CN203386547U - Integrated fixed external series gap self-disengaging metal oxide lightning arrester insulators - Google Patents

Abstract

The utility model discloses an integrated fixed external series gap self-detachment metal oxide lightning arrester insulator, the puncture wire clamping hardware is arranged on the top of the post insulator, the bottom end of the post insulator is fixed on the cross arm, and the puncture wire clamping hardware is clamped Holding the insulated wire, the high-voltage electrode arc rod is connected with the piercing clamp fittings, the insulating bracket is parallel to the high-voltage electrode arc rod, and the insulating bracket is respectively connected to the post insulator and the metal oxide arrester. The top of the metal oxide arrester is provided with a hemispherical electrode. The semi-spherical electrode and the high-voltage electrode arc striker form a fixed external series discharge gap, the disconnector and the metal oxide arrester are connected in series, and the grounding end of the disconnector and the cross arm are connected to the ground through the grounding wire. The utility model integrates the lightning arrester and the insulator, which reduces the line cost, simplifies the installation steps, and improves the installation efficiency; the discharge gap of the utility model is fixed, and the insulation coordination is carried out through a large number of lightning experiments, and there is no need for further installation during installation. adjust.

Description

Integrated fixed external series gap self-detachment metal oxide arrester insulator

technical field

The utility model relates to a lightning strike disconnection protection device for a 10kV overhead insulated wire of a distribution network, in particular to an integrated fixed external series gap self-detachment metal oxide lightning arrester insulator.

Background technique

In the distribution network, the use of insulated wires solves the corridor and safety problems that bare wires cannot solve, and it saves investment and builds quickly. However, insulated wires also have their own weaknesses, that is, the problem of disconnection due to lightning strikes. The so-called lightning strikes must be disconnected. According to the theory of lightning breakage of insulated conductors, the corresponding preventive measures include "draining" and "blocking". The so-called "guiding type" is to allow the overhead insulated line to have a certain probability of lightning flashover, so that the arc root of the power frequency freewheeling arc is transferred to the special fittings for burning, so as to protect the wire from arc burns and disconnection. The products that have appeared include arc-proof fittings, discharge clamp insulators, etc. The "drainage" method is simple to implement and requires less investment, but it cannot reduce the number of lightning trips on the line. The so-called "blocking type" is to reduce the lightning flashover probability of the line as much as possible, or prevent the power frequency continuous current arcing after the lightning flashover, so as to prevent the insulated wire from being burned and disconnected. Corresponding measures include strengthening line insulation, erecting lightning protection lines, reducing tower grounding resistance, and installing line-type arresters, etc. Compared with the "draining type", the "blocking type" method has better protection effect, but the disadvantage is that the construction is relatively complicated and the cost is high.

Using the "blocking" method to solve the problem of lightning disconnection, the ideal measure is to install line-type arresters. The products that have appeared include gapless metal oxide arresters and overvoltage protectors. The main defect of the gapless metal oxide arrester in practical application is: the arrester body is directly connected to the power grid, and the zinc oxide valve plate has to withstand the power frequency voltage for a long time, which accelerates the aging of the valve plate, and its safe service life is greatly improved. limited, and the direct electrical connection is also likely to cause certain hidden dangers of electrical accidents. The overvoltage protector uses the outer series gap of the ring electrode to solve the disadvantages of long-term resistance to power frequency voltage. However, if the arrester body is damaged, if the line is subjected to lightning overvoltage at this time, the power frequency If the freewheeling flow cannot be suppressed, it will burn stably, and the insulated wire will still be burned and blown, and even cause the damaged arrester to explode.

In order to automatically fall off and disconnect the damaged arrester when the arrester fails, and to avoid a large number of explosive splashes from injuring people when the arrester explodes, based on the arrester structure, a heat-melt detachment mechanism is connected in series with the outer gap at one end of the arrester to melt The damaged arrester is automatically disconnected from the power grid by means of destruction. Chinese patent: 03213798.2 "AC external gap type automatic detachment arrester", and Chinese patent: 201100644513 "combined series gap is a detachment mechanism arrester" two technical solutions have realized this technical function. The gap-type detachment mechanism is composed of insulating brackets and spherical electrodes with opposite spacing. The spherical electrodes are made of special fusible alloy materials. The cost is high, and the structural assembly parts are many and complicated, which will increase a lot of assembly steps. Moreover, the arrester is used as a post insulator, and it is difficult to replace the arrester when it is damaged.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide an integrated fixed external series gap self-detachment metal oxide arrester insulator, which not only plays the role of insulating and supporting wires, but also enables the metal oxide arrester to be free from power grid work. The action of high-frequency voltage can reliably make the fault arrester out of operation.

