CN205646435U - Built on stilts insulated wire prevents lightning -caused breaking device based on electrode implosion formula - Google Patents

Abstract

The utility model relates to an electrode implosion-based anti-lightning breakage device for overhead insulated wires, which comprises a closed insulating cover, an overhead insulated wire, a post insulator and a cross-arm, and is characterized in that the insulating protection on the post insulator and the cross-arm Air gaps are left between the sleeves, circular electrodes are arranged in each low-voltage electrode mounting bracket installed on the insulating sleeves, and explosives are arranged between each circular electrode. When the overhead insulated conductor is subjected to lightning overvoltage, the lightning flashover channel is dredged to the load side of the insulator string, and the power frequency short-circuit arc is cut off within tens of milliseconds by detonating the explosive inside the electrode, so as to achieve the purpose of deeply suppressing the lightning breakage of the overhead insulated conductor . The process is simple, the operability is strong, and the cost is low, and it is suitable for large-scale popularization and application.

Description

Lightning breakage protection device for overhead insulated conductors based on electrode implosion

technical field

The utility model belongs to the field of electrical engineering distribution networks, and relates to high-voltage electrical equipment, in particular to an electrode implosion-based overhead insulated wire anti-lightning strike disconnection device.

Background technique

With the further improvement of power users' requirements for power supply reliability, overhead insulated conductors are widely used in the field of distribution networks because of their strong resistance to external damage, no pollution flashover, and ice-covered flashover. The ability of overhead insulated wires to resist lightning overvoltage damage severely restricts their popularization and use in heavy minefields due to their inherent characteristics. It is a small pinhole, and the pinhole position is randomly distributed near the two sides of the line insulator. After the lightning flashover, the continuous power frequency short-circuit current will start arcing and burning along the lightning discharge channel, and the arc root at the high voltage end is always at the pinhole. Although it is affected by the electromagnetic force, it is fixed at the pinhole position due to the blocking of the insulating layer. This is obviously different from the overhead line using bare conductors. After the latter strikes and flashovers, the power frequency continuous flow arcs and burns. Under the action of electromagnetic power, the arc root can move along the conductor surface toward the direction of the load current flow until the arc When extinguished, the arc root will not be fixed at a point on the wire.

When a lightning strike causes a two-phase or three-phase-to-ground short circuit in the line, one situation is that the phase-to-phase arc passes through the cross-arm; the other situation is that the phase-to-phase arc is under the action of electromagnetic force and thermal stress, and the arc belly moves to the load side of the insulator. Drifting in the air, intersecting in the air may develop into an interphase arc, but the root of the arc is always fixed at the perforation position. The magnitude of the phase-to-phase short-circuit current is as high as several thousand amperes to more than ten thousand amperes, and the temperature of the arc root rises to thousands of degrees Celsius. Coupled with the tension generated by the wire's own weight, the core wire melts and disconnects instantly. Even if the lightning strike only causes a single phase-to-ground short circuit of the insulated line, when the distribution network adopts the neutral point effective grounding method, it is allowed to operate with a single-phase ground fault for a period of time, and the same position of the wire will be damaged by the small current arc burning the wire for a long time. Disconnected.

To sum up, the root cause of the disconnection of overhead insulated conductors is the power frequency freewheeling arc after lightning flashover. At present, the lightning protection of overhead insulated conductors mainly adopts blocking and dredging methods. But there are certain shortcomings:

(1) The plugging method is realized by strengthening the line insulation, erecting lightning protection lines and installing metal oxide arresters. Engineering experience shows that the plugging lightning protection method not only has high engineering cost, but also has poor lightning protection effect;

(2) The dredge-type lightning protection method is realized by installing arc-proof fittings, discharge clamp insulators and other measures. It increases the probability of lightning flashover by reducing the potential gradient of the discharge flashover channel, and the power frequency freewheeling arc extinguishing characteristic is poor. Cause its lightning protection breakage rate is still high not small, seriously restricting the popularization and use of overhead insulated conductors in heavy minefields.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art, and provide a method that can guide the lightning flashover channel to the load side of the insulator string when the overhead insulated conductor is subjected to lightning overvoltage, so as to protect the insulator string from being damaged by lightning impact. The function is based on the electrode implosion type overhead insulated wire lightning protection disconnection device.

