CN113594870A

CN113594870A - Transformer counterattack overvoltage protector

Info

Publication number: CN113594870A
Application number: CN202110911252.XA
Authority: CN
Inventors: 王嬿蕾; 王巨丰; 宋永锋; 李�浩; 何琪文; 贾征浩; 陈宇宁; 卢杨; 骆耀敬
Original assignee: Nanning Chaofu Electric Technology Co ltd
Current assignee: Nanning Chaofu Electric Technology Co ltd
Priority date: 2021-08-09
Filing date: 2021-08-09
Publication date: 2021-11-02

Abstract

The invention discloses a transformer counterattack overvoltage protection device, which belongs to the technical field of lightning protection and arc extinction and comprises a plurality of lightning-induced pins, a telegraph pole and a transformer, wherein the lightning-induced pins are arranged at the top of the telegraph pole, the vertical height of the lightning-induced pins is higher than that of a power transmission line arranged on the telegraph pole, the transformer is arranged on the telegraph pole, and the bottom of the lightning-induced pins is grounded. The invention reduces the leakage current allowance and reduces the induced lightning overvoltage. The recoil lightning rod can reduce the amount of electric arcs flowing through the lightning rod, and the recoil pipe reversely sprays most of the electric arcs, so that lightning current is reduced, and the degree of lightning stroke influence on a tower, a transformer and a lightning arrester is reduced. The discharge time is prolonged, and the discharge intensity is reduced. The device converts strong current into weak current, reduces the value of the back-striking voltage, and improves the safety capability of the transformer and the lightning arrester.

Description

Transformer counterattack overvoltage protector

Technical Field

The invention relates to the technical field of lightning protection and arc extinction, in particular to a transformer counterattack overvoltage protection device.

Background

The height of the tower for placing the transformer is basically more than 3 meters, and the tower is easy to be struck by lightning in places with high terrain such as hillsides and the like. Due to the fact that the grounding resistance of the tower is large, when lightning current leaks into the ground through the tower grounding device, the ground potential can rise, and high counterattack voltage is generated. The shell of the transformer is connected with the cross arm of the tower, the shell of the transformer can generate a very high potential, and the huge lightning energy can cause the explosion of the transformer.

At present, the insulation of a transformer generally adopts the mode that a metal shell of the transformer, a grounding wire of a lightning arrester and a neutral point at the low-voltage side of the transformer are connected and then are grounded together, however, the method can only strengthen the longitudinal insulation of the transformer and has no protection effect on turn-to-turn insulation of the transformer, when a high-voltage side or low-voltage side circuit of the transformer is struck by lightning, the lightning passes through a wave to act on a winding of the transformer, and the insulation of the winding is failed due to lightning overvoltage, so that flashover occurs. When the low-voltage side circuit is struck by lightning, the lightning current invades the low-voltage winding and is put into the ground through the neutral grounding device, and the grounding current generates voltage drop on the grounding resistor. This voltage drop causes a sharp increase in the low-voltage-side neutral point potential. It is superimposed on the low voltage winding and causes overvoltage, which endangers the low voltage winding. Meanwhile, the voltage is increased to the high-voltage side according to the transformation ratio through the electromagnetic induction of the high-voltage winding and the low-voltage winding, and the voltage is superposed with the phase voltage of the high-voltage winding, so that dangerous overvoltage occurs in the high-voltage winding. When the high-voltage side line is struck by lightning, the lightning current is discharged into the ground through the high-voltage side lightning arrester, and the ground current generates voltage drop on the ground resistor. This voltage drop acts on the low-side neutral point, and the low-side outlet line is then equivalent to being connected to ground via a resistor, so that the voltage is applied for the most part to the low-voltage winding. And through electromagnetic induction, the voltage drop is increased to the high-voltage side in a transformation ratio and is superposed on the phase voltage of the high-voltage winding, so that the overvoltage occurs in the high-voltage winding to cause breakdown accidents.

