CN217882301U

CN217882301U - Parallel lightning arrester

Info

Publication number: CN217882301U
Application number: CN202221019605.1U
Authority: CN
Inventors: 陈锡阳; 吴文熠; 陈俊恺; 王晨
Original assignee: Shenzhen Dailu Technology Co ltd
Current assignee: Shenzhen Dailu Technology Co ltd
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-11-22
Anticipated expiration: 2032-04-29

Abstract

The utility model discloses a parallelly connected arrester, its characterized in that includes: the fuse protector comprises arc extinguishing tubes and fuses, the fuses preset fusing capacity and penetrate through electrode parts and connector parts of the arc extinguishing tubes to be electrically connected, the electrode parts of the fuse protectors are electrically connected, and the connector parts are fixedly connected to a tower after being electrically connected; a series gap formed by a difference gap with adjustable distance between the electrode part and the lead; if lightning breaks through the series gap, the fault current is smaller than the parallel fusing capacity of each fuse, the fuses are not fused, and the gap arc is automatically extinguished; if the lightning breaks through the series gap, the fault current is larger than the parallel fusing capacity of each fuse wire, the fuse wires are fused, and the electric arc in the tube is extinguished by the arc extinguishing tube. The utility model discloses can cut off bigger short-circuit current to solve the annex distribution overhead line lightning protection problem of transformer substation.

Description

Parallel lightning arrester

Technical Field

The utility model relates to a high-tension overhead distribution lines lightning protection technical field especially relates to a parallelly connected arrester.

Background

The high-voltage distribution lines in China mainly use 10kV alternating-current voltage, most of the high-voltage distribution lines are overhead lines, and the high-voltage distribution lines are erected by adopting single circuits or multiple circuits, have the span of about 50 meters, and have the total amount of over 400 ten thousand kilometers. In the operation process, the lightning causes tripping and even line breaking accidents frequently, and serious loss is caused to national economy. The overhead insulated conductor is very easily broken wire accident when suffering the thunderbolt, and repair time is long, and the power failure loss is big, and the person is electrocuted the risk height, needs to solve urgently.

A gap with gas-generating arc-extinguishing function can release lightning current when a line is subjected to lightning, an arc extinguishing tube generates gas under arc burning, arcs are extinguished when power frequency crosses zero, lightning trip is avoided, and the lightning protection level of the line is improved. The capacity of the gas generation arc tube manufactured by the prior general process for cutting off the short-circuit current is only 12.5kA generally. With the increase of the short-circuit capacity of the power grid, the short-circuit current of a 10kV overhead line within one kilometer near a transformer substation can reach 20kA, and exceeds the arc extinguishing capability of a common arc extinguishing tube.

In order to ensure the safe and reliable power supply of a power distribution network, a gas production arc extinguishing lightning protection device which has higher arc extinguishing capability and can cut off larger short-circuit current is urgently needed to be researched and developed so as to realize the lightning protection of full coverage of a power distribution overhead line and basically eliminate lightning trip and disconnection.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a parallelly connected arrester realizes higher arc extinguishing ability, cuts off bigger short-circuit current to solve above-mentioned distribution overhead line lightning protection problem.

In order to realize the above purpose, the utility model relates to a parallelly connected arrester is installed in distribution overhead line, a serial communication port, include: the fuse protector comprises arc extinguishing tubes and fuses, wherein the fuses are preset with fusing capacity and penetrate through electrode parts and joint parts of the arc extinguishing tubes to be electrically connected, the electrode parts of the fuse protectors are electrically connected, and the joint parts are fixedly connected to a tower after being electrically connected; a series gap formed by a difference gap with adjustable distance between the electrode part and the lead; if lightning breaks through the series gap, the fault current is smaller than the parallel fusing capacity of each fuse, the fuses are not fused, and the gap arc is automatically extinguished; if the series gap is broken down by thunder, the fault current is larger than the parallel fusing capacity of each fuse, the fuses fuse, and the arc in the tube is extinguished by the arc extinguishing tube.

