.

[0019] As a preferred technical solution of the above-mentioned shielding device, the lifting assembly includes four pulleys and two lifting rods. The pulleys are arranged above the lifting rods, and each lifting rod is provided with two pulleys. The pulleys on each lifting rod are arranged vertically.

[0020] As a preferred technical solution for the aforementioned shielding device, the lifting rod is a telescopic rod.

[0021] As a preferred technical solution of the above-mentioned shielding device, the first end of the shielding cloth and the second end of the shielding cloth are bonded together by hook and loop fastener.

[0022] Beneficial effects of this invention:

[0023] The shielding cloth can be raised to the surge arrester using the lifting assembly. Since the first and second ends of the shielding cloth are detachably connected, they form an umbrella-like structure. The inner and outer tightening ropes pass through the inner and outer rings of the shielding cloth, respectively. Pulling these ropes tightens the shielding cloth, connecting the first and second ends and securing it. This allows the shielding cloth to surround the equalizing ring of the surge arrester, thus blocking stray currents between the equalizing ring and the metal flange. This ensures that the current value indicated by the DC microammeter is the leakage current flowing through the zinc oxide varistor, improving measurement accuracy.

[0024] The equipotential ring, which is at zero potential, is completely wrapped with shielding cloth to shield stray currents between the metal flange and the equipotential ring. Since the equipotential ring is relatively high off the ground, this device uses a lifting assembly to deliver the shielding cloth to the equipotential ring, eliminating the need for an aerial work platform or personnel to climb onto the surge arrester for operation, significantly reducing workload and operational risks. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the shielding device provided in an embodiment of the present invention;

[0027] Figure 2 This is a top view of the shielding cloth in its closed state according to an embodiment of the present invention;

[0028] Figure 3This is a top view of the shielding cloth provided in the embodiment of the present invention in its open state;

[0029] Figure 4 This is a top view of the shielding cloth provided in the embodiment of the present invention in its closed state, which has an inner shrink rope, an outer shrink rope, an inner stretch rope and an outer stretch rope.

[0030] Figure 5 This is a schematic diagram of the shielding device provided in the embodiment of the present invention in the state where the shielding cloth is open;

[0031] Figure 6 This is a schematic diagram of the shielding device provided in the embodiment of the present invention in the state where the shielding cloth is open.

[0032] In the picture:

[0033] 1. Shielding cloth; 11. Inner rope loop; 12. Outer rope loop; 2. Inner contraction rope; 3. Outer contraction rope; 4. Hook and loop; 5. Inner tension rope; 6. Outer tension rope; 7. Lifting rod; 8. Pulley; 9. Lightning arrester; 10. Equalizing ring. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0035] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0038] In the existing technology, the device to avoid the influence of the surge arrester's equalizing ring on the DC leakage current test needs to be installed on the surge arrester by an aerial work platform, which makes the installation cumbersome and increases the operational risk.

[0039] To address these issues, the present invention provides a shielding device.

[0040] like Figure 1-6 As shown, the shielding device includes a shielding cloth 1, an inner retractable rope 2, an outer retractable rope 3, and a lifting assembly. The shielding cloth 1 has a first end, a second end, an inner ring edge, and an outer ring edge. The first end and the second end are detachably connected. After the first end and the second end are connected, the shielding cloth 1 is arranged in a ring structure, so that the inner ring edge and the outer ring edge are arranged in concentric circles. The inner retractable rope 2 passes through the inner ring edge of the shielding cloth 1. When the inner retractable rope 2 is stretched, the inner ring edge of the shielding cloth 1 tightens. The outer retractable rope 3 passes through the outer ring edge of the shielding cloth 1. When the outer retractable rope 3 is stretched, the outer ring edge of the shielding cloth 1 tightens. The lifting assembly supports the inner retractable rope 2 and the outer retractable rope 3, and the lifting assembly can raise or lower the shielding cloth 1.