Disclosure of Invention

The invention aims to provide a transformer counterattack overvoltage protection device, which solves the technical problems of large grounding resistance, large lightning current, weak transformer insulation, frequent action and easy damage of a lightning arrester of the existing transformer. The recoil lightning rod is arranged at the top of the tower and can rapidly cut off electric arcs, so that the amplitude and gradient of lightning current are reduced, the ground current is very small, the damage to the transformer caused by the counterattack voltage and induced lightning overvoltage in a circuit caused by the leakage of the lightning current is avoided, and the lightning damage accident of the transformer is reduced.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides a transformer counterattack overvoltage protector, includes a plurality of lightning strike needle, wire pole and transformer, and the lightning strike needle sets up at the top of wire pole, and vertical height is higher than the power transmission line that sets up on the wire pole, and the transformer sets up on the wire pole, and lightning strike needle bottom ground connection.

The lightning strike needle includes the striking pointed end, arc control device and bottom screw rod, the striking pointed end sets up on arc control device's top, the bottom screw rod sets up in arc control device's bottom and ground connection setting, arc control device includes one and above sealed arc extinguishing unit, perhaps recoil arc extinguishing unit and one and above sealed arc extinguishing unit, sealed arc extinguishing unit and sealed arc extinguishing unit end to end fixed connection, the bottom ground connection of the lightning protection device of bottommost, recoil arc extinguishing unit sets up the top at sealed arc extinguishing unit.

Furthermore, the sealed arc extinguishing unit is arranged to be a sealing tube, the two ends of the sealing tube are respectively provided with an upper electrode and a lower electrode which are sealed, insulating oil is arranged in the sealing tube, and the side edge of the sealing tube is provided with a skirt edge.

Further, the sealing tube further comprises a ceramic tube and a protective shell, the protective shell is arranged on the outer side of the ceramic tube, and the skirt edge is arranged on the outer side of the protective shell.

Further, the upper electrode comprises an upper graphite electrode, a middle metal electrode and a lower graphite electrode, the middle metal electrode is fixed at one end of the ceramic tube and one end of the protective shell, the upper graphite electrode is arranged on the upper layer of the middle metal electrode, the lower graphite electrode is arranged at the bottom of the middle metal electrode and is arranged in the ceramic tube, the lower electrode comprises an upper graphite electrode and a bottom metal electrode, the bottom metal electrode is fixed at the other end of the ceramic tube and the other end of the protective shell, and the upper graphite electrode is arranged in the ceramic tube and is connected with the bottom metal electrode.

Furthermore, the sealed arc extinguishing unit is arranged to be a sealing tube, the two ends of the sealing tube are respectively provided with an upper electrode and a lower electrode which are sealed, insulating oil is arranged in the sealing tube, the side edge of the sealing tube is provided with a skirt edge, arc extinguishing grids are arranged on the inner side edge of the sealing tube at intervals, and the transverse length of each arc extinguishing grid is larger than the half inner diameter of the sealing tube.

Furthermore, the bottom of the upper electrode is provided with an upper tip electrode, the upper end of the lower electrode is provided with a lower tip electrode, the upper tip electrode and the lower tip electrode are arranged vertically relatively, and the upper tip electrode and the lower tip electrode are graphite electrodes.

Further, the arc extinguishing bars are made of insulating materials, the arc extinguishing bars are arranged into semicircular structures, the arc extinguishing bars arranged on the inner side walls of the two semicircles in the sealing tube are arranged alternately, convex piers are arranged between the arc extinguishing bars on the same semicircle, and the convex piers on the inner side wall of one semicircle are arranged opposite to the arc extinguishing bars on the inner side wall of the other semicircle.

Further, recoil arc extinguishing unit includes that the lightning receiving electrode, recoil body, recoil pipe shirt rim and bottom lightning receiving electrode, lightning receiving electrode set up on the top of recoil body, and the recoil pipe shirt rim sets up the side at the recoil body, and the recoil body is inside to be set up to the recoil hole, and the low side of recoil hole is provided with the bottom lightning receiving electrode, lightning receiving electrode and bottom lightning receiving electrode are graphite electrode, are provided with insulating liquid in the recoil body, the sealed bottom that sets up at the recoil hole of bottom lightning receiving electrode.

