A dc microgrid device protection device and a protection method thereof

Abstract

The application belongs to the field of power grid protection, and particularly relates to a DC micro-grid equipment protection device and a protection method thereof. The device comprises a lightning arrester body, the lightning arrester body is located on an insulating plate, a lower clamping assembly is installed on the insulating plate, a grounding end at the bottom of the lightning arrester body is inserted into the lower clamping assembly, a high-voltage end at the top of the lightning arrester body is inserted into an upper clamping assembly, the lower clamping assembly comprises a conductive component, the conductive component is connected with a grounding wire, the conductive component is in contact with the grounding end, a lightning protection component is arranged on the upper clamping assembly, the lightning protection component is connected with a high-voltage bus, and the lightning protection component is in contact with the high-voltage end. Compared with the prior art, the device does not need other tools, can quickly remove the lightning arrester body for maintenance and replacement, is suitable for high-altitude operation environment of the lightning arrester body, has the characteristics of convenient installation and later maintenance, and can quickly operate in the early stage of the DC micro-grid and the later regular maintenance process.

Description

Technical Field

[0001] This invention belongs to the field of power grid protection, specifically relating to a protection device and method for DC microgrid equipment. Background Technology

[0002] DC microgrids are microgrids composed of DC power and are an important component of future smart power distribution systems. They are of great significance for promoting energy conservation and emission reduction and achieving sustainable energy development.

[0003] To protect electrical equipment on a DC microgrid, surge arresters are often installed on the power network of the DC microgrid. These surge arresters are typically mounted on utility poles or power towers, such as... Figure 5 As shown, in the prior art, the surge arrester has a high-voltage end at the top and a grounding end at the bottom. The high-voltage end is connected to the high-voltage busbar through a nut, and the grounding end is connected to the grounding wire through a nut. The surge arrester itself is fixed to the insulating plate by screws, welding, or other means. Since the power network needs to be maintained regularly in DC microgrid systems, when the surge arrester needs to be removed for inspection, replacement, or other maintenance work, the staff needs to first remove the nuts on the high-voltage end and the grounding end, and then remove the surge arrester as a whole. Since the surge arrester is often in a high position, its maintenance work is very inconvenient. Summary of the Invention

[0004] The purpose of this invention is to provide a protection device and method for DC microgrid equipment to solve the problems in the prior art. The technical solution adopted by this invention is as follows: A DC microgrid equipment protection device includes a surge arrester body, the surge arrester body is located on an insulating plate, a lower snap-fit ​​assembly is installed on the insulating plate, the grounding terminal at the bottom of the surge arrester body is inserted into the lower snap-fit ​​assembly, and the high-voltage terminal at the top of the surge arrester body is inserted into an upper snap-fit ​​assembly. The lower snap-fit ​​assembly includes a conductive component, which is connected to a grounding wire and is in contact with the grounding terminal. The upper snap-fit ​​assembly is equipped with a lightning protection component, which is connected to the high-voltage busbar and is in contact with the high-voltage end.

[0005] Furthermore, the conductive component is a circular ring structure, which is sleeved on the grounding terminal, and a gap is provided between the inner surface of the conductive component and the grounding terminal; The lower snap-fit ​​assembly also includes a conductive sheet connected to the inner side of the conductive component, the conductive sheet abutting against the grounding terminal.

[0006] Furthermore, the conductive sheet has a "U" shaped structure, with one side connected to the inner side of the conductive component and the other side abutting against the grounding terminal. A first elastic element is provided inside the opening of the conductive sheet, and the first elastic element is in a compressed state.

[0007] Furthermore, multiple conductive sheets are circumferentially distributed around the high-voltage end.

[0008] Furthermore, the conductive component is a circular ring structure, which is sleeved on the grounding end, the grounding end is threaded to the lower nut, and the top of the conductive component abuts against the lower nut; The lower snap-fit ​​assembly also includes a lower insulating shell, which is connected to the bottom of the insulating plate. The lower insulating shell has a hollow structure. The grounding terminal passes through the insulating plate and is located inside the lower insulating shell. The bottom of the lower insulating shell is connected to a fixing base, and the top of the fixing base supports the bottom of the conductive component. A through hole is provided on the side of the lower insulating shell, and the grounding wire is connected to the conductive component through the through hole.