The utility model solves the problems of the technologies described above by adopting the following technical solutions:

An electrode implosion-based anti-lightning disconnection device for overhead insulated wires, comprising a closed insulating cover, an overhead insulated wire, a post insulator and a cross arm, the closed insulating cover has a built-in overhead insulated wire connector, and the overhead insulated wire Crossing the upper end of the overhead insulated wire connector, the lower end of the overhead insulated wire connector is coaxially connected to the post insulator, and the lower right side of the overhead insulated wire connector is connected to a high-voltage electrode; the cross arm and the closed The insulating cover, the overhead insulated wire, the post insulator and the high-voltage electrode are arranged in the air, and the low-voltage electrode metal support is coaxially arranged on the cross-arm, and the insulating sheath is coaxially fixed on the low-voltage electrode metal support. There is an air gap between the sleeve and the post insulator, and three low-voltage electrode mounting brackets are inserted into one side of the insulating sheath, and a pair of circular electrodes is arranged in each low-voltage electrode mounting bracket. Explosives are arranged between the two circular electrodes.

Moreover, the lower end of the high-voltage electrode protrudes from the closed insulating cover and extends to one side of the post insulator.

Moreover, a low-voltage electrode metal support hoop is concentrically arranged on the low-voltage electrode metal support.

Moreover, the three low-voltage electrode mounting brackets are arranged at intervals on the same horizontal plane

Advantage and beneficial effect of the present utility model are:

1. The device of this utility model adopts a pure air gap, making full use of the better self-restoring insulation characteristics of air, and the main structure overhead insulated wire uses a line post composite insulator, and the discharge gap grounding electrode is composed of three metal tubes equipped with special explosives . Under laboratory conditions, conduct a discharge test to ensure that the discharge channel where the implosion electrode is installed is discharged preferentially; under harsh conditions such as pollution and humidity, conduct a discharge test to ensure that the parallel protection gap has a certain probability of preferential discharge; in the standard lightning current waveform The electrode equipped with explosives can detonate reliably under impact conditions, and has the function of cutting off the power frequency short-circuit arc for three times and suppressing lightning strike disconnection.

2. Since the discharge voltage of the discharge channel formed by the implosion function electrode is lower than the discharge voltage of the insulator string, if the lightning overvoltage exceeds the discharge voltage of the discharge channel, the discharge channel discharges and forms a flashover channel, which protects the insulator string and avoids burning of the insulator surface Eclipses and even explosions. After the flashover channel is formed, under the action of power frequency voltage, a power frequency short-circuit arc will be formed. The device of the utility model can detonate the internal explosive of the electrode by the lightning shock wave or the initial current of the short-circuit arc at the initial stage of the formation of the flashover channel, cut off the power-frequency short-circuit arc within tens of milliseconds, and achieve the purpose of deeply suppressing the breakage of the overhead insulated wire by lightning.

3. The utility model has simple manufacturing process, strong operability, simple installation method, low construction strength, can withstand lightning pulse discharge for many times, has the characteristics of repeated use, can effectively cut off the power frequency short-circuit arc channel, and has the ability to greatly reduce overhead The insulated wire has the function of lightning disconnection, and the cost is low, which is suitable for large-scale promotion and application.

Description of drawings

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

FIG. 2 is a top cross-sectional view of part A in FIG. 1 .

detailed description

The utility model is described in further detail below through specific examples, the following examples are only descriptive, not limiting, and cannot limit the protection scope of the utility model with this.