The specific working process of the protection device is as follows:

step 1: before thunder and lightning forms, a thunder field is formed between thundercloud and the ground, because of electrostatic induction, charges with the polarity opposite to that of the thundercloud are induced in the insulating tube and accumulated in the sealed insulating tube, and because the liquid is incompressible fluid, the charges cannot move freely, and finally an arc chain is formed in the insulating tube; mutually repulsive coulomb force is generated among the charges with the same polarity, and the coulomb force acts on the pipe wall to form reaction force due to the sealing of the insulating pipe, so that the induced charge chain is cut off;

step 2: when arc discharge is initiated in the sealed tube filled with insulating oil, shock waves towards the side edges are generated by the liquid electricity effect;

and step 3: the Pascal effect enhances the liquid electric effect, when electric arcs act on the insulating oil, when a certain part of static insulating oil generates pressure intensity change, the electric arcs constantly transmit the pressure intensity to all directions of the inner side of the sealing pipe;

and 4, step 4: because the arc extinguishing bars are arranged in the sealed tube, the length of the electric arc in the sealed tube is prolonged, the convex piers are arranged to increase the surface area of the sealed tube, and the impact waves of the liquid-electric effect and the Pascal effect return to the side edge and impact the side edge, so that the arc extinguishing is intensively carried out on the electric arc channel, and the overvoltage protection is carried out.

Further, the specific process of step 2 is that arc discharge is initiated in the ceramic tube filled with insulating oil, part of the insulating oil in the discharge channel is instantly vaporized, decomposed and ionized into high-temperature plasma and suddenly expanded to form a mechanical pressure wave which rapidly spreads outwards, but the liquid can be regarded as a shock wave transmission medium which can not be compressed, so that the mechanical effect of power is shown to the outside when the discharge channel carries out liquid-phase discharge, an acting force which impacts the wall of the ceramic tube is formed in the ceramic tube, and the wall of the ceramic tube generates the shock wave in the insulating oil medium due to the interaction of the force;

the specific process of the step 3 is as follows: when an impact electric arc acts on the metal electrode, pressure is applied to insulating oil in the ceramic tube, a certain part of static fluid in the closed container generates pressure change according to the Pascal principle, the pressure is constantly transmitted to all directions, and then the insulating oil medium around is impacted by a larger acting force from a discharge channel in the ceramic tube, and the acting force rebounds after contacting the wall of the ceramic tube;

the concrete process of step 4 is that the pressure in the ceramic tube is increased and the temperature is increased by the liquid electricity effect and the pascal effect, so that an acting force pointing to the center from the ceramic tube wall is generated, under the acting force, the electric arc moves towards the tip of the arc-extinguishing grid, the length of the electric arc is lengthened by the tip, the temperature of the electric arc is reduced by the blowing of the insulating oil to the electric arc, so that the electric arc is extinguished more quickly, the longer the electric arc formed in the ceramic tube is, the larger the acting force is on the ceramic tube wall, the larger the impact force for cutting the electric arc in turn is, the rebounding occurs after the acting force acts on the shell, the acting force pointing to the center of the insulating tube is formed, the electric arc is cut, the current amplitude and gradient are reduced, and the counterattack voltage and the induction lightning overvoltage are avoided to be generated.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

(1) the invention reduces the leakage current allowance and reduces the induced lightning overvoltage. The recoil lightning rod can reduce the amount of electric arcs flowing through the lightning rod, and the recoil pipe reversely sprays most of the electric arcs, so that lightning current is reduced, and the degree of lightning stroke influence on a tower, a transformer and a lightning arrester is reduced.

(2) The discharge time is prolonged, and the discharge intensity is reduced. The high current is converted into the low current through the device, the value of the back-striking voltage is reduced, the safety capability of the transformer and the lightning arrester is improved, the back-striking lightning rod arranged on the tower can effectively protect the safety of the transformer, the damage capability of the lightning current to the transformer and the lightning arrester is weakened, and the safety protection device plays a role in protecting the safety of the device.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the structure of the lightning rod of the invention;

FIG. 3 is a schematic diagram of a first sealed arc extinguishing unit according to the present invention;

fig. 4 is a schematic structural diagram of a second sealed arc extinguishing unit of the invention;

FIG. 5 is a schematic view of a high-pressure seal structure of the arc extinguishing unit of the present invention;

fig. 6 is a schematic view of an external reinforcing structure of the sealed arc extinguishing unit.