[0009] Furthermore, an insulating sleeve is fixedly connected to the top of the fixing base, the insulating sleeve is threadedly connected to the grounding end, the top of the insulating sleeve abuts against the bottom of the conductive component, and a limiting part is provided on the lower circumferential surface of the fixing base, the limiting part abuts against the bottom of the lower insulating shell.

[0010] Furthermore, the upper snap-fit ​​assembly includes an upper insulating shell, which is a hollow structure and is threadedly connected to the high-voltage end. The top of the upper insulating shell is connected to the lightning protection component, and the bottom of the lightning protection component abuts against the high-voltage end.

[0011] Furthermore, the hollow portion of the upper insulating shell has a stepped hole structure, and an annular cavity is formed between the upper inner surface of the upper insulating shell and the peripheral surface of the high-voltage end. An annular protrusion is provided on the lower peripheral surface of the lightning protection component, and the annular protrusion is located inside the annular cavity. An annular cover plate is connected to the top of the upper insulating shell, and the lightning protection component passes through the annular cover plate. A second elastic element is provided between the top of the annular protrusion and the bottom of the annular cover plate.

[0012] Furthermore, the lightning protection component has a blind hole at its bottom, through which it is fitted onto the top of the high-voltage end, and a lightning rod is fixedly connected to the top of the lightning protection component.

[0013] A protection method for DC microgrid equipment, the method comprising: Insert the grounding terminal at the bottom of the surge arrester body into the lower snap-fit ​​assembly on the insulating plate, and insert the high-voltage terminal at the top of the surge arrester body into the upper snap-fit ​​assembly. The grounding terminal is connected to the grounding wire through the conductive part of the lower snap-fit ​​assembly; The high-voltage end is connected to the high-voltage busbar through the lightning protection component of the upper clamping assembly; During maintenance, first remove the upper snap-fit ​​assembly to disconnect the surge arrester from the high-voltage end, then remove the surge arrester body to disconnect the grounding end from the conductive parts.

[0014] The present invention has the following advantages: Compared with the prior art, the present invention does not require the use of other tools and can quickly remove the surge arrester body for inspection and replacement. It is suitable for high-altitude operation environments of surge arrester body and has the characteristics of convenient installation and subsequent maintenance. It can be carried out quickly in the early stage of DC microgrid construction and later periodic maintenance. Moreover, during the disassembly process, the workers can avoid contact with conductive parts, protect the workers, and avoid factors such as leakage that may endanger the safety of the workers. Attached Figure Description

[0015] Figure 1 This is a front view schematic diagram of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 for Figure 1 Enlarged view of point B in the middle; Figure 4 This is a schematic diagram showing the distribution of conductive sheets; Figure 5 This is a schematic diagram of existing technology; In the diagram, 1-power grid support component, 2-insulating plate, 201-bracket, 202-round hole, 203-positioning ring, 3-surge arrester body, 301-support part, 302-grounding end, 303-high voltage end, 4-lower snap-fit ​​assembly, 401-lower insulating shell, 402-conductive component, 403-conductive sheet, 404-first elastic element, 405-fixed seat, 406-insulating sleeve, 407-connector, 5-upper snap-fit ​​assembly, 501-upper insulating shell, 502-annular cover plate, 503-second elastic element, 6-surge arrester component, 601-, 7-grounding wire, 8-conductor. Detailed Implementation

[0016] The following will be based on embodiments of the present invention. Figures 1-5 The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0017] A DC microgrid equipment protection device includes a surge arrester body 3, the surge arrester body 3 is located on an insulating plate 2, a lower snap-fit ​​assembly 4 is installed on the insulating plate 2, the grounding terminal 302 at the bottom of the surge arrester body 3 is inserted into the lower snap-fit ​​assembly 4, and the high voltage terminal 303 at the top of the surge arrester body 3 is inserted into an upper snap-fit ​​assembly 5. The lower snap-fit ​​assembly 4 includes a conductive component 402, which is connected to the grounding wire 7 and is in contact with the grounding terminal 302. The upper snap-fit ​​assembly 5 is provided with a lightning protection component 6, which is connected to the high-voltage busbar and is in contact with the high-voltage end 303.