Compared with the prior art, the utility model relates to a parallelly connected lightning arrester has following beneficial effect: the gas-generating arc-extinguishing lightning protection device has higher arc-extinguishing capability and can cut off larger short-circuit current, is suitable for overhead line sections with particularly large short-circuit current, is safe and reliable, realizes the lightning protection of the full coverage of the distribution overhead line, and basically eliminates lightning trip and disconnection.

Preferably, the arc-extinguishing tube comprises an insulating tube and a gas-generating material layer of a lining, the gas-generating material layer is burned by high temperature of electric arc in the tube to decompose gas and is ejected from the electrode part to form longitudinal quenching, or the joint part is provided with a pressure-releasing cover, and the pressure of the gas is higher than the preset bearing force of the pressure-releasing cover to push the pressure-releasing cover to eject, so that the explosion of the arc-extinguishing tube is avoided.

Preferably, the electrode part is sleeved with an indication cover, the appearance color of the indication cover is different from that of the arc extinguishing tube, and when the fuse is fused, the indication cover is pushed away by high-pressure gas or a compression spring so as to be discovered by inspection.

Preferably, the series gap is adjusted in gap distance by at least one arc starting electrode or the terminal portion so that a volt-second characteristic of the series gap is below a volt-second characteristic of the insulator, the arc starting electrode is composed of a conductor and includes a clamping portion and a discharge electrode, and the clamping portion is clamped on the electrode portion or the lead wire.

Preferably, the lead is an insulated lead, the discharge electrode includes a first discharge electrode extending to the load side of the insulated lead and a second discharge electrode extending to the power supply side of the insulated lead, the first discharge electrode and the electrode portion form a series gap, the second discharge electrode and the joint portion form a backup gap, the volt-second characteristic of the series gap is lower than the volt-second characteristic of the backup gap, the volt-second characteristic of the backup gap is lower than the volt-second characteristic of the insulator, and after the fuse is fused, the backup gap provides a breakdown discharge channel to prevent the insulated lead and the insulator from being ablated by an arc.

Preferably, the series gap is adjusted in distance, so that the volt-second characteristic of one and only one phase of the series gap is lower than the volt-second characteristics of the other phases of the series gap and the insulator, and the interphase short circuit fault caused by lightning is reduced.

Preferably, the series gap is adjusted in distance so that the volt-second characteristic of the series gap is below the volt-second characteristic of the fused state of the fuse of the corresponding tower of the adjacent at least one tower, and the protection range of the shunt lightning arrester extends to the tower of the adjacent at least one tower, and the shunt lightning arresters are continuously installed adjacent to each other to defend against multiple lightning strikes.

Preferably, the fusing capacity is preset to pass a 10 ampere single-phase earth fault capacitor current or a lightning induced overcurrent having an amplitude of 3000 amperes.

Preferably, the fuse comprises a silver wire with the diameter of 0.2 to 0.4 mm, a copper wire with the diameter of 0.2 to 0.4 mm, an aluminum wire with the diameter of 0.3 to 0.5 mm or a stainless steel wire with the diameter of 0.6 to 0.8 mm, and the surface of the fuse is subjected to corrosion protection treatment.

Drawings

Fig. 1 is a schematic view of a first embodiment of the present invention.

Fig. 2 is a schematic view of a second embodiment of the present invention.

Detailed Description

In order to explain technical contents, structural features, and objects and effects of the present invention in detail, the following description is given in conjunction with the embodiments and the accompanying drawings.