In the figure, 1-upper electrode, 2-insulating oil, 3-ceramic tube, 4-skirt edge, 5-protective shell, 6-lower electrode, 7-electric arc, 8-upper tip electrode, 9-arc-extinguishing grid, 10-convex pier, 11-lower tip electrode, 12-arc-striking tip, 13-bottom screw rod, A-sealed arc-extinguishing unit, B-lightning-striking needle, C-telegraph pole and D-transformer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings by way of examples of preferred embodiments. It should be noted, however, that the numerous details set forth in the description are merely for the purpose of providing the reader with a thorough understanding of one or more aspects of the present invention, which may be practiced without these specific details.

As shown in fig. 1, the transformer counterattack overvoltage protection device comprises a plurality of lightning conducting pins B, a telegraph pole C and a transformer D, wherein the lightning conducting pins B are arranged on the top of the telegraph pole C, the vertical height of the lightning conducting pins B is higher than that of a power transmission line arranged on the telegraph pole C, the transformer D is arranged on the telegraph pole C, and the bottom of the lightning conducting pins B is grounded.

As shown in fig. 2, the lightning strike needle includes a striking tip 12, an arc extinguishing device and a bottom screw 13, the striking tip 12 is disposed on the top end of the arc extinguishing device, the bottom screw 13 is disposed on the bottom end of the arc extinguishing device and is grounded, the arc extinguishing device includes one or more than one sealed arc extinguishing units a, the sealed arc extinguishing units a and the sealed arc extinguishing units a are fixedly connected end to end, and the bottom end of the lightning protection device at the bottom end is grounded.

When the electric arc enters the insulating tube, a certain pressure is applied to the liquid in the insulating tube, and according to the Pascal principle, the pressure change of a certain part of the static fluid in the closed container is constantly transmitted to all directions, so that a larger acting force is inevitably generated on the inner wall of the insulating tube. The acting force rebounds after acting on the shell to form an acting force with the direction pointing to the center of the insulating tube, so that the aims of cutting off the electric arc, reducing the current amplitude and avoiding generating huge residual voltage are fulfilled.

In this embodiment, the sealed arc extinguishing unit a is configured as a sealed tube, the two ends of the sealed tube are respectively provided with an upper electrode 1 and a lower electrode 6 which are sealed, the sealed tube is provided with insulating oil 2, and the side edge of the sealed tube is provided with a skirt 4. The sealing tube further comprises a ceramic tube 3 and a protective shell 5, wherein the protective shell 5 is arranged on the outer side of the ceramic tube 3, and the skirt edge 4 is arranged on the outer side of the protective shell 5.

The upper electrode 1 includes upper graphite electrode, middle metal electrode and lower floor's graphite electrode, middle metal electrode fixes the one end at ceramic pipe 3 and protecting sheathing 5, upper graphite electrode sets up the upper strata at middle metal electrode, lower floor's graphite electrode sets up the bottom at middle metal electrode, and set up in ceramic pipe 3, lower electrode 6 includes upper end graphite electrode and bottom metal electrode, the other end at ceramic pipe 3 and protecting sheathing 5 is fixed to bottom metal electrode, upper end graphite electrode sets up in ceramic pipe 3, and be connected with bottom metal electrode.

Example 2:

as shown in fig. 3, the embodiment is different from embodiment 1 in that the sealed arc extinguishing unit a is configured as a sealed tube, the two ends of the sealed tube are respectively provided with an upper electrode 1 and a lower electrode 6 which are sealed, the sealed tube is provided with insulating oil 2, the side edge of the sealed tube is provided with a skirt 4, the inner side edge of the sealed tube is provided with arc extinguishing grids 9 at intervals, and the transverse length of the arc extinguishing grids 9 is greater than one-half of the inner diameter of the sealed tube. The bottom of the upper electrode 1 is provided with an upper tip electrode 8, the upper end of the lower electrode 6 is provided with a lower tip electrode 11, the upper tip electrode 8 and the lower tip electrode 11 are arranged vertically relatively, and the upper tip electrode 8 and the lower tip electrode 11 are both graphite electrodes.

