Lightning arrester for power transmission line

Abstract

The utility model relates to a lightning arrester for a power transmission line, which comprises a lightning arrester body, a first end of which is connected to a tower to be grounded; the first discharge gap is connected with the lightning arrester body in series, the first discharge gap comprises a gap insulator, and a first end of the gap insulator and a second end of the lightning arrester body are assembled together and electrically connected to the second end of the lightning arrester body; the lightning arrester electrode is arranged at the second end of the gap insulator and electrically connected with the second end of the gap insulator, a second discharge gap is formed between the lightning arrester electrode and an arc striking electrode installed on the protected element, one end of the protected element is electrically connected to the tower, the other end of the protected element is electrically connected to the power transmission line, and the protected element is provided with the arc striking electrode; one end of the separating device is connected to the first end of the gap insulator, the other end of the separating device is connected to the second end of the gap insulator so as to bypass the first discharge gap, and the separating device is disconnected in response to a fault of the lightning arrester body so as to be connected to the first discharge gap.

Description

Technical Field

[0001] The utility model relates to the technical field of transmission line protection, specifically to a lightning arrester for transmission lines, and more specifically to an external gap line lightning arrester. Background Art

[0002] The external gap line lightning arrester can provide a discharge channel for external energy such as lightning energy, and ensure that the voltage across both ends of a protected component (such as a line insulator) does not exceed the flashover voltage, thereby ensuring that the line does not trip.

[0003] The external gap line lightning arrester has a gap connected in series externally, usually an air gap. The air gap is non-conductive under normal operating voltage to isolate the lightning arrester body and prevent current from passing through. However, when the voltage exceeds a certain specific value (such as lightning overvoltage or switching overvoltage), the air gap will be broken down, resulting in discharge, thereby limiting the overvoltage and protecting electrical equipment from damage.

[0004] However, traditional external gap line lightning arresters still have some drawbacks. One of them is that after suffering from overvoltage and causing damage to the non-linear metal oxide resistor chips that make up the lightning arrester body, their performance in withstanding switching overvoltage and power frequency overvoltage drops significantly. This means that once the non-linear metal oxide resistor chips are damaged, the protection ability of the line lightning arrester will be affected, thereby increasing the risk of the transmission line system being damaged by overvoltage.

[0005] In addition, traditional external gap line lightning arresters also require external detection devices to detect whether the non-linear metal oxide resistor chips are damaged, which increases the complexity of the system and the maintenance cost.

[0006] Currently, there is no effective solution to solve the problem that the performance of the lightning arrester in withstanding switching overvoltage and power frequency transient overvoltage drops significantly after the lightning arrester body is damaged. Moreover, for the detection of the damage of the lightning arrester body in the transmission line, methods such as observing the appearance and using professional fault monitoring equipment for detection are used, which will have problems such as inaccurate detection, labor-consuming, complex system, and high maintenance cost.

[0007] Therefore, in view of the certain drawbacks of traditional external gap line lightning arresters in practical applications, it is necessary to seek a more optimized alternative solution to improve the ability of the transmission line system to withstand overvoltage damage. Summary of the Utility Model

[0008] This application provides a lightning arrester for transmission lines to at least solve the problems in the prior art that the performance of the lightning arrester in withstanding switching overvoltage and power frequency transient overvoltage drops significantly after the lightning arrester body is damaged, as well as the technical problems of inaccurate detection, labor-consuming, complex system, and high maintenance cost for the detection of the damage of the lightning arrester body in the transmission line.

[0009] According to one aspect of the embodiments of the present application, there is provided a lightning arrester for a transmission line, including a lightning arrester body having a first end and a second end, the first end being connected to a pole tower for grounding; a first discharge gap connected in series with the lightning arrester body, the first discharge gap including a gap insulator having a first end and a second end, the first end of the gap insulator being assembled with the second end of the lightning arrester body and electrically connected to the second end of the lightning arrester body; a lightning arrester electrode provided at the second end of the gap insulator and electrically connected to the second end of the gap insulator, a second discharge gap being formed between the lightning arrester electrode and an arc-leading electrode mounted on a protected component, the second discharge gap being an air gap, wherein one end of the protected component is electrically connected to the pole tower for grounding and the other end of the protected component is electrically connected to the transmission line and provided with an arc-leading electrode; and a disconnector, one end of the disconnector being connected to the first end of the gap insulator and the other end of the disconnector being connected to the second end of the gap insulator to bypass the first discharge gap, wherein the disconnector disconnects in response to a fault of the lightning arrester body to access the first discharge gap.