As shown in fig. 1-2, the utility model discloses a parallelly connected arrester is installed in distribution overhead line, include: the fuse tube 7 and the fuse tube 7 ' are connected in parallel in the same direction, the fuse tube 7 and the fuse tube 7 ' respectively comprise an arc-extinguishing tube (respectively marked with the fuse tube 7 and the fuse tube 7 '), and a fuse 17, the fuse 17 is preset with fusing capacity, penetrates through an electrode part 6 (electrode part 6 ') and a joint part 8 which are electrically connected with the arc-extinguishing tube 7 and the arc-extinguishing tube 7 ', and the joint part 8 is electrically connected with a tower 9; the series gap 5 is formed by a difference gap with adjustable distance between the electrode part 6 and the insulated conductor 12 (bare conductor 14); if the series gap 5 is broken down by lightning, the fault current is smaller than the fusing capacity, the fuse 17 is not fused, and the gap arc is automatically extinguished; if the series gap 5 is broken down by lightning, the fault current is larger than the fusing capacity, the fuse 17 is fused, and the electric arc in the tube is extinguished by the arc extinguishing tube 7 and the arc extinguishing tube 7', so that the insulator 10 is protected from being ablated by the electric arc, and the lightning strike trip of the power distribution overhead line is avoided.

The series gap 5 is connected in parallel through the protective tube 7 and the protective tube 7' and then is additionally arranged on the insulator 10 in series, so that the insulator 10 is prevented from being damaged by lightning. It consists of two electrodes, an insulated conductor 12 (bare conductor 14) is on the high voltage side, and the electrode portion 6 is at ground potential. The gap distance is smaller than the lightning discharge distance (insulation structure length) of the insulator 10. When the overhead line is struck by lightning, a high lightning overvoltage is generated on the insulator 10, but the lightning impulse discharge voltage of the series gap 5 is lower than the discharge voltage of the insulator string, so the series gap 5 is discharged first. Because distribution overhead line generally adopts the neutral point ungrounded mode or through arc suppression coil ground connection, allow to continue to operate a period of time (can set for, like 2 hours) during single-phase ground connection, after lightning induction overvoltage punctures series gap 5, single-phase earth fault current is less than 10 amperes, and the predetermined fusing capacity 10 amperes after two fuses 17 connect in parallel, fuse 17 does not fuse, and the electric arc on the series gap 5 can extinguish by oneself because of the energy is less, and insulator 10 receives the protection. When induction overvoltage caused by multiple lightning strokes occurs, the series gap 5 of the parallel lightning arrester can be repeatedly discharged for multiple times without damage and failure, and the insulator can be repeatedly protected for multiple times. Lightning induced faults in distribution overhead lines are caused by lightning induced overvoltages in about 80%. The technical characteristics that the distance between an electrode part 6 and an insulated conductor 12 (a bare conductor 14) of a series gap 5 is adjustable are utilized, so that the series gap 5 of the same base tower is distributed according to differentiation, the distance of the series gap 5 is the minimum, single-phase grounding can be only caused with higher probability, and the electric arc of continuous power frequency capacitance current is led to the end part of a metal electrode through a discharge channel formed by the series gap 5 under the action of electrodynamic force and thermal stress and is fixed between the two end parts of the metal electrode for combustion, so that an insulator is protected from arc ignition, the probability of circuit tripping is greatly reduced, and a first safety is provided for an overhead line.

Distribution overhead line's thunder and lightning trouble about 20% is that the direct lightning causes, can make the three-phase simultaneous occurrence ground short circuit basically, punctures after series gap 5 when the thunder and lightning, and fault current is greater than predetermineeing fusing capacity, and fuse 17 fuses, and the electric arc of production is extinguished by arc extinguishing tube 7, can avoid distribution overhead line tripping operation. The protection radius of the lightning arrester is about 100 meters, and the lightning arresters are installed in parallel on 5 base rod towers in total before and after the first breakdown point, so that at most 5 heavy lightning strikes can be prevented, and a second insurance is provided for the overhead line.

The parallel lightning arrester has the advantages of double insurance, simple structure, safety and reliability, longer service life, great reduction of maintenance amount and remarkable economical efficiency compared with the prior art, and can basically eliminate lightning trip and disconnection by comprehensive popularization and application.