In this embodiment, the arc-extinguishing bars 9 are made of insulating materials, the arc-extinguishing bars 9 are arranged in a semicircular structure, the arc-extinguishing bars 9 arranged on the inner side walls of the two semicircles in the sealed tube are arranged alternately, the convex piers 9 are arranged between the arc-extinguishing bars 9 on the same semicircle, and the convex piers 9 on the inner side wall of one semicircle are arranged opposite to the arc-extinguishing bars 9 on the inner side wall of the other semicircle.

The hydro-electric effect and the Pascal effect enable the pressure in the ceramic tube to be increased, the temperature to be increased, acting force pointing to the center from the wall of the ceramic tube is generated, under the acting force, the electric arc moves towards the tip of the arc-extinguishing grid, the tip lengthens the length of the electric arc, and under the condition that insulating oil blows the electric arc, the temperature of the electric arc is reduced, so that the electric arc is extinguished more quickly, the longer the electric arc formed in the ceramic tube is, the greater the acting force on the wall of the ceramic tube is, and the greater the impact force for cutting off the electric arc is, and arc extinction is completed.

Example 3:

the difference between this embodiment and

embodiment

1 and 2 is that, still include recoil arc extinguishing unit, recoil arc extinguishing unit sets up on sealed arc extinguishing unit A's top, and recoil arc extinguishing unit is including connecing dodging electrode, recoil body, recoil pipe shirt rim and bottom to connect dodging the electrode, connects to dodge the electrode setting on the top of recoil body, and the side at the recoil body is set up to the recoil pipe shirt rim, and the recoil body is inside to set up to recoil vacancy, and the low side of recoil vacancy is provided with the bottom and connects dodging the electrode, it is graphite electrode to connect dodging electrode and bottom to connect and dodge the electrode, is provided with insulating liquid in the recoil body, the sealed bottom that sets up at the recoil vacancy of bottom connects dodging the electrode. The back-flushing unit is arranged to perform back-flushing weakening on the lightning arc, and then the sealed arc extinguishing unit A performs arc extinguishing, so that the current limiting effect can be well achieved.

The graphite electrode is arranged at the lightning receiving place, so that the service life can be effectively prolonged.

The graphite electrode has good conductivity, and is easy to introduce electric arc into the recoil pipe: graphite is a non-metallic material, and the conductivity of graphite is 100 times higher than that of general non-metallic ore. Graphite is an electrical conductor in that the periphery of each carbon atom in graphite is linked to three other carbon atoms arranged in a honeycomb pattern of many hexagons, and since each carbon atom gives off an electron, those electrons are free to move. Generally, the electrical discharge machining speed of the graphite electrode is 1.5 to 2 times faster than that of the copper electrode as a whole. When the power transmission line is struck by lightning, the graphite electrode can play a role in striking arcs, so that the arcs can smoothly enter the arc extinguishing pipe.

The graphite electrode has extremely high melting point, can bear larger current and is not easy to deform: graphite electrodes have the property of being able to withstand high current conditions. The softening point of copper is about 1000 ℃, and the copper is easy to deform due to heating; and the sublimation temperature of the graphite is about 3650 ℃. Lightning strike currents of between 5000 amperes and 5 kiloamperes, producing lightning strike temperatures of up to 3000 degrees. Therefore, the metal electrode is easy to deform under the action of lightning strike heavy current, generates metal powder, splashes, damages the structure of the arc extinguish chamber and influences the effect of recoil arc extinction, and the graphite electrode can effectively solve the problems.

The loss of the graphite electrode is small: the graphite electrode has the characteristic of bearing a large current condition, a polarity effect is generated under the action of lightning arcs, partial corrosion removal objects and carbon particles can be adhered to the surface of the electrode to form a protective layer, and the graphite electrode is ensured to have extremely low loss or even zero loss in the process of recoil arc extinguishing.