[0010] In this way, in addition to having an air discharge gap outside the lightning arrester body, the lightning arrester of the present disclosure also has a series insulator support gap, that is, the air discharge gap and the insulator support gap act together. In addition, the two sides of the insulator support gap are connected by a disconnector. When the lightning arrester body is not damaged, the disconnector is normal and the gap insulator between the insulator support gaps is short-circuited, which can ensure good lightning overvoltage protection characteristics of the lightning arrester. When the lightning arrester body is damaged by overvoltage, the disconnector disconnects and the gap insulator between the insulator support gaps is accessed. At this time, the insulation gap of the lightning arrester becomes the air discharge gap + the insulator support gap. The increase in the insulation gap enables the lightning arrester to withstand higher switching overvoltages and power frequency transient overvoltages. Moreover, by increasing the insulator support gap, the performance of the lightning arrester in withstanding switching overvoltages and power frequency transient overvoltages is improved. Therefore, the air gap value can be set relatively small, which has a better protective effect on the protected components (such as insulators) on the transmission line, thereby improving the protection characteristics of the lightning arrester for the system when the lightning arrester body is not damaged.

[0011] According to an exemplary embodiment of the present application, the disconnector is a visual fault indicator indicating the operating state of the lightning arrester body.

[0012] According to an exemplary embodiment of the present application, the disconnector includes a disconnector and a cable. One end of the disconnector is connected to the first end of the gap insulator or the second end of the lightning arrester body through the cable, and the other end of the disconnector is connected to the second end of the gap insulator. In response to a fault of the lightning arrester body, the other end of the disconnector disengages from the second end of the gap insulator and hangs down from the second end of the lightning arrester body.

[0013] According to an exemplary embodiment of the present application, the state that the disconnector hangs down from the second end of the arrester body indicates that the arrester body has failed.

[0014] In this way, it is possible to indicate whether the arrester body is damaged by observing the state of the disconnection device. For example, when the disconnector in the disconnection device hangs down from the second end of the arrester body, this state can indicate that the arrester body has failed. When the disconnector in the disconnection device is connected to both ends of the gap insulator, this state can indicate that the arrester body is working normally.

[0015] According to an exemplary embodiment of the present application, the disconnector is a thermal explosion type disconnector or a thermal melting type disconnector.

[0016] In this way, when the arrester body fails, the disconnector can quickly disconnect from the second end of the gap insulator, that is, the first gap starts to act, so that the line can withstand higher switching overvoltages and power frequency overvoltages.

[0017] According to an exemplary embodiment of the present application, a first fitting connected to the arrester body is provided at the first end of the gap insulator, and a second fitting connected to the arrester electrode is provided at the second end of the gap insulator.

[0018] In this way, a discharge gap can be realized with a simple structure.

[0019] According to an exemplary embodiment of the present application, the arrester body includes a plurality of arrester units connected in series, and each arrester unit includes a plurality of non-linear metal oxide resistor chips connected in series.

[0020] In this way, the arrester body can be constructed according to the voltage levels used in different scenarios, different countries, etc., so as to protect lines of different voltage levels.

[0021] According to an exemplary embodiment of the present application, the protected element includes a line insulator, and the line insulator is connected in parallel with the arrester between the tower and the transmission line.

[0022] According to an exemplary embodiment of the present application, an insulating base is installed at the first end of the arrester body, and the insulating base is fixed to the tower by bolts.

[0023] According to an exemplary embodiment of the present application, the arrester electrode is capable of telescoping to adjust the gap length of the second discharge gap.

[0024] In this way, the second discharge gap can be finely adjusted according to the different lengths of the line insulators in actual use and the different switching overvoltages of the power transmission system to protect the line insulators from damage.

[0025] In an embodiment of the present application, a lightning arrester for a transmission line is provided. The lightning arrester for the transmission line improves the performance of the lightning arrester in withstanding switching overvoltage and power frequency transient overvoltage, and can set the air gap value relatively small, so as to have a better protective effect on the protected components (such as insulators) on the transmission line, thereby improving the protection characteristics of the lightning arrester for the system when the lightning arrester body is not damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments and descriptions thereof of the present application are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0027] FIG. 1 is a simplified schematic diagram of a lightning arrester for a transmission line according to an embodiment of the present application.