[0041] The shielding cloth 1 can be raised to the surge arrester 9 using the lifting assembly. Since the first and second ends of the shielding cloth 1 are detachably connected, after the first and second ends are connected, the shielding cloth 1 forms an umbrella-shaped structure. Because the inner shrink rope 2 passes through the inner ring edge of the shielding cloth 1 and the outer shrink rope 3 passes through the outer ring edge, pulling and tightening the inner and outer shrink ropes 2 and 3 connects the first and second ends of the shielding cloth 1 and tightens it. This allows the shielding cloth 1 to surround the equalizing ring 10 of the surge arrester 9, thereby blocking stray currents between the equalizing ring 10 and the metal flange, ensuring that the current value indicated by the DC microammeter is the leakage current flowing through the zinc oxide valve plate, thus improving measurement accuracy.

[0042] The equipotential ring 10, which is at zero potential, is completely wrapped with shielding cloth 1, thereby achieving the effect of shielding the stray current in the space between the metal flange and the equipotential ring 10. Since the equipotential ring 10 is relatively high off the ground, this device uses a lifting assembly to send the shielding cloth 1 to the equipotential ring 10, thus eliminating the need for an aerial work platform or for personnel to climb onto the surge arrester 9 for operation, greatly reducing workload and lowering operational risks.

[0043] like Figures 2-4 As shown, the first end of the shielding cloth 1 and the second end of the shielding cloth 1 are bonded together by hook and loop fastener 4 or connected by snap fasteners. In this embodiment, it is preferable that the first end of the shielding cloth 1 and the second end of the shielding cloth 1 are bonded together by hook and loop fastener 4. This way, the connection between the first end and the second end of the shielding cloth 1 can be achieved without a large external force.

[0044] Optionally, in this embodiment, an inner rope loop 11 is formed along the inner circumference of the shielding cloth 1. The inner rope loop 11 has two first openings, and one end of the inner contraction rope 2 passes through the two first openings of the inner rope loop 11. The two ends of the inner contraction rope 2 are respectively located at the two first openings. It can be understood that the two first openings of the inner rope loop 11 are respectively located at the first end and the second end of the shielding cloth 1. When it is necessary to surround the pressure equalization ring 10 with the shielding cloth 1, the inner contraction ropes 2 exposed at the inner rope loop 11 need to be brought closer to each other so that the first end and the second end of the shielding cloth 1 are connected. This is how the purpose of surrounding the shielding cloth 1 in an umbrella-like structure can be achieved.

[0045] An outer rope loop 12 is formed along the outer circumference of the shielding cloth 1. The outer rope loop 12 has two second openings. One end of the outer contraction rope 3 passes through the two openings of the outer rope loop 12, and the two ends of the outer contraction rope 3 are located at the two second openings respectively. It can be understood that the two second openings of the outer rope loop 12 are respectively located at the first end and the second end of the shielding cloth 1. When it is necessary to surround the pressure equalization ring 10 with the shielding cloth 1, the outer contraction ropes 3 exposed at the outer rope loop 12 need to be brought closer together to connect the first end and the second end of the shielding cloth 1. The inner contraction rope 2 and the outer contraction rope 3 cooperate with each other to quickly connect the first end and the second end of the shielding cloth 1, thus achieving the purpose of surrounding the shielding cloth 1 in an umbrella-like structure.

[0046] The inner loop 11 is obtained by sewing the inner ring edge with sewing thread, and the outer loop 12 is obtained by sewing the outer ring edge with sewing thread.

[0047] Optionally, in this embodiment, the shielding device further includes an inner tension rope 5 and an outer tension rope 6, both of which are disposed on the shielding cloth 1. The outer tension rope 6 is disposed below the inner tension rope 5. The function of the inner tension rope 5 is to enable the shielding cloth 1 to unfold, thereby achieving the purpose of unfolding the tightened shielding cloth 1.

[0048] Specifically, the inner tension rope 5 and the inner contraction rope 2 are arranged symmetrically along the central axis of the annular shielding cloth 1. Similarly, the outer tension rope 6 and the outer contraction rope 3 are arranged symmetrically along the central axis of the annular shielding cloth 1. Compared to other locations on the shielding cloth 1, the arrangement of the inner tension rope 5 and the outer tension rope 6 in this embodiment allows for the rapid unfolding of the shielding cloth 1. Furthermore, the arrangement in this embodiment also reduces the pulling force required for opening. It is understood that the inner tension rope 5 is positioned at the inner edge of the shielding cloth 1 in the direction where the radial line of the first opening rotates 180°, and the outer tension rope 6 is positioned at the outer edge of the shielding cloth 1 in the direction where the radial line of the second opening rotates 180°.