As shown in fig. 1, which is a first embodiment of the present invention, a gas-generating arc-extinguishing method is applied to a bare conductor. The arc-extinguishing tube 7 comprises a glass fiber insulating tube and a gas-generating material layer 16 lined in the glass fiber insulating tube, the gas-generating material layer 16 is made of high polymer materials such as vulcanized fiber paper, nylon and the like, and gas decomposed by high-temperature burning of electric arcs in the tube is sprayed out from the electrode part 6 or the joint part 8 to form longitudinal arc extinguishing. The sprayed gas contains a large amount of charged ions, and the arc extinguishing tube 7 is parallel to the conducting wire, so that the phenomenon that the insulation performance of the interphase is reduced to cause the interphase short circuit can be avoided.

The electrode part 6 is sleeved with an indicating cover (which is marked with the electrode part 6), the appearance color of the indicating cover 6 is different from that of the arc extinguishing tube 7, in the embodiment, the indicating cover 6 is made of aluminum alloy with primary color, the arc extinguishing tube 7 is orange, and after the indicating cover 6 is flushed by gas, the orange arc extinguishing tube 7 is exposed out of the electrode part 6 and can be found by inspection. The joint part 8 is provided with a pressure release cover 18, and the gas pressure exceeds the preset bearing force of the pressure release cover 18 to burst the pressure release cover 18 for spraying, so that the arc extinguishing tube 7 is prevented from bursting. The cross arm structure and the insulator 10 of the pole tower 9 are staggered at the joint part 8, so that the problem that the pressure relief of high-pressure gas is blocked, the flowing direction of the gas is changed, and the interphase insulation performance is reduced is avoided.

The arc striking electrode 2 comprises a clamping part 1 clamped on an electrode part 6 and an electrode part 6' and electrically connected, a series gap 5 with volt-second characteristics in alternate difference fit is formed between the discharge electrode 4 and the bare conductor 14, and the distance of the series gap 5 can be adjusted by rotating the arc striking electrode 2. The volt-second characteristic matching is set to have a difference of 10% -30%, optimization can also be obtained through tests, and when the difference is small in clearance matching, the reduction range of lightning resistance level of a line caused by the fact that a series connection clearance is additionally arranged can be reduced. For the overhead power distribution line erected in a single loop, when three-phase insulators are of the same type, the series gap 5 of the upper conductor of one phase can be selected to be 70% of the minimum arc distance of the insulator 10, and the series gap 5 of the other conductor of the two phases can be selected to be 85% of the minimum arc distance of the insulator 10. For the overhead power distribution line erected in the double loop, when the three-phase insulators are of the same type, the series gap 5 of the upper phase conductor can be selected to be 70% of the minimum arc distance of the insulator 10, and the series gap 5 of the other two-phase conductor and the other loop three-phase conductor is selected to be 85% of the minimum arc distance of the insulator 10. For one or more circuits erected on the same tower, the set value of the series gap 5 of one circuit is smaller than that of other phases, the series gap has volt-second characteristic matching, when induced overvoltage is caused by lightning nearby the circuits or the electric potential of the tower rises to form counterattack voltage, the series gap 5 with a small set value has the chance of being punctured first to form single-phase grounding, further forms coupling effect on the wires of the other phases, reduces the probability of grounding short circuit of two phases or three phases at the same time, the fault current of the grounding short circuit of the two phases or three phases at the same time usually reaches the kiloampere level, the fuse 17 can be fused, and the arc extinguishing tube 7 starts arc extinguishing. When an overhead line close to the transformer substation accessory is struck by lightning, the short-circuit current can reach about 20kA, the arc extinguishing capacity can be increased by 2 times to the maximum extent by the aid of the protective tubes 7 and 7' which are connected in parallel compared with a single protective tube, and the lightning protection requirement of a line in a section with large short-circuit current of a power system is met.