The specific working process of the protection device is as follows:

step 2: when arc discharge is initiated in the sealed tube filled with insulating oil, the electrohydraulic effect generates shock waves which impact to the side edges. Arc discharge is initiated in the ceramic tube filled with insulating oil, part of the insulating oil in the discharge channel is instantly vaporized, decomposed and ionized into high-temperature plasma and suddenly expanded to form a mechanical pressure wave which is rapidly propagated outwards, but the liquid can be regarded as a shock wave transmission medium which can not be compressed, so that when the discharge channel is subjected to liquid-phase discharge, the mechanical effect of power is shown to the outside, an acting force which impacts the wall of the ceramic tube is formed in the ceramic tube, and the wall of the ceramic tube generates shock waves in the insulating oil medium due to the force interaction;

and step 3: the Pascal effect enhances the liquid electric effect, when the electric arc acts on the insulating oil 2, and when a certain part of the static insulating oil 2 generates pressure intensity change, the electric arc is constantly transmitted to all directions of the inner side of the sealing pipe. When an impact electric arc acts on the metal electrode to apply pressure to the insulating oil in the ceramic tube, according to the Pascal principle, a certain part of static fluid in the closed container generates pressure change, the pressure is constantly transmitted to all directions, and then the insulating oil medium around is impacted by a larger acting force from a discharge channel in the ceramic tube, and the acting force rebounds after contacting the wall of the ceramic tube.

And 4, step 4: because the arc extinguishing grid 9 is arranged in the sealed tube, the length of the electric arc in the sealed tube is lengthened, meanwhile, the convex pier 9 is arranged to increase the surface area of the sealed tube, and the shock waves of the liquid-electricity effect and the Pascal effect return to the shock after impacting the side edge, so that the electric arc channel is intensively subjected to shock arc extinguishing for overvoltage protection. The hydro-electric effect and the Pascal effect enable the pressure in the ceramic tube to be increased, the temperature to be increased, acting force pointing to the center from the ceramic tube wall is generated, under the acting force, the electric arc moves towards the tip of the arc-extinguishing grid, the tip lengthens the length of the electric arc, under the condition that insulating oil blows the electric arc, the temperature of the electric arc is reduced, the electric arc is extinguished more quickly, the longer the electric arc formed in the ceramic tube is, the larger the acting force on the ceramic tube wall is, the larger the impact force for cutting the electric arc in reverse is, the action force rebounds after acting on the shell, the acting force pointing to the center of the insulating tube is formed, the electric arc is cut, the amplitude and the gradient of current are reduced, counterattack voltage is avoided, and induced lightning overvoltage is reduced.

The gland 12 is provided with a high pressure seal and external reinforcement as shown in figures 5-6.

The high-pressure sealing structure comprises a plastic sleeve 21, a stainless steel gasket 22, an O-shaped ring 23, a steel sleeve 24, sealing silica gel 25 and an extrusion fixing block 26, electrodes are nested in the sealing silica gel 25, the sealing silica gel 25 is arranged at two ends of the ceramic tube in a sealing mode, the steel sleeve 24 is fastened on the outer side of the joint of the sealing silica gel 25 and the ceramic tube, and the plastic sleeve 21 is sleeved on the outer sides of the steel sleeve 24 and the ceramic tube. A stainless steel gasket 22 is padded at the front end of the electrode and an O-ring 23 is placed between the sealing silica gel 25 and the ceramic tube contact. The extrusion fixed block 26 is arranged on the outer side of the sealing silica gel 25, a bolt hole 27 is arranged on the extrusion fixed block 26, and the bolt hole 27 is arranged in contact with the stainless steel gasket 22. The sealing silica gel 25 is set to be a T-shaped structure silica gel, and the bottom of the T-shaped structure silica gel is set to be a spherical concave structure.

