Lightning arrester with pressure relief device

Abstract

The invention discloses a lightning arrester with a pressure relief device. The lightning arrester comprises an insulating jacket, a zinc oxide resistor disc, an upper terminal electrode and a lower terminal electrode, the upper terminal electrode is connected with a power grid cable, and the lower terminal electrode is connected with a ground wire. An annular cavity is arranged in a lower end cover of the insulating jacket, elastic filler and a plastic hoop with an opening and an inclined plane are arranged in the cavity, and a pressure relief ring opening directly communicated with the outside is arranged at the bottom of the lower end cover. In a normal state, the plastic hoop is kept above the pressure relief ring opening by the elastic filler to seal the pressure relief ring opening; during pressure relief, high-pressure gas passes through the inclined plane to enable the plastic hoop to compress the elastic filler and open the elastic filler, and the gas is released from the pressure relief ring opening. According to the design, high-speed fragments are effectively avoided, potential safety hazards are reduced, the safety of personnel and equipment is guaranteed, the structure is reasonable and compact, and the overall performance of the lightning arrester is not affected.

Description

Technical Field

[0001] The invention relates to the field of lightning arresters, and in particular to a lightning arrester with a pressure relief device. Background Art

[0002] Lightning arresters are also called overvoltage protectors or overvoltage limiters. Lightning arresters are generally connected between the power grid cable and the earth, usually in parallel with the protected equipment. Lightning arresters can effectively protect equipment. Once abnormal voltage occurs, the lightning arrester will take action and play a protective role. When the equipment is running under normal operating voltage, the lightning arrester will not take effect and it will be regarded as a circuit breaker to the ground. Once high voltage appears and endangers the insulation of the protected equipment, the lightning arrester will immediately act to direct the high voltage impact current to the earth, thereby limiting the voltage amplitude and protecting the equipment. When the overvoltage disappears, the lightning arrester quickly returns to its original state, allowing the equipment and lines to work normally.

[0003] The zinc oxide resistors in the commonly used zinc oxide arresters have good nonlinear volt-ampere characteristics. When the normal operating voltage is applied to the arrester, only a small leakage current flows through the resistor, which is equivalent to an open circuit. When an overvoltage occurs, a large current flows through the arrester, but the voltage is limited to a certain range, close to a short circuit.

[0004] The zinc oxide arrester is composed of multiple zinc oxide resistors stacked inside and an insulating jacket outside. Terminal electrodes are connected to both ends of the zinc oxide resistor, the upper terminal electrode is connected to the grid conductor, and the lower terminal electrode is connected to the ground wire.

[0005] When the voltage is too high and the zinc oxide resistor is damaged, high temperature and high pressure arc gas will be generated inside the arrester. In the prior art, a thin wall portion is provided on the insulating jacket of the arrester to release the pressure, so that the high pressure gas breaks through the thin wall portion and releases the pressure.

[0006] However, the thin wall portion will also reduce the strength of the arrester insulation jacket at this part, causing accidental damage. In addition, the thin wall portion is generally arranged on the circumferential side wall of the arrester, and the high-pressure and high-temperature arc gas leaking out from the side of the arrester may injure personnel and equipment near the arrester.

[0007] To solve the above problems, in the solution provided by patent CN114242359B, a compressed force storage spring is set outside the zinc oxide resistor in the upper part of the insulating jacket, and a telescopic spring and a lock tongue are installed in the lock tongue hole in the middle of the inner wall. When the lock tongue is extended normally, the force storage spring presses the impact block on the upper side of the lock tongue, and a concentric double groove ring with a V-shaped cross section is set on the inner side of the lower end cover. When high-temperature and high-pressure arc gas is generated in the lightning arrester, the high-pressure gas presses the lock tongue into the hole to trigger the force storage spring, so that the impact block pops out and impacts the inner side of the lower end cover, causing the lower end cover to break and fall off along the concentric double groove ring to form a pressure relief ring outlet exhaust. Such a design sets the pressure relief part at its lower end cover, which can minimize the harm of the leaked high-pressure and high-temperature arc gas. At the same time, there is no thin-walled part deliberately set on the lower end cover, but the built-in energy storage spring and impact block are triggered by high-pressure gas to penetrate the pressure relief ring, and the opening groove can be set on the inner wall surface of the lower end cover, which will not affect the external strength of the insulating jacket.