As shown in fig. 2, a second embodiment of the present invention is to apply a gas-generating arc-extinguishing method to an insulated wire, which is different from the first embodiment in that an insulating layer is added to the wire. When the insulating layer is punctured, the electric arc is fixed in the punching hole for burning, so that the wire breaking accident is easily caused, and the insulated wire must be prevented from being broken by lightning.

The arc starting electrode 3 is mounted on the insulated wire 12, the discharge electrode comprises a first discharge electrode 19 extending towards the load side (right side in the figure) of the insulated wire 12 and a second discharge electrode 18 extending towards the power supply side (left side in the figure) of the insulated wire 12, the first discharge electrode 19 and the discharge electrode 4 form a series gap 5, the second discharge electrode 18 and the joint part 8 form a backup gap 11, the volt-second characteristic of the series gap 5 is lower than that of the backup gap 11, the volt-second characteristic of the backup gap 11 is lower than that of the insulator 10, and after the fuse 17 (not shown) is fused, the backup gap 11 provides a breakdown discharge channel to prevent the insulated wire 12 and the insulator 10 from being ablated by an arc. The clamping part adopted by the arc striking electrode 3 is electrically connected with the conductor of the lead 12 in a puncturing mode, and the insulating sleeve 13 is covered outside the arc striking electrode, so that the exposure of the conductor is reduced. The ends of the first discharge electrode 19 and the second discharge electrode 18 are provided with spherical discharge metal structures which can be used for hanging grounding wires during maintenance. The arc striking electrode 3 is clamped on the insulated conducting wire 12, and the discharge current of the series gap 5 can directly flow to the conductor of the insulated conducting wire 12 through the arc striking electrode 3, so that the arc breakdown of the insulating layer is avoided to cause wire breakage.

The arc striking electrode 2 comprises an electrode part 6 and an electrode part 6' which are clamped by a clamping part 1 and are electrically connected, a series gap 5 with volt-second characteristics which are alternately matched is formed between the discharge electrode 4 and the first discharge electrode 19, and the distance of the series gap 5 can be adjusted by rotating the arc striking electrode 2.

In the two embodiments shown in fig. 1 to 2, the fusing capacity of the fuse 17 is preset to pass 10 amperes of single-phase earth fault capacitance current. The fuse 17 comprises a silver wire with the diameter of 0.2 to 0.4 mm, a copper wire with the diameter of 0.2 to 0.4 mm, an aluminum wire with the diameter of 0.3 to 0.5 mm or a stainless steel wire with the diameter of 0.6 to 0.8 mm, and the surface of the fuse 17 is subjected to anticorrosion treatment, such as silver or gold electroplating. The material of the fuse 17 is not limited to the above, and may be other metals or non-metals, and in this embodiment, a silver wire with a diameter of 0.2 to 0.4 mm is preferred.

The series gaps 5 are arranged on a multi-phase insulated wire 12 (or a bare wire 14) of a tower 9, the clamping position of the arc striking electrode 2 is adjusted through rotation, the distance of each series gap 5 is preset, and the volt-second characteristic inter-phase difference matching is realized, so that the volt-second characteristic of one phase of series gap 5 is positioned below the volt-second characteristics of the rest phase of series gaps 5 and the insulator 10, and the inter-phase short circuit fault caused by thunder is reduced.

The distance of the series gap 5 is adjusted, so that the volt-second characteristic of the series gap 5 is lower than the volt-second characteristic of the fusing state of the same phase fuse 17 of at least one adjacent base tower 9, the protection range of the parallel lightning arrester extends to at least one adjacent base tower, and the parallel lightning arresters are adjacently and continuously installed to defend multiple lightning strikes. When the distribution overhead line is subjected to multiple lightning strikes, the tower 9 with the fused fuse 17 is protected by the parallel lightning arrester on the adjacent tower.

The gas-generating arc-extinguishing lightning protection device with the parallel lightning arresters has higher arc-extinguishing capacity and can cut off larger short-circuit current, is suitable for overhead line sections with extremely large short-circuit current, is safe and reliable, realizes the lightning protection of full coverage of the power distribution overhead line, and basically eliminates lightning trip and disconnection.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the invention, therefore, the invention is not limited thereto.