[0028] FIG. 2 is a simplified schematic diagram showing the situation of a lightning arrester body failure in a lightning arrester for a transmission line according to an embodiment of the present application.

[0029] DESCRIPTION OF THE REFERENCE NUMERALS IN THE DRAWINGS:

[0030] 10: Lightning arrester for a transmission line;

[0031] 1: Lightning arrester body;

[0032] 2: First discharge gap;

[0033] 3: Lightning arrester electrode;

[0034] 4: Disconnector

[0035] 5: Tower:

[0036] 6: Second discharge gap;

[0037] P: Protected component. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0039] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0040] As discussed in the background art above, after the traditional external gap line arrester suffers from overvoltage and the non-linear metal oxide resistor chips that make up the arrester body are damaged, its performance in withstanding switching overvoltage and power frequency overvoltage drops significantly. This means that once the non-linear metal oxide resistor chips are damaged, the protection ability of the line arrester will be affected, thus increasing the risk of the transmission line system being damaged by overvoltage. In addition, the traditional external gap line arrester also requires an external detection device to detect whether the non-linear metal oxide resistor chips are damaged, which increases the complexity and maintenance cost of the system.

[0041] For this reason, the concept of the present utility model is that in addition to a series air discharge gap outside the arrester body, an insulator support gap is also connected in series, and a disconnection device is used to connect both sides of the insulator support gap. When the arrester body is not damaged, the disconnection device is normal, and the insulator between the insulator support gaps is short-circuited, which can ensure good overvoltage protection characteristics of the line arrester. When the arrester body suffers from overvoltage damage, the disconnection device disconnects, and the insulator between the insulator support gaps starts to work. At this time, the insulation gap of the line arrester changes from only the air discharge gap to the air discharge gap + the insulator support gap. The increase in the insulation gap enables the line arrester to withstand higher switching overvoltage and power frequency transient overvoltage, improving the performance of the arrester in withstanding switching overvoltage and power frequency transient overvoltage. In addition, based on this structure, the air gap value can be set relatively small, so as to have a better protective effect on the protected components (such as insulators) on the transmission line, thereby improving the protection characteristics of the arrester for the system when the arrester body is not damaged. At the same time, the state of the disconnection device can be observed to indicate whether the arrester body is damaged.

[0042] Figure 1 is a simplified schematic diagram of an arrester for a transmission line according to an embodiment of the present application. As shown in Figure 1, the arrester 10 for a transmission line includes: an arrester body 1, a first discharge gap 2, an arrester electrode 3, and a disconnection device 4.

[0043] In this embodiment, the arrester body 1 includes a plurality of arrester units connected in series. As shown in FIG. 1, the arrester body 1 includes a first arrester unit 11 and a second arrester unit 12. Both the first arrester unit 11 and the second arrester unit 12 include a plurality of non-linear metal oxide resistor chips connected in series. The first arrester unit 11 and the second arrester unit 12 may have different models or the same model.

[0044] Specifically, the arrester body 1 has a first end 1A and a second end 1B. The first end 1A of the arrester body 1 is connected to the pole tower 5 for grounding. That is, the first end 1A is the low-voltage end and the second end 1B is the high-voltage end to be connected to the transmission line. In detail, the connecting fitting of the first end 1A of the arrester body 1 is electrically connected to the pole tower 5 to ground the arrester body 1. As an example, an insulating base 7 may be installed at the first end 1A of the arrester body 1, and the insulating base 7 may be fixed to the pole tower 5 by bolts.

[0045] The first discharge gap 2 is connected in series with the arrester body 1. Specifically, the first discharge gap 2 may be an insulator support gap and may include a gap insulator 21. The gap insulator 21 has a first end 21A and a second end 21B. The first end 21A of the gap insulator 21 is assembled with the second end 1B of the arrester body 1 and is electrically connected to the second end 1B of the arrester body 1. That is, the first end 21A of the gap insulator 21 is the low-voltage end, and the second end 21B of the gap insulator 21 is the high-voltage end.