The shell is made of plastic insulating materials and is used for fixing the ceramic tube; the steel sleeves are arranged at two ends of the ceramic tube to fix the end part of the ceramic tube and prevent the ceramic tube from being mechanically deformed by the generated high-strength pressure; the upper and lower electrodes are wrapped up in the silica gel that is half arc, and narrow and small space when upper and lower electrode arc extinguishing, the area is little, produces the pressure dispersion phenomenon, wraps up the electrode with the silica gel of half arc and can focus the pressure wave, and the pressure of arc extinguishing passageway improves several times, effectively blocks the electric arc. The screw generates thrust to the stainless steel gasket and the silica gel assembly, so that the stainless steel gasket and the silica gel assembly are tightly matched with the O-shaped ring and the ceramic tube, the purpose of high-pressure sealing is achieved, high-strength pressure is well prevented from leaking, and the generated high-strength pressure can be guaranteed to act on the electric arc to the maximum.

When the device is struck by lightning, a liquid-electricity effect is generated, a strong impact pressure wave is formed, and the strong impact pressure wave acts on a discharge channel in an impulse or impact pressure mode to cut off electric arcs. Meanwhile, a certain pressure is applied to the arc extinguishing liquid in the ceramic tube, and according to the Pascal principle, the pressure change of a certain part of the static fluid in the closed container is transmitted to all directions invariably, so that a larger acting force is generated on the inner wall of the ceramic tube. The action rebounds after acting on the shell to form an action force with the direction pointing to the center of the ceramic tube, so that the purposes of cutting off the electric arc, reducing the amplitude of the current, reducing the gradient of the lightning wave and prolonging the discharge time of the electric arc are achieved, the arc is effectively extinguished, the structure is simple, and the sealing performance is good.

The external reinforcing structure comprises a top cover plate 31, an insulating screw 33, a bottom cover plate 34 and an insulating cover layer 35, wherein the top cover plate 33 is arranged at the top and the bottom of the high-pressure sealing device

The sleeve cover plate 34 is arranged at the bottom of the high-pressure sealing device, the insulating screw 33 penetrates through the top sleeve cover plate 31 and the bottom sleeve cover plate 34 and is fixedly arranged, the insulating covering layer 35 is arranged on the outer side of the high-pressure sealing device, the top sleeve cover plate 31 and the bottom sleeve cover plate 34 respectively support against the extrusion fixing block 26, and meanwhile the top sleeve cover plate 31 and the bottom sleeve cover plate 34 are provided with screw holes. The fixed effect is better, and the whole arc extinguishing device can bear larger pressure.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.

Claims

1. The utility model provides a transformer counterattack overvoltage protector which characterized in that: the lightning conducting device comprises a plurality of lightning conducting pins (B), a telegraph pole (C) and a transformer (D), wherein the lightning conducting pins (B) are arranged at the top of the telegraph pole (C), the vertical height of the lightning conducting pins (B) is higher than that of a power transmission line arranged on the telegraph pole (C), the transformer (D) is arranged on the telegraph pole (C), and the bottom of the lightning conducting pins (B) is grounded.

2. A transformer strike overvoltage protection device as claimed in claim 1 wherein: lightning strike needle (B) is including striking most advanced (12), arc control device and bottom screw rod (13), and striking most advanced (12) set up on arc control device's top, and bottom screw rod (13) set up in arc control device's bottom and ground connection setting, and arc control device includes one and more sealed arc extinguishing unit (A), and sealed arc extinguishing unit (A) end to end meet fixed connection, the bottom ground connection of the lightning protection device of bottom.

3. A transformer strike overvoltage protection device as claimed in claim 2 wherein: sealed arc extinguishing unit (A) sets up to a sealed tube, and the sealed tube both ends set up electrode (1) and lower electrode (6) sealed setting respectively, are provided with insulating oil (2) in the sealed tube, and the side of sealed tube is provided with shirt rim (4), and the sealed tube still includes ceramic pipe (3) and protecting sheathing (5), and protecting sheathing (5) set up in the outside of ceramic pipe (3), and shirt rim (4) set up in the outside of protecting sheathing (5).