[0018] refer to Figure 1 , Figure 5 The surge arrester body 3 is a prior art technology. It has a high-voltage terminal 303 on the top and a grounding terminal 302 on the bottom. Both the grounding terminal 302 and the high-voltage terminal 303 are screw structures. The surge arrester component 6 can be connected to the high-voltage bus on the DC microgrid through the conductor 8, and the grounding wire 7 can be connected to the ground busbar, so that the surge arrester body 3 and the electrical equipment on the DC microgrid form a parallel relationship to protect the electrical equipment on the DC microgrid from the hazards of high transient overvoltage.

[0019] The insulating board 2 is existing technology. It can be fixed to the power grid support component 1 by the bracket 201. The function of the power grid support component 1 is to support the power lines on the DC microgrid. It can be a power pole or a power tower.

[0020] In practice, firstly, the grounding terminal 302 at the bottom of the surge arrester body 3 is inserted into the lower locking assembly 4 on the insulating plate 2. The lower locking assembly 4 fixes the grounding terminal 302 and makes the conductive component 402 contact the grounding terminal 302. At this time, the entire surge arrester body 3 is fixed on the insulating plate 2. Then, the high-voltage terminal 303 at the top of the surge arrester body 3 is inserted into the upper locking assembly 5, making the surge arrester component 6 contact the high-voltage terminal 303. The surge arrester component 6 and the conductive component 402 are made of metal for the purpose of conducting electricity to form the circuit structure of the surge arrester body 3. During later maintenance, the upper clamping component 5 is first detached from the surge arrester component 6, and then the surge arrester body 3 is lifted and removed as a whole, so that the conductive component 402 is detached from the surge arrester body 3. The entire surge arrester body 3 can then be removed. Compared with existing technologies, no other tools are needed, and the surge arrester body 3 can be quickly removed for inspection and replacement. It is suitable for high-altitude working environments of the surge arrester body 3 and has the characteristics of convenient installation and later maintenance. It can be used quickly in the early construction and later regular maintenance of DC microgrids.

[0021] like Figure 2 The following describes the specific structure of the card connector 4: Furthermore, the conductive component 402 is a circular ring structure, which is sleeved on the grounding terminal 302 and is concentrically arranged with the grounding terminal 302, and a gap is provided between the inner side of the conductive component 402 and the grounding terminal 302. The lower snap-fit ​​assembly 4 also includes a conductive sheet 403 connected to the inner side of the conductive component 402. The conductive sheet 403 is located in the gap between the conductive component 402 and the grounding terminal 302, and the conductive sheet 403 abuts against the grounding terminal 302.

[0022] Since the grounding terminal 302 is placed inside the snap-fit ​​assembly 4 by plugging it in, in order for the grounding terminal 302 to cooperate properly with the conductive component 402, the conductive component 402 must be in a gap fit with the grounding terminal 302. That is, the inner diameter of the conductive component 402 is larger than the diameter of the grounding terminal 302. However, the gap fit will cause the conductivity of the conductive component 402 to decrease. Therefore, in order to facilitate the insertion of the grounding terminal 302 while enabling the conductive component 402 to conduct electricity normally, a conductive sheet 403 is provided in the gap between the conductive component 402 and the grounding terminal 302. The conductive sheet 403 is an elastic metal sheet, which remains in contact with the grounding terminal 302 under its elastic force, thereby improving the conductivity of the conductive component 402.

[0023] Specifically, the conductive sheet 403 has a "U"-shaped structure, and its opening can be set facing upward or downward. One side of it is connected to the inner side of the conductive component 402, and the other side abuts against the grounding terminal 302. A first elastic element 404 is provided in the opening of the conductive sheet 403. The first elastic element 404 is in a compressed state. The first elastic element 404 can be a metal spring sheet, spring, or other components. Its purpose is to tension the conductive sheet 403 so that both sides of the conductive sheet 403 are always in an open tendency, so that the side of the conductive sheet 403 is always in contact with the grounding terminal 302. The two ends of the first elastic element 404 are respectively fixedly connected to the two inner sides of the conductive sheet 403, which can be done by welding.