Claims

1. The utility model provides a parallelly connected arrester installs in distribution overhead line, its characterized in that includes:

the fuse protector comprises arc extinguishing tubes and fuses, wherein the fuses are preset with fusing capacity and penetrate through electrode parts and joint parts of the arc extinguishing tubes to be electrically connected, the electrode parts of the fuse protectors are electrically connected, and the joint parts are fixedly connected to a tower after being electrically connected;

a series gap formed by a difference gap with adjustable distance between the electrode part and the lead;

if lightning breaks through the series gap, the fault current is smaller than the parallel fusing capacity of each fuse, the fuses are not fused, and the gap arc is automatically extinguished;

if the series gap is broken down by thunder, the fault current is larger than the parallel fusing capacity of each fuse, the fuses fuse, and the arc in the tube is extinguished by the arc extinguishing tube.

2. The parallel lightning arrester as claimed in claim 1, wherein the arc extinguishing tube comprises an insulating tube and a gas generating material layer lined inside the insulating tube, the gas generating material layer is burned by the high temperature of the arc inside the tube to decompose gas and eject out of the electrode part to form a longitudinal arc quenching, or the joint part is provided with a pressure releasing cover, and the gas pressure exceeds the preset bearing force of the pressure releasing cover to eject out the pressure releasing cover, so as to avoid the explosion of the arc extinguishing tube.

3. The parallel lightning arrester according to claim 2, wherein the electrode portion encloses an indicating cover, the indicating cover has a different color from the arc-extinguishing tube, and the indicating cover is pushed away by high-pressure gas or a compression spring when the fuse is blown, so as to be detected by inspection.

4. The shunt arrester according to any one of claims 1 to 3, wherein the series gap is adjusted in gap distance by at least one arc starting electrode or the joint part, so that volt-second characteristics of the series gap are lower than insulator volt-second characteristics, the arc starting electrode is composed of a conductor and comprises a clamping part and a discharge electrode, and the clamping part is clamped on the electrode part or the lead.

5. The shunt arrester of claim 4 wherein said conductor is an insulated conductor, and said discharge electrodes comprise a first discharge electrode extending toward said load side of said insulated conductor and a second discharge electrode extending toward said power side of said insulated conductor, said first discharge electrode and said electrode portion forming a series gap, said second discharge electrode and said terminal portion forming a back-up gap, said series gap having a volt-second characteristic below that of said back-up gap, said back-up gap having a volt-second characteristic below that of said insulator, said back-up gap providing a path for arcing after said fuse is blown, thereby preventing said insulated conductor and said insulator from being ablated by an arc.

6. The surge arrester of claim 4 wherein the series gap is adjusted in distance such that the volt second characteristic of one and only one phase of the series gap is below the volt second characteristic of the remaining phases of the series gap and the insulator to reduce lightning induced short circuit faults between the phases.

7. The shunt arrester of claim 4 wherein said series gap is adjusted in distance such that a volt-second characteristic of said series gap is below a volt-second characteristic of an adjacent at least one of said towers in a blown condition of said respective fuse, said shunt arrester having a range of protection extending to said adjacent at least one of said towers, said shunt arresters being mounted in series adjacent to each other to protect against multiple lightning strikes.

8. A shunt arrester according to claim 1 characterized in that the fusing capacity is predetermined to pass 10 amps single phase earth fault capacitive current or a lightning induced over-current of magnitude 3000 amps.

9. The parallel lightning arrester as claimed in claim 1, wherein the fuse comprises a silver wire with a diameter of 0.2 to 0.4 mm, a copper wire with a diameter of 0.2 to 0.4 mm, an aluminum wire with a diameter of 0.3 to 0.5 mm or a stainless steel wire with a diameter of 0.6 to 0.8 mm, and the surface of the fuse is subjected to anticorrosion treatment.