[0046] The arrester electrode 3 is disposed at the second end 21B of the gap insulator 21 and is electrically connected to the second end 21B of the gap insulator 21. A second discharge gap 6 is formed between the arrester electrode 3 and the arcing electrode PA installed on the protected element P. The second discharge gap 6 is an air gap. One end of the protected element P may be electrically connected to the pole tower 5 for grounding, and the other end of the protected element P is electrically connected to the transmission line and is provided with the arcing electrode PA. In this embodiment, as shown in FIG. 1, the protected element P is a line insulator, and the line insulator is connected in parallel with the arrester 10 between the pole tower 5 and the transmission line.

[0047] In this embodiment, the arrester electrode 3 is telescopic to adjust the gap length of the second discharge gap 6. As shown in FIG. 1, in this embodiment, the arrester electrode 3 may include a metal strip with holes and a support strip for supporting the metal strip. A snap button for cooperating with the holes on the metal strip to fix the metal strip may be provided on the support strip. In practice, the extending length of the metal strip can be changed by moving the metal strip.

[0048] One end of the disconnecting device 4 can be connected to the first end 21A of the gap insulator 21, and the other end of the disconnecting device 4 can be connected to the second end 21B of the gap insulator 21 to bypass the first discharge gap 2. Wherein, the disconnecting device 4 can be disconnected in response to a fault of the arrester body 1 to connect the first discharge gap 2.

[0049] Specifically, as shown in FIG. 1, the disconnecting device 4 is connected to both sides of the first discharge gap 2. When the arrester body 1 is not damaged, the disconnecting device 4 is normal. Therefore, the gap insulator 21 between the first discharge gaps 2 is short-circuited, that is, bypassed, thereby ensuring good overvoltage protection characteristics of the line arrester. When the arrester body 1 is damaged by overvoltage, as shown in FIG. 2, the disconnecting device 4 is damaged, and the gap insulator 21 is connected and starts to work. At this time, the insulating gap of the arrester changes from only the second discharge gap 6 to the second discharge gap 6 + the first discharge gap 2. The increase in the insulating gap enables the arrester to withstand higher switching overvoltage and power frequency transient overvoltage.

[0050] In addition, the state of the disconnecting device 4 can be observed to indicate whether the arrester body is damaged. In other words, in this embodiment, the disconnecting device 4 can be a visual fault indicator for indicating the operating state of the arrester body 1.

[0051] Specifically, the disconnecting device 4 can include a disconnector 41 and a cable 42. One end of the disconnector 41 is connected to the first end 21A of the gap insulator 21 or the second end 1B of the arrester body 1 through the cable 42, and the other end of the disconnecting device 4 is connected to the second end 21B of the gap insulator 21. In response to a fault of the arrester body 1, the other end of the disconnector 4 is disconnected from the second end 21B of the gap insulator 21 and hangs down from the second end 1B of the arrester body 1. The state where the disconnector 41 hangs down from the second end 1B of the arrester body 1 can indicate that the arrester body 1 has a fault.

[0052] Optionally, the cable 42 can be replaced with a conductive rod, and the above-mentioned visual fault indication function and effect can also be achieved.

[0053] In this embodiment, the disconnector 41 can be a thermal explosion type disconnector or a thermal melting type disconnector. The disconnector of the present disclosure is not limited to the above types of disconnectors, as long as the disconnector 21 can quickly disconnect from the second end 21B of the gap insulator 21 before the protected element P flashes over when the arrester body 1 fails.

[0054] More specifically, the first end 21A of the gap insulator 21 is provided with a first fitting connected to the arrester body 1, and the second end 21B of the gap insulator 21 is provided with a second fitting connected to the arrester electrode 3.

[0055] The above are specific embodiments of the lightning arrester for transmission lines of the present disclosure. In addition to an external series air gap, the lightning arrester of the present disclosure is also serially connected with an insulator support gap, and the air gap and the insulator support gap are serially connected. When the lightning arrester body operates normally, only the air gap operates and the insulator support gap is not connected. When the lightning arrester body fails, the insulator support gap is connected in series with the air gap to thereby increase the insulation gap length, so that the lightning arrester can withstand higher switching overvoltages and power frequency transient overvoltages, thus protecting the protected components from being damaged.

[0056] The lightning arrester of the present disclosure is not limited to the structure shown in the above embodiments. The structures of the lightning arresters related to the inventive concept of the present disclosure are all within the protection scope of the present disclosure.