4. A transformer strike overvoltage protection device according to claim 3, wherein: upper electrode (1) includes upper graphite electrode, middle metal electrode and lower floor's graphite electrode, middle metal electrode fixes the one end at ceramic pipe (3) and protecting sheathing (5), upper graphite electrode sets up the upper strata at middle metal electrode, lower floor's graphite electrode sets up the bottom at middle metal electrode, and set up in ceramic pipe (3), lower electrode (6) are including upper end graphite electrode and bottom metal electrode, the other end at ceramic pipe (3) and protecting sheathing (5) is fixed to bottom metal electrode, upper end graphite electrode sets up in ceramic pipe (3), and be connected with bottom metal electrode.

5. A transformer strike overvoltage protection device as claimed in claim 2 wherein: the sealed arc extinguishing unit (A) is arranged to be a sealed tube, the two ends of the sealed tube are respectively provided with an upper electrode (1) and a lower electrode (6) which are sealed, insulating oil (2) is arranged in the sealed tube, the side edge of the sealed tube is provided with a skirt edge (4), arc extinguishing grids (9) are arranged on the inner side edge of the sealed tube at intervals, and the transverse length of each arc extinguishing grid (9) is greater than the half inner diameter of the sealed tube.

6. A transformer strike overvoltage protection device according to claim 5, wherein: the bottom of the upper electrode (1) is provided with an upper tip electrode (8), the upper end of the lower electrode (6) is provided with a lower tip electrode (11), the upper tip electrode (8) and the lower tip electrode (11) are vertically arranged relatively, and the upper tip electrode (8) and the lower tip electrode (11) are graphite electrodes.

7. A transformer strike overvoltage protection device according to claim 5, wherein: arc extinguishing bars (9) are made by insulating material, and arc extinguishing bars (9) set up to semicircular structure, and arc extinguishing bars (9) that two semicircle inside walls set up in the sealed tube set up alternately, are provided with protruding mound (9) between arc extinguishing bars (9) on the same semicircle, and protruding mound (9) of a semicircle inside wall set up with arc extinguishing bars (9) of another semicircle inside wall relatively.

8. A transformer strike overvoltage protection device according to claim 5, wherein: the back-flushing arc extinguishing unit comprises a flash electrode, a back-flushing pipe skirt and a bottom flash electrode, the flash electrode is arranged on the top of the back-flushing pipe body, the back-flushing pipe skirt is arranged on the side edge of the back-flushing pipe body, a back-flushing hole is formed in the back-flushing pipe body, the bottom of the back-flushing hole is provided with a bottom flash electrode, the flash electrode and the bottom flash electrode are graphite electrodes, insulating liquid is arranged in the back-flushing pipe body, and the bottom flash electrode is arranged at the bottom of the back-flushing hole in a sealing mode.

9. A transformer strike overvoltage protection device according to claim 5, wherein: the specific working process of the protection device is as follows:

and step 3: the Pascal effect enhances the liquid electric effect, when electric arcs act on the insulating oil (2), and when a certain part of the static insulating oil (2) generates pressure intensity change, the electric arcs constantly transmit the pressure intensity to all directions of the inner side of the sealing pipe;

and 4, step 4: because arc extinguishing bars (9) are arranged in the sealed tube, the length of the electric arc in the sealed tube is lengthened, meanwhile, the convex piers (9) are arranged to increase the surface area of the sealed tube, and the impact waves of the liquid-electric effect and the Pascal effect return to impact after impacting the side edges, so that the electric arc channel is intensively impacted and extinguished to perform overvoltage protection.

10. A transformer strike overvoltage protection device according to claim 9, wherein:

initiating arc discharge in the ceramic tube filled with insulating oil, wherein part of the insulating oil in the discharge channel is instantly vaporized, decomposed and ionized into high-temperature plasma and suddenly expanded to form a mechanical pressure wave which is rapidly propagated outwards, but the liquid can be regarded as a shock wave transmission medium which can not be compressed, so that the mechanical effect of power is shown to the outside when the discharge channel is subjected to liquid-phase discharge, an acting force impacting the wall of the ceramic tube is formed in the ceramic tube, and the wall of the ceramic tube generates a shock wave in the insulating oil medium due to the force interaction;