10kV power distribution network overhead insulated wire anti-breaking device

Abstract

The invention provides a 10kV power distribution network overhead insulated wire breakage prevention device. The 10kV power distribution network overhead insulated wire breakage prevention device comprises a lightning protection filter, an insulated wire guide binding wire and a 10kV insulated wire. The insulated wire guides the binding wire to be wound on the surface of an insulating layer of the 10kV insulated wire, and one end of the insulated wire is connected with the upper end of the lightning protection filter; and the lower end of the lightning protection filter is connected with a grounding grid through a ceramic resistor. According to the invention, the binding wire is guided to wind the surface of the insulating layer of the 10 kV overhead cable through the overhead insulated wire, so that the high-frequency component of lightning current is guided to be discharged from the filter preferentially, and the high-frequency component of the lightning current is absorbed through the bipolar plate effect in the filter and the high-frequency absorption effect of the barium titanate phase-change material. The high-current arc striking effect on the insulated wire under lightning stroke can be effectively improved, the wave head voltage of steep waves of lightning current is rapidly reduced, and lightning stroke trip-out faults caused by disconnection of the insulated wire of a distribution line and lightning stroke flashover under lightning stroke are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of lightning protection for power distribution networks, and in particular relates to a device for preventing overhead insulated conductors from breaking in a 10kV distribution network. Background Art

[0002] Insulated conductors for 10kV distribution lines are widely used in power systems because they can address the conflict between tree growth and contact discharge between conductors, particularly the significant challenge of urban landscaping, power line corridors, and the safe operation of power lines. However, they also have a fatal weakness: when subjected to atmospheric overvoltage (lightning) discharge, they are highly susceptible to disconnection. This can severely impact the stable operation of the power system and, more importantly, the safety of nearby personnel. During a lightning strike, the breakdown point is very small, preventing the arc from migrating. This causes a very high temperature at this point, and the instantaneous high temperature melts the aluminum metal at this point, causing the conductor to break. Current protection methods include installing zinc oxide arresters, discharge gaps, lightning conductors, or coupled ground wires on medium-voltage insulated conductors to prevent disconnection from atmospheric overvoltage. However, these methods are less than ideal, and disconnection accidents often occur.

[0003] At present, the traditional use of puncture wire clamps and the addition of electrical protection gaps has the main problem that after the discharge protection gap is installed, the direction of the electrode of the discharge protection gap (when newly installed, it is vertical to the ground, and it will change to the horizontal direction after operation) will change due to the change in the stress on the insulated wire. This will directly affect its protection performance and in severe cases, it will lose its protection function. In addition, some single discharge protection gaps may cause the power frequency continuous current capacity to fail to meet the requirements of the fault current due to reasons such as materials or processes. This will also cause accidents in which the insulated wire breaks after being subjected to lightning overvoltage. Therefore, the present invention is very necessary to improve the lightning protection ability of the insulated wire and ensure the safe and stable operation of the power grid with new and effective lightning protection measures.

[0004] Problems with existing technology: Current lightning protection systems install protective gaps and arresters on the busbar behind insulated conductors. However, when lightning overvoltage is very high, the lightning charge can flash over the insulator to ground before reaching the protective gap, causing a power-frequency short circuit and a wire break. Therefore, it is essential to absorb the lightning charge energy on the surface of the insulated conductor. Summary of the Invention

[0005] The object of the present invention is to provide a 10kV distribution network overhead insulated conductor anti-breaking device.

[0006] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0007] A 10kV distribution network overhead insulated conductor disconnection prevention device comprises a lightning protection filter, an insulated conductor guide binding wire, and a 10kV insulated conductor; the insulated conductor guide binding wire is wound around the surface of the insulation layer of the 10kV insulated conductor, with one end connected to the upper end of the lightning protection filter; the lower end of the lightning protection filter is connected to the grounding grid via a ceramic resistor; the lightning protection filter comprises a double-layer discharge plate with a gap, an inner cavity insulating cylinder, and a pilot maintaining rope; and the lightning protection filter is filled with barium titanate phase change material.

[0008] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0009] As a preferred technical solution of the present invention, the double-layered gap discharge plate consists of two perforated metal plates, supported by insulated screws and spaced 20 to 50 mm apart. The upper metal plate is connected to the overhead conductor, while the lower metal plate is connected to the insulating rope of the inner cavity insulating cylinder. The gap between the two perforated metal plates is determined according to the discharge distance of different voltage levels. The metal plates are made of corrosion-resistant stainless steel.

[0010] As a preferred technical solution of the present invention: the inner cavity type insulating column is made of composite insulating material, with a cavity in the middle and an insulator umbrella skirt on the outer surface; the upper end of the inner cavity type insulating column is provided with an entry hole opening, and the lower end of the inner cavity type insulating column is provided with a drainage hole.

[0011] As a preferred technical solution of the present invention: the lightning protection filter further comprises a porous water seepage plate, which is a metal porous cover plate, and the porous water seepage plate is arranged on the top of the inner cavity type insulating column.

[0012] As a preferred technical solution of the present invention: the porous water-permeable plate is a corrosion-resistant stainless steel plate, aluminum plate or hot iron zinc plate.

[0013] As a preferred technical solution of the present invention: the leading maintaining rope is a high temperature resistant rope made of arc resistant asbestos fibers.

[0014] As a preferred technical solution of the present invention: the insulated wire guide wrapping wire is an aluminum wrapping tape, the upper end of the insulated wire guide wrapping wire is wrapped around the surface of the insulation layer of the insulated wire, the winding length is about 1.5 to 3 meters, and it is welded and reinforced with a glue gun, and the lower end of the insulated wire guide wrapping wire is connected to the lightning protection filter.

[0015] As a preferred technical solution of the present invention: the ceramic resistor is a 10-50 kΩ resistor, the upper end of which is connected to the lightning protection filter, and the lower end is connected to the grounding grid.

[0