[0008] However, this solution will still produce high-speed fragments when the arrester releases pressure, which still poses a safety hazard. Summary of the invention

[0009] In view of the above-mentioned defects of the prior art, the present invention provides a lightning arrester with a pressure relief device, including an insulating jacket, a zinc oxide resistor, an upper terminal electrode and a lower terminal electrode, the upper terminal electrode is connected to the grid cable, the lower terminal electrode is connected to the grounding wire, an annular chamber is arranged in the lower end cover of the insulating jacket, an elastic filler and a plastic clamp are arranged in the annular chamber, an opening and a slope are arranged on the plastic clamp, and a pressure relief ring opening directly to the outside is arranged at the bottom of the lower end cover. Under normal conditions, the open clamp is held above the pressure relief ring opening by the elastic filler, so that the pressure relief ring opening is closed. When the pressure is relieved, the high-pressure gas generated in the lightning arrester passes through the slope to cause the plastic clamp to compress the elastic filler and expand it into the annular chamber. At this time, the pressure relief ring opening is opened, and the high-temperature and high-pressure arc gas is discharged from here.

[0010] Furthermore, the elastic filler is made of rubber or foam material.

[0011] Compared with previous patents, this invention effectively avoids the generation of high-speed fragments, significantly reduces safety hazards, and ensures the safety of personnel and equipment near the arrester. At the same time, through the unique combination of annular chambers, elastic fillers, plastic clamps and other components, a reliable pressure relief control mechanism is formed. The structural design is reasonable and compact, does not occupy too much extra space, and ensures the overall stability of the arrester.

[0012] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1is a side sectional view of the arrester of the present invention in a normal working state;

[0014] Figure 2 yes Figure 1 AA section view;

[0015] Figure 3 is a side sectional view of the arrester of the present invention in a pressure relief state;

[0016] Figure 4 yes Figure 3 AA section view;

[0017] Figure 5 It is a three-dimensional diagram of the plastic clamp in the present invention. DETAILED DESCRIPTION

[0018] The following describes several preferred embodiments of the present invention with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0019] In the drawings, components with the same structure are indicated by the same numerical reference numerals, and components with similar structures or functions are indicated by similar numerical reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0020] like Figure 1-5 As shown, the arrester with a pressure relief device of the present invention includes an insulating jacket 1, a zinc oxide resistor 2, an upper terminal electrode 3, and a lower terminal electrode 4. Among them, the upper terminal electrode 3 is connected to the grid cable, and the lower terminal electrode 4 is connected to the ground wire. An annular chamber 5 is arranged in the lower end cover 9 of the insulating jacket 1. An elastic filler 8 and a plastic clamp 7 are arranged in the annular chamber 5. An opening 71 and a slope 72 are arranged on the plastic clamp 7. A pressure relief ring 6 that directly passes through the outside is arranged at the bottom of the lower end cover 9. Under normal working conditions, the open clamp 5 is held above the pressure relief ring 6 by the elastic filler 8, so that the pressure relief ring 6 is closed. When the pressure is relieved, the high-pressure gas generated in the arrester passes through the slope 72 to cause the plastic clamp 7 to compress the elastic filler 8 and open it into the annular chamber 5. At this time, the pressure relief ring 6 is opened, and the high-temperature and high-pressure arc gas is released from here.

[0021] The elastic filler can be made of materials such as rubber and foam.

[0022] Compared with previous patents, this invention effectively avoids the generation of high-speed fragments, significantly reduces safety hazards, and ensures the safety of personnel and equipment near the arrester. At the same time, through the unique combination of annular chambers, elastic fillers, plastic clamps and other components, a reliable pressure relief control mechanism is formed. The structural design is reasonable and compact, does not occupy too much extra space, and ensures the overall stability of the arrester.

[0023] The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A lightning arrester with a pressure relief device, characterized in that: The invention comprises an insulating jacket (1), a zinc oxide resistor (2), an upper terminal electrode (3) and a lower terminal electrode (4), wherein the upper terminal electrode (3) is connected to a power grid cable, and the lower terminal electrode (4) is connected to a grounding wire. An annular chamber (5) is arranged in a lower end cover (9) of the insulating jacket (1), and an elastic filler (8) and a plastic clamp (7) are arranged in the annular chamber (5). The plastic clamp (7) is provided with an opening (71) and an inclined surface (72). A pressure relief ring (6) directly connected to the outside is arranged at the bottom. Under normal working conditions, the open clamp (5) is held above the pressure relief ring (6) by the elastic filler (8), so that the pressure relief ring (6) is closed. When the pressure is relieved, the high-pressure gas generated in the arrester passes through the inclined surface (72) to cause the plastic clamp (7) to compress the elastic filler (8) and expand it into the annular chamber (5). At this time, the pressure relief ring (6) is opened, and the high-temperature and high-pressure arc gas is released from here.

2. The arrester with pressure relief device according to claim 1, characterized in that: The elastic filler (8) is made of rubber material.

3. The arrester with pressure relief device according to claim 1, characterized in that: The elastic filler (8) is made of foam material.

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