[0049] When both the outer shrink rope 3 and the inner shrink rope 2 are tightened, the outer and inner ring edges of the shielding cloth 1 are tightened, thus achieving the purpose of shielding the equalizing ring 10. After the test is completed, the tightened outer and inner ring edges of the shielding cloth 1 can be unfolded again by pulling the outer tension rope 6 and the inner tension rope 5. That is, the tightening and unfolding of the outer and inner ring edges of the shielding cloth 1 can be achieved by the outer shrink rope 3, the inner shrink rope 2, the outer tension rope 6, and the inner tension rope 5. The outer shrink rope 3, the inner shrink rope 2, the outer tension rope 6, and the inner tension rope 5 can be made of insulating material, such as nylon rope.

[0050] Optionally, such as Figure 5 and Figure 6 As shown, in order to deliver the shielding cloth 1 to the equalizing ring 10, in this embodiment, the lifting assembly includes four pulleys 8 and two lifting rods 7. The pulleys 8 are positioned above the lifting rods 7, and each lifting rod 7 has two pulleys 8 arranged vertically. The inner retraction rope 2, outer retraction rope 3, inner tension rope 5, and outer tension rope 6 are respectively wound around the corresponding pulleys 8. In this way, with the cooperation of the inner retraction rope 2, outer retraction rope 3, inner tension rope 5, outer tension rope 6, pulleys 8, and lifting rods 7, the shielding cloth 1 can be delivered to the equalizing ring 10. This eliminates the inconvenience of using an aerial work platform for lifting, improves operational safety, and reduces shielding costs. When the shielding cloth 1 is in the unfolded state, the free ends of the inner retraction rope 2, outer retraction rope 3, inner tension rope 5, and outer tension rope 6 should be positioned so that they can be pulled by the operator.

[0051] The inner shrink rope 2 and the outer shrink rope 3 can be set on the upper and lower pulleys 8 as needed. The specific setting position is not particularly limited, as long as it can achieve the stretching of the shielding cloth 1. The inner tension rope 5 and the outer tension rope 6 can be set on the upper and lower pulleys 8 as needed. The specific setting position is not particularly limited, as long as it can achieve the tightening of the shielding cloth 1.

[0052] The pulley 8 makes it easier to pull the inner retraction rope 2, outer retraction rope 3, inner tension rope 5, and outer tension rope 6. The function of the pulley 8 is to transmit the tension of the inner retraction rope 2, outer retraction rope 3, inner tension rope 5, and outer tension rope 6. Thus, pulling the outer retraction rope 3, inner retraction rope 2, outer tension rope 6, and inner tension rope 5 at the bottom of the lifting rod 7 can control the tightening and unfolding of the outer and inner ring edges of the shielding cloth 1 located at the top of the lifting rod 7.

[0053] Optionally, in this embodiment, the lifting rod 7 is a telescopic rod. This allows the shielding cloth 1 to be raised to the required height as needed, thus making it suitable for equalizing rings 10 at different heights.

[0054] When the inner retraction rope 2, outer retraction rope 3, inner tension rope 5, and outer tension rope 6 are pulled, there is a possibility that these four ropes may detach from the pulley 8. Therefore, in this embodiment, the lifting assembly also includes a limiting protective cover. The protective cover is fixedly mounted on the lifting rod 7, and the pulley 8 is positioned within the space formed by the protective cover. The protective cover is used to prevent the inner retraction rope 2 and outer retraction rope 3 from detaching from the pulley 8. The distance between the pulley 8 and the limiting protective cover is such that none of the inner retraction rope 2, outer retraction rope 3, inner tension rope 5, and outer tension rope 6 can pass through, thus preventing the shielding cloth 1 from losing support during operation.

[0055] like Figure 5 and Figure 6 As shown, the shielding cloth 1 has a ring-shaped structure. During use, the surge arrester 9's column passes through the hollow circle of the shielding cloth 1. To allow the surge arrester 9's column to pass through the hollow circle of the shielding cloth 1, an opening is provided in the radial direction of the shielding cloth 1. The ring-shaped shielding cloth 1 is opened and closed using hook and loop fasteners 4. Before use, the hook and loop fasteners 4 are opened to allow the surge arrester 9's column to pass through the hollow circle of the shielding cloth 1. After passing through, the hook and loop fasteners 4 are fastened again.