[0057] The lightning arrester for transmission lines according to the embodiments of the present application has at least the following advantages over the prior art:

[0058] 1. Since the lightning arrester of the present disclosure increases the insulator support gap, when the lightning arrester body is damaged, the insulation gap of the lightning arrester becomes the air gap plus the insulator support gap. Therefore, compared with traditional lightning arresters, the lightning arrester of the present disclosure can withstand higher switching overvoltages and power frequency transient overvoltages.

[0059] 2. The lightning arrester of the present disclosure is provided with a disconnection device. When the overvoltage causes the lightning arrester body to be damaged, the disconnector in the disconnection device is automatically damaged. Therefore, the state of the disconnector can be observed to determine whether the lightning arrester body is damaged.

[0060] 3. The lightning arrester of the present disclosure improves the performance of withstanding switching overvoltages and power frequency transient overvoltages by increasing the insulator support gap. Therefore, the gap value of the air gap can be designed to be relatively small, thus having a better protective effect on the insulators of the transmission line.

[0061] In the above embodiments of the present application, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0062] In the several embodiments provided by the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the above-described device embodiments are merely illustrative. The above is only the preferred embodiment of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A lightning arrester for a power transmission line, characterized in that: The lightning arrester comprises: A lightning arrester body (1) having a first end and a second end, wherein the first end is connected to a pole tower (5) for grounding; a first discharge gap (2) connected in series with the arrester body (1), the first discharge gap (2) comprising a gap insulator (21), the gap insulator (21) having a first end and a second end, the first end of the gap insulator (21) being assembled with the second end of the arrester body (1) and electrically connected to the second end of the arrester body (1); an arrester electrode (3) arranged at the second end of the gap insulator (21) and electrically connected to the second end of the gap insulator (21), a second discharge gap (6) being formed between the arrester electrode (3) and an arc-striking electrode mounted on the protected element (P), the second discharge gap (6) being an air gap, wherein one end of the protected element (P) is connected to the pole tower (5) for grounding, and the other end of the protected element (P) is connected to the transmission line and is provided with the arc-striking electrode; and A disconnecting device (4), one end of the disconnecting device (4) is connected to the first end of the gap insulator (21) and the other end of the disconnecting device (4) is connected to the second end of the gap insulator (21) to bypass the first discharge gap (2), wherein the disconnecting device (4) is disconnected in response to a fault of the arrester body (1) to access the first discharge gap (2).

2. The lightning arrester for power transmission lines according to claim 1, characterized in that: The disconnecting device (4) is a visual fault indicator indicating the operating state of the arrester body (1).

3. The lightning arrester for power transmission lines according to claim 1, characterized in that: The disconnector (4) comprises a disconnector (41) and a cable (42), one end of the disconnector (41) being connected to the first end of the gap insulator (21) or the second end of the arrester body (1) via the cable (42), and the other end of the disconnector (41) being connected to the second end of the gap insulator (21), and in response to a fault of the arrester body (1), the other end of the disconnector (41) is disconnected from the second end of the gap insulator (21) to hang down from the second end of the arrester body (1).

4. The lightning arrester for power transmission lines according to claim 3, characterized in that: The state in which the disconnector (41) hangs down from the second end of the arrester body (1) indicates that a fault has occurred in the arrester body (1).

5. The lightning arrester for power transmission lines according to claim 3, characterized in that: The disconnector (41) is a thermal explosion disconnector or a hot melt disconnector.

6. The lightning arrester for power transmission lines according to claim 1, characterized in that: The first end of the gap insulator (21) is provided with a first hardware fitting connected to the arrester body (1), and the second end of the gap insulator (21) is provided with a second hardware fitting connected to the arrester electrode (3).

7. The lightning arrester for power transmission lines according to claim 1, characterized in that: The arrester body (1) comprises a plurality of arrester units connected in series, and each arrester unit comprises a plurality of nonlinear metal oxide resistors connected in series.

8. The lightning arrester for power transmission lines according to claim 1, characterized in that: The protected element (P) comprises a line insulator, and the line insulator is connected in parallel with the lightning arrester between the tower (5) and the transmission line.

9. The lightning arrester for power transmission lines according to claim 1, characterized in that: An insulating base (7) is installed on the first end of the arrester body (1), and the insulating base (7) is fixed to the pole tower (5) by means of bolts.

10. The lightning arrester for power transmission lines according to claim 1, characterized in that: The arrester electrode (3) is retractable to adjust the gap length of the second discharge gap (6).

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