The utility model is realized through the following technical proposals. The utility model includes puncture clamping fittings, insulated wires, high-voltage electrode arcing rods, post insulators, insulating brackets, crossarms, metal oxide arresters, disconnectors and grounding wires; The piercing and clamping fittings are set on the top of the post insulator, the bottom of the post insulator is fixed on the cross arm, the piercing and clamping fittings clamp the insulated wires, the high-voltage electrode arc striking rod is connected with the piercing and clamping fittings, the insulating bracket and the high-voltage electrode lead The arc rods are parallel, and the insulating brackets are respectively connected to the post insulator and the metal oxide arrester. The top of the metal oxide arrester is equipped with a semi-spherical electrode, and the semi-spherical electrode and the high-voltage electrode arc rod form a fixed external series discharge gap. The disconnector and the metal oxide The arrester is connected in series, and the ground terminal of the disconnector and the cross arm are connected to the ground through the ground wire.

The piercing and clamping hardware includes an insulating shield and an upper pressing block, a lower pressing block, a connecting piece and spur teeth arranged in the insulating shielding, the upper pressing block is arranged on the lower pressing block, and the upper pressing block and the lower pressing block pass through The connectors are connected, the teeth are symmetrically arranged on the upper and lower pressure blocks, the teeth on the upper pressure block and the teeth on the lower pressure block respectively clamp the insulated wires, and the lower pressure block is connected to the top of the post insulator , the high-voltage electrode arc rod is connected to the lower pressing block.

The connecting piece includes bolts and torque nuts, the upper pressing block and the lower pressing block are respectively sleeved on the bolts, and the torque nuts are screwed on the bolts. The torque nut is adopted, the pressing force is balanced and reliable, which meets the requirements of the current flow capacity, and at the same time does not damage the core wire, ensuring reliable long-term contact between the high-voltage puncture electrode and the core wire.

The thorns are four-tooth stamped sheets made of copper alloy. Higher strength and toughness than aluminum alloy, better electrical conductivity.

Considering that the copper-aluminum alloy is easily oxidized during the transition, an anti-oxidation layer is provided on the surface of the teeth.

The disconnector is connected in series with the lower end of the metal oxide arrester through a threaded external interface, so as to realize reliable serial connection between the disconnector and the metal oxide arrester.

The disconnector is a hot-melt or hot-explosion type, with strong impact resistance, and will not act under the impact of a 2ms square wave or a 4/10μs high current.

As one of the preferred modes of the present utility model, an insulating sleeve is covered on the arc starting rod of the high voltage electrode.

The ground wire is copper multi-strand flexible wire with a cross-sectional area larger than 10mm ² , so that the disconnector can move freely and form a sufficient air gap, so that the fault-damaged arrester can be reliably isolated from the system.

When the lightning voltage amplitude on the insulated wire exceeds the gap discharge voltage, the series gap formed by the high-voltage electrode arc rod and the semi-spherical electrode breaks down. When the metal oxide arrester is working normally, the disconnector does not act and shows low impedance, and the metal oxide arrester enters the low impedance conduction state, which plays the role of limiting the overvoltage at both ends of the post insulator. After the lightning strike, the system operating voltage is added to On the metal oxide arrester, the metal oxide arrester instantly returns to the high-impedance blocking state, the power frequency freewheeling is suppressed in a small range and the arc cannot be established, the insulation performance of the series gap recovers quickly, and the metal oxide arrester and the line recover to Normal operating state; when the metal oxide arrester is damaged and fails, the power frequency fault current passes through the disconnector, and the disconnector operates in a timely, accurate and reliable manner, so that the faulty metal oxide arrester is out of operation, and there is a clear sign of disconnection, which is convenient for inspectors to find Faulty metal oxide arrester.