[0056] Then, secure the outer retraction rope 3, inner retraction rope 2, outer tension rope 6, and inner tension rope 5. Next, slowly raise the lifting rod 7. At this point, the outer retraction rope 3, inner retraction rope 2, outer tension rope 6, and inner tension rope 5 will be under stress and will cause the shielding cloth 1 to gradually rise. The raising will stop when the upper surface of the shielding cloth 1 contacts the equalizing ring 10.

[0057] To achieve a tight wrapping effect of the shielding cloth 1, inner and outer shrink ropes are installed along the inner and outer ring edges of the shielding cloth 1. The outer shrink rope 3 and inner shrink rope 2 can then be slowly pulled in from the ground. This, through the outer rope loop 12 and inner rope loop 11 of the shielding cloth 1, gradually tightens the outer and inner ring edges of the shielding cloth 1 until the shielding cloth 1 completely wraps around the equalizing ring 10, achieving a good shielding effect. At this point, the reference voltage and leakage current can be tested.

[0058] After the test is completed, slowly pull the outer tension rope 6 and the inner tension rope 5, while slowly releasing the outer contraction rope 3 and the inner contraction rope 2. This will slowly unfold the outer and inner ring edges of the shielding cloth 1 that have been tightened. After unfolding, slowly lower the insulating rod to drop the shielding cloth 1, thus completing the entire usage process.

[0059] Furthermore, the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A shielding device, characterized in that, include: The shielding cloth (1) has a first end, a second end, an inner ring edge and an outer ring edge. The first end and the second end are detachably connected. After the first end and the second end are connected, the shielding cloth (1) is arranged in a ring structure. The inner shrink rope (2) passes through the inner ring edge of the shielding cloth (1). After the inner shrink rope (2) is stretched, the inner ring edge of the shielding cloth (1) tightens. The outer shrink rope (3) passes through the outer ring edge of the shielding cloth (1). After the outer shrink rope (3) is stretched, the outer ring edge of the shielding cloth (1) tightens. By pulling and tightening the inner shrink rope (2) and the outer shrink rope (3), the first end of the shielding cloth (1) can be connected to the second end, and the shielding cloth (1) can be tightened to form an umbrella-shaped structure so that the shielding cloth (1) surrounds the equalizing ring of the surge arrester. The lifting assembly supports the inner retractable rope (2) and the outer retractable rope (3), and the lifting assembly is capable of raising or lowering the shielding cloth (1).

2. The shielding device according to claim 1, characterized in that, The inner ring of the shielding cloth (1) has an inner rope loop (11) formed thereon, the inner rope loop (11) having two first openings, and the two ends of the inner retractable rope (2) are respectively located at the two first openings.

3. The shielding device according to claim 2, characterized in that, It also includes an inner tension rope (5), which is disposed on the shielding cloth (1). The inner tension rope (5) and the inner contraction rope (2) are arranged symmetrically along the central axis of the ring-shaped shielding cloth (1). By pulling the inner tension rope (5), the inner ring of the shielding cloth (1) that has been tightened is re-unfolded.

4. The shielding device according to claim 3, characterized in that, The outer ring of the shielding cloth (1) has an outer rope loop (12) formed thereon, the outer rope loop (12) has two second openings, and the two ends of the outer retractable rope (3) are respectively located at the two second openings.

5. The shielding device according to claim 4, characterized in that, It also includes an outer tension rope (6), which is disposed on the shielding cloth (1) and below the inner tension rope (5). The outer tension rope (6) and the outer contraction rope (3) are arranged symmetrically along the central axis of the ring-shaped shielding cloth (1). By pulling the outer tension rope (6), the outer ring of the shielding cloth (1) that has been tightened is re-unfolded.

6. The shielding device according to claim 1, characterized in that, The lifting assembly includes four pulleys (8) and two lifting rods (7). The pulleys (8) are located above the lifting rods (7), and each lifting rod (7) has two pulleys (8). The pulleys (8) on each lifting rod (7) are arranged vertically.

7. The shielding device according to claim 6, characterized in that, The lifting rod (7) is a telescopic rod.

8. The shielding device according to claim 1, characterized in that, The first end of the shielding cloth (1) is bonded to the second end of the shielding cloth (1) by hook and loop fastener (4).

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