An electrode implosion-based anti-lightning disconnection device for overhead insulated wires, as shown in FIG. An overhead insulated wire connector 2 is built in the closed insulating cover, and the overhead insulated wire crosses the upper end of the overhead insulated wire connector, and the lower end of the overhead insulated wire connector is coaxially connected to the post insulator, and the overhead insulated wire The lower right side of the connector is connected with a high-voltage electrode 4, and the lower end of the high-voltage electrode protrudes from the closed insulating cover and extends to one side of the post insulator. The cross-arm is set apart from the closed insulating cover, overhead insulated wires, post insulators and high-voltage electrodes, and a low-voltage electrode metal support 8 is coaxially arranged on the cross-arm, and a low-voltage electrode metal support 8 is concentrically arranged on the low-voltage electrode metal support. The electrode metal bracket hoop 6 is coaxially fixed with an insulating sheath 9 on the low-voltage electrode metal bracket, and an air gap is left between the insulating sheath and the post insulator. Three low-voltage electrode mounting brackets 5 are plugged into one side of the insulating sheath. As shown in Figure 2, the three low-voltage electrode mounting brackets are arranged at intervals on the same horizontal plane, and a low-voltage electrode mounting bracket is arranged in each low-voltage electrode mounting bracket. For the circular electrodes 11, an explosive 12 is arranged between each of the circular electrodes.

The working principle of the utility model:

The utility model constructs a novel anti-lightning disconnection device for overhead insulated wires based on electrode implosion type. The arc is generated by the air gap between the sleeves, and the arc ignites the explosive located between a pair of circular electrodes. After the explosive is detonated in the center, the detonation products drive the arc to the wall of the insulator, and compress the arc to extinguish it. In this process, the detonation products interact with the arc plasma, and the detonation products shunt the plasma arc compressed by the impact, resulting in the decrease of the arc conductivity with the expansion of the detonation products, and finally extinguished.

Since the discharge voltage of the discharge channel composed of electrodes with implosion function is lower than the discharge voltage of the insulator string, when the lightning overvoltage exceeds the discharge voltage of the discharge channel, the discharge channel is promoted to discharge, forming a flashover channel, protecting the insulator string and avoiding the ablation of the insulator surface Even explode. After the flashover channel is formed, under the action of power frequency voltage, a power frequency short-circuit arc will be formed. The principle of the utility model device is to detonate the internal explosive of the electrode by the lightning shock wave or the initial current of the short-circuit arc at the initial stage of the formation of the flashover channel, cut off the power frequency short-circuit arc within tens of milliseconds, and achieve the purpose of deeply suppressing the breakage of the overhead insulated conductor by lightning.

Claims (4)

1. An overhead insulated wire anti-lightning disconnection device based on electrode implosion type, comprising a closed insulating cover, an overhead insulated wire, a post insulator and a cross arm, characterized in that: said closed insulating cover has a built-in overhead insulated wire connector , the overhead insulated wire traverses the upper end of the overhead insulated wire connector, the lower end of the overhead insulated wire connector is coaxially connected to the post insulator, and the high voltage electrode is connected to the lower right side of the overhead insulated wire connector; The cross arm is set apart from the closed insulating cover, overhead insulated wires, post insulators and high-voltage electrodes, and a low-voltage electrode metal bracket is coaxially arranged on the cross-arm, and an insulating Sheath, there is an air gap between the insulating sheath and the post insulator, and three low-voltage electrode mounting brackets are inserted at one end of the insulating sheath, and a pair of circular electrode mounting brackets are arranged in each low-voltage electrode mounting bracket. Electrodes, explosives are arranged between each of the circular electrodes. 2. An electrode implosion-based anti-lightning disconnection device for overhead insulated wires according to claim 1, characterized in that: the lower end of the high-voltage electrode protrudes out of the closed insulating cover and extends to the One side of the post insulator. 3. An electrode implosion-based anti-lightning disconnection device for overhead insulated wires according to claim 1, characterized in that a low-voltage electrode metal support hoop is concentrically arranged on the low-voltage electrode metal support. 4. An electrode implosion-based anti-lightning disconnection device for overhead insulated wires according to claim 1, wherein the three low-voltage electrode mounting brackets are arranged at intervals on the same horizontal plane.