Compared with the prior art, the utility model has the following advantages:

(1) The utility model integrates the lightning arrester and the insulator, which reduces the line cost, simplifies the installation steps, and improves the installation efficiency;

(2) The discharge gap of the utility model is fixed, and the insulation coordination is carried out through a large number of lightning experiments to determine the value of the discharge gap, and there is no need to adjust it during installation;

(3) Due to the existence of the air insulation gap, the utility model makes the metal oxide arrester get rid of the power frequency voltage of the power grid, and only has the problem of natural aging, which greatly prolongs the service life of the metal oxide arrester;

(4) When the metal oxide arrester is damaged by lightning protection, especially when the single-phase arc light grounding resonance overvoltage occurs, the disconnector connected in series between the metal oxide arrester and the cross arm can quickly and reliably disengage the faulty metal oxide arrester operation, and give a clear sign of disengagement, which is convenient for inspectors to find faulty arresters, and provides practical technical measures for the realization of "conditional maintenance" of metal oxide arresters;

(5) The lightning arrester of the present utility model is easy to install and disassemble, and it is convenient to carry out the replacement operation without power failure of the system.

Description of drawings

Fig. 1 is a structural representation of the utility model;

Fig. 2 is a partial schematic diagram of the puncture clamping hardware.

Detailed ways

The following is a detailed description of the embodiments of the present utility model. This embodiment is implemented on the premise of the technical solution of the present utility model, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present utility model is not limited to the following the described embodiment.

As shown in Figure 1, this embodiment includes puncture clamping fittings 1, insulated wires 2, high-voltage electrode arc rods 3, post insulators 4, insulating brackets 5, crossarms 6, metal oxide arresters 7, disconnectors 8 and grounding Conductor 9; the puncture clamp fitting 1 is set on the top of the post insulator 4, the bottom end of the post insulator 4 is fixed on the cross arm 6, the puncture clamp fitting 1 clamps the insulated wire 2, the high voltage electrode arc rod 3 and the puncture The clamping fittings 1 are connected, the insulating support 5 is parallel to the high-voltage electrode arc striker 3, the insulating support 5 is respectively connected to the post insulator 4 and the metal oxide arrester 7, and the top of the metal oxide arrester 7 is provided with a semi-spherical electrode 71, a semi-spherical electrode 71 and the high-voltage electrode arc rod 3 form a fixed external series discharge gap, the disconnector 8 and the metal oxide arrester 7 are connected in series, and the ground terminal of the disconnector 8 and the crossarm 6 are connected to the ground through the grounding wire 9. The high voltage electrode arc rod 3 is coated with an insulating sleeve 31 .

As shown in Figure 2, the puncture clamping hardware 1 includes an insulating shield 11 and an upper pressing block 12, a lower pressing block 13, a connecting piece and spikes 14 arranged in the insulating shield 11, and the upper pressing block 12 is arranged on the lower pressing On the block 13, the upper pressing block 12 and the lower pressing block 13 are connected by a connecting piece, the thorns 14 are arranged symmetrically on the upper pressing block 12 and the lower pressing block 13, and the thorns 14 on the upper pressing block 12 and the lower pressing block The prongs 14 on the 13 clamp the insulated wires 2 respectively, the lower pressing block 13 is connected to the top of the post insulator 4, and the high-voltage electrode arc striking rod 3 is connected to the lower pressing block 13.

The connecting piece includes a bolt 15 and a torque nut 16 , the upper pressing block 12 and the lower pressing block 13 are sleeved on the bolt 15 respectively, and the torque nut 16 is screwed on the bolt 15 . The torque nut 16 is adopted, the pressing force is balanced and reliable, which meets the requirements of the current flow capacity, and at the same time does not damage the core wire, ensuring reliable long-term contact between the high-voltage puncture electrode and the core wire.

The thorns 14 are four-tooth stamped sheets made of copper alloy. The stamped sheet is thin and slender, with blunt teeth, higher strength and toughness than aluminum alloy, and better electrical conductivity. Considering that the copper-aluminum alloy is easily oxidized during transition, an anti-oxidation layer is provided on the surface of the teeth 14 .

The disconnector 8 is connected in series with the lower end of the metal oxide arrester 7 through a threaded external interface, so as to realize reliable serial connection between the disconnector 8 and the metal oxide arrester 7 .

The disconnector 8 is a thermal explosion type with strong impact resistance, and will not act under the impact of a 2ms square wave or a 4/10μs high current.

The ground wire 9 is copper multi-strand flexible wire with a cross-sectional area greater than 10 mm ² , so that the disconnector 8 can move freely and form a sufficient air gap to reliably isolate the damaged lightning arrester from the system.