[0024] The opening of the conductive sheet 403 is preferably facing downwards, which facilitates the insertion of the grounding terminal 302.

[0025] Specifically, such as Figure 4 As shown, multiple conductive sheets 403 are evenly distributed around the high-voltage end 303 in the circumference, and the contact of multiple conductive sheets 403 can significantly improve the conductivity.

[0026] In addition, one side of the conductive sheet 403 can be fixed to the inner side of the conductive component 402 by screws.

[0027] Furthermore, the conductive component 402 has a circular ring structure, which is sleeved on the grounding end 302. The grounding end 302 is threadedly connected to the lower nut, and the top of the conductive component 402 abuts against the lower nut. The lower snap-fit ​​assembly 4 also includes a lower insulating shell 401, which is connected to the bottom of the insulating plate 2. The lower insulating shell 401 has a hollow structure. The grounding end 302 passes through the insulating plate 2 and is located inside the lower insulating shell 401. The bottom of the lower insulating shell 401 is connected to a fixing base 405. The top of the fixing base 405 supports the bottom of the conductive component 402. A through hole is provided on the side of the lower insulating shell 401, and the grounding wire 7 is connected to the conductive component 402 through the through hole.

[0028] The lower insulating shell 401 can be connected to the bottom of the insulating plate 2 by screws or fixing. The lower nut on the grounding terminal 302 is pre-installed on the surge arrester body 3 on the ground. The insulating shell 401 can be provided with an upward-facing cavity to reduce weight.

[0029] The through hole can be a vertically distributed strip-shaped hole structure. The conductive component 402 is connected to the side of the connector 407. The connector 407 extends out from the through hole and is connected to the grounding wire 7. The connector 407 can be a bolt, threadedly connected to the side of the conductive component 402. It can be connected to the grounding wire 7 through a cable connector. Since the height of the lower nut is not fixed, the strip-shaped hole structure of the through hole can be adapted to the height of the conductive component 402.

[0030] Furthermore, an insulating sleeve 406 is fixedly connected to the top of the fixing base 405, the insulating sleeve 406 is threadedly connected to the grounding terminal 302, the top of the insulating sleeve 406 abuts against the bottom of the conductive component 402, and a limiting part is provided on the lower peripheral surface of the fixing base 405, the limiting part abuts against the bottom of the lower insulating shell 401.

[0031] A handle can be provided at the bottom of the fixed base 405 for easy operation. The limiting part can be ring-shaped and set around the fixed base 405 to limit the position. In specific implementation, after the grounding end 302 is inserted into the lower insulating shell 401, the fixed base 405 is tightened so that the insulating sleeve 406 is threaded to the grounding end 302, thereby fixing the grounding end 302 in place. At this time, the conductive part 402 abuts against the bottom of the lower nut, which can further improve its conductivity.

[0032] In addition, a circular hole 202 is provided on the insulating plate 2. The circular hole 202 is adapted to the lower nut. The lower nut and the grounding end 302 pass through the circular hole 202 downwards. A support part 301 is fixedly provided at the bottom of the surge arrester body 3. The support part 301 is larger than the circular hole 202 and abuts against the upper end face of the insulating plate 2. A positioning ring 203 can also be provided on the insulating plate 2. The positioning ring 203 is concentric with the circular hole 202 and its inner diameter is larger than the diameter of the circular hole 202. The support part 301 is just locked in the positioning ring 203, making the whole structure more stable.

[0033] like Figure 3 The specific structure of the upper connector component 5 is described below: Furthermore, the upper snap-fit ​​assembly 5 includes an upper insulating shell 501, which is a hollow structure and is threadedly connected to the high-voltage end 303. The top of the upper insulating shell 501 is connected to the lightning protection component 6, and the bottom of the lightning protection component 6 abuts against the high-voltage end 303.

[0034] In practice, the upper insulating shell 501 and the lightning arrester component 6 are removed by rotating the upper insulating shell 501, so that the upper snap-fit ​​assembly 5 is detached from the lightning arrester body 3.

[0035] Furthermore, the hollow portion of the upper insulating shell 501 has a stepped hole structure, and an annular cavity is formed between the upper inner surface of the upper insulating shell 501 and the peripheral surface of the high voltage end 303. An annular protrusion is provided on the lower peripheral surface of the lightning protection component 6, and the annular protrusion is located in the annular cavity. The top of the upper insulating shell 501 is connected to an annular cover plate 502, and the lightning protection component 6 passes through the annular cover plate 502. A second elastic element 503 is provided between the top of the annular protrusion and the bottom of the annular cover plate 502.

[0036] The annular protrusion is ring-shaped and arranged around the circumference of the lightning protection component 6. The annular cover plate 502 is provided with a hole for the lightning protection component 6 to pass through. The annular cover plate 502 can be connected to the upper insulating shell 501 by screws. The stepped hole structure of the upper insulating shell 501 includes a large diameter part and a small diameter part. The small diameter part is located at the bottom and is adapted to the high voltage end 303. The large diameter part is located at the top. The inner side of the large diameter part forms an annular cavity with the high voltage end 303. The function of the second elastic member 503 is to press the lightning protection component 6 downward so that the lightning protection component 6 is in close contact with the high voltage end 303. The side of the annular cover plate 502 extending from the top of the lightning protection component 6 is connected to the wire 8. The wire 8 can be connected by a connector 601. The connector 601 can be a bolt or screw connected to the side of the lightning protection component 6 and connected to the wire 8 through a cable connector.

[0037] Furthermore, the bottom of the lightning protection component 6 is provided with a blind hole, which is fitted onto the top of the high-voltage end 303 through the blind hole. The top of the lightning protection component 6 is fixedly connected to the lightning rod. The structure of the blind hole can make the lightning protection component 6 and the high-voltage end 303 more closely contacted. The lightning rod is existing technology and can attract lightning, thereby preventing lightning from directly hitting the power lines near the power grid support component 1.

[0038] During maintenance, the operator first rotates the upper insulating shell 501 to remove the lightning arrester component 6 and the upper snap-fit ​​assembly 5 from the arrester body 3. Then, by rotating the fixing base 405, the restriction on the grounding terminal 302 can be released, allowing the arrester body 3 to be removed. During disassembly, the insulation provided by the upper insulating shell 501, the lower insulating shell 401, and the insulating sleeve 406 prevents the operator from contacting conductive parts, namely the high-voltage terminal 303 and the grounding terminal 302. Thus, the present invention can also protect the operator during implementation, preventing factors such as leakage from endangering the operator's safety.

[0039] In addition, the above-mentioned insulating components can be made of materials such as plastic, wood, and ceramic, and the insulating sleeve 406 is preferably made of plastic.

[0040] The present invention also includes a protection method for DC microgrid equipment, the method comprising: Step 1: Insert the grounding terminal 302 at the bottom of the surge arrester body 3 into the lower snap-fit ​​assembly 4 on the insulating plate 2, and insert the high voltage terminal 303 at the top of the surge arrester body 3 into the upper snap-fit ​​assembly 5. Step 2: The grounding terminal 302 is connected to the grounding wire 7 through the conductive part 402 of the lower snap-fit ​​assembly 4; Step 3: The high-voltage end 303 is connected to the high-voltage busbar through the lightning protection component 6 of the upper clamping assembly 5; Step 4: During maintenance, first remove the upper snap-fit ​​assembly 5 to disconnect the surge arrester component 6 from the high-voltage end 303, and then remove the surge arrester body 3 to disconnect the grounding end 302 from the conductive component 402.

[0041] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, alterations, substitutions, or variations made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A protection device for DC microgrid equipment, comprising a surge arrester body (3), wherein the surge arrester body (3) is located on an insulating plate (2), characterized in that: The insulating plate (2) is equipped with a lower snap-fit ​​assembly (4), the grounding terminal (302) at the bottom of the surge arrester body (3) is inserted into the lower snap-fit ​​assembly (4), and the high voltage terminal (303) at the top of the surge arrester body (3) is inserted into the upper snap-fit ​​assembly (5). The lower snap-fit ​​assembly (4) includes a conductive component (402), which is connected to a grounding wire (7) and is in contact with the grounding terminal (302). The upper snap-fit ​​assembly (5) is provided with a lightning protection component (6), the lightning protection component (6) is connected to the high voltage bus, and the lightning protection component (6) is in contact with the high voltage end (303); The conductive component (402) has a circular ring structure and is sleeved on the grounding terminal (302). A gap is provided between the inner side of the conductive component (402) and the grounding terminal (302). The lower snap-fit ​​assembly (4) further includes a conductive sheet (403) connected to the inner side of the conductive component (402), and the conductive sheet (403) abuts against the grounding terminal (302). The conductive component (402) is a ring structure, which is sleeved on the grounding end (302). The grounding end (302) is threadedly connected to the lower nut, and the top of the conductive component (402) abuts against the lower nut. The lower snap-fit ​​assembly (4) also includes a lower insulating shell (401), which is connected to the bottom of the insulating plate (2). The lower insulating shell (401) is a hollow structure. The grounding end (302) passes through the insulating plate (2) and is located inside the lower insulating shell (401). The bottom of the lower insulating shell (401) is connected to a fixing seat (405). The top of the fixing seat (405) supports the bottom of the conductive component (402). The side of the lower insulating shell (401) is provided with a through hole. The grounding wire (7) is connected to the conductive component (402) through the through hole. The upper snap-fit ​​assembly (5) includes an upper insulating shell (501), which is a hollow structure and is threaded to the high voltage end (303). The top of the upper insulating shell (501) is connected to the lightning protection component (6), and the bottom of the lightning protection component (6) abuts against the high voltage end (303).

2. The DC microgrid equipment protection device according to claim 1, characterized in that: The conductive sheet (403) has a "U" shaped structure, with one side connected to the inner side of the conductive component (402) and the other side abutting the grounding terminal (302). A first elastic element (404) is provided in the opening of the conductive sheet (403), and the first elastic element (404) is in a compressed state.

3. The DC microgrid equipment protection device according to claim 2, characterized in that: The conductive sheets (403) are distributed circumferentially around the high voltage end (303).

4. The DC microgrid equipment protection device according to claim 1, characterized in that: An insulating sleeve (406) is fixedly connected to the top of the fixed base (405). The insulating sleeve (406) is threadedly connected to the grounding terminal (302). The top of the insulating sleeve (406) abuts against the bottom of the conductive component (402). A limiting part is provided on the lower circumferential surface of the fixed base (405). The limiting part abuts against the bottom of the lower insulating shell (401).

5. A DC microgrid equipment protection device according to claim 1, characterized in that: The hollow portion of the upper insulating shell (501) has a stepped hole structure. An annular cavity is formed between the upper inner side of the upper insulating shell (501) and the circumferential surface of the high voltage end (303). An annular protrusion is provided on the lower circumferential surface of the lightning protection component (6). The annular protrusion is located in the annular cavity. The top of the upper insulating shell (501) is connected to an annular cover plate (502). The lightning protection component (6) passes through the annular cover plate (502). A second elastic element (503) is provided between the top of the annular protrusion and the bottom of the annular cover plate (502).

6. The DC microgrid equipment protection device according to claim 1, characterized in that: The lightning protection component (6) has a blind hole at its bottom, which is fitted onto the top of the high voltage end (303) through the blind hole. The top of the lightning protection component (6) is fixedly connected to a lightning rod.

7. A method for protecting DC microgrid equipment, applied to the protection device as described in any one of claims 1-6, characterized in that, The method includes: Insert the grounding terminal (302) at the bottom of the surge arrester body (3) into the lower snap-fit ​​assembly (4) on the insulating plate (2), and insert the high voltage terminal (303) at the top of the surge arrester body (3) into the upper snap-fit ​​assembly (5); The grounding terminal (302) is connected to the grounding wire (7) through the conductive part (402) of the lower snap-fit ​​assembly (4); The high-voltage end (303) is connected to the high-voltage busbar through the lightning protection component (6) of the upper snap-fit ​​assembly (5); During maintenance, first remove the upper snap-fit ​​assembly (5) to disconnect the surge arrester component (6) from the high voltage end (303), and then remove the surge arrester body (3) to disconnect the grounding end (302) from the conductive component (402).

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