When this embodiment is working, when the magnitude of the lightning voltage on the insulated conductor 2 exceeds the gap discharge voltage, the series gap formed by the high-voltage electrode arc rod 3 and the semi-spherical electrode 71 breaks down. When the metal oxide arrester 7 works normally, the disconnector 8 does not operate and presents low impedance, and the metal oxide arrester 7 enters a low-impedance conduction state, which plays a role in limiting the overvoltage at both ends of the post insulator 4. After the lightning strikes, the system When the working voltage is applied to the metal oxide arrester 7, the metal oxide arrester 7 instantly returns to the high-impedance blocking state, the power frequency freewheeling is suppressed within a small range and the arc cannot be established, the insulation performance of the series gap recovers rapidly, and the metal oxide The physical lightning arrester 7 and the line return to normal operation; when the metal oxide lightning arrester 7 is damaged and fails, the power frequency fault current passes through the disconnector 8, and the disconnector 8 operates in a timely, accurate and reliable manner, so that the faulty metal oxide lightning arrester 7 is disconnected from operation, And there is an obvious breakaway sign, which is convenient for inspectors to find the faulty metal oxide arrester 7 .

Claims (9)

1. An integrated fixed external series gap self-detachment metal oxide arrester insulator, characterized in that it includes puncture clamping fittings (1), insulated wires (2), high-voltage electrode arc rods (3), post insulators (4 ), insulating support (5), cross arm (6), metal oxide arrester (7), disconnector (8) and grounding wire (9); the puncture clamp fitting (1) is set on the post insulator (4) The top end of the post insulator (4) is fixed on the cross arm (6), the piercing and clamping fitting (1) clamps the insulated wire (2), the high-voltage electrode arc striking rod (3) and the piercing and clamping fitting (1 ), the insulating support (5) is parallel to the high-voltage electrode arc rod (3), the insulating support (5) is respectively connected to the post insulator (4) and the metal oxide arrester (7), and the top of the metal oxide arrester (7) is set There are semi-spherical electrodes (71), semi-spherical electrodes (71) and high-voltage electrode arc strikers (3) to form a fixed external series discharge gap, disconnectors (8) and metal oxide arresters (7) are connected in series, disconnectors (8 ) and the cross arm (6) are connected to the ground through the ground wire (9). 2. The integrated fixed external series gap self-detachment metal oxide arrester insulator according to claim 1, characterized in that the piercing and clamping hardware (1) includes an insulating shield (11) and is arranged on the insulating shield ( 11) the upper pressing block (12), the lower pressing block (13), the connector and the thorns (14), the upper pressing block (12) is arranged on the lower pressing block (13), the upper pressing block (12) and The lower pressing block (13) is connected by a connecting piece, the thorns (14) are symmetrically arranged on the upper pressing block (12) and the lower pressing block (13), the thorns (14) on the upper pressing block (12) and the The teeth (14) on the lower pressing block (13) hold the insulated wires (2) respectively, the lower pressing block (13) is connected to the top of the post insulator (4), the high-voltage electrode arc rod (3) and the lower pressing block (13) CONNECTED. 3. The integrated fixed external series gap self-disengaging metal oxide arrester insulator according to claim 2, characterized in that, the connecting parts include bolts (15) and torque nuts (16), the upper pressing block (12) and The lower pressing blocks (13) are sleeved on the bolts (15) respectively, and the torque nuts (16) are screwed on the bolts (15). 4. The integrated fixed external series gap self-detachment metal oxide arrester insulator according to claim 2, characterized in that the thorns (14) are four-tooth stamped pieces made of copper alloy. 5. The integrated fixed external series gap self-detachment metal oxide arrester insulator according to claim 4, characterized in that the surface of the thorn (14) is provided with an anti-oxidation layer. 6. The integrated fixed external series gap self-detachment metal oxide arrester insulator according to claim 1, characterized in that the detachment device (8) is connected to the lower end of the metal oxide arrester (7) through a threaded external interface in series. 7. The integrated fixed external series gap self-detachment metal oxide arrester insulator according to claim 1, characterized in that the detachment device (8) is a heat-melt or thermal-explosion type. 8 . The integrated fixed external series gap self-detachment metal oxide arrester insulator according to claim 1 , characterized in that an insulating sleeve ( 31 ) is covered on the high voltage electrode arc striking rod ( 3 ). 9. The integrated fixed external series gap self-detachment metal oxide arrester insulator according to claim 1, characterized in that the grounding wire (9) is a copper multi-strand flexible wire with a cross-sectional area greater than 10 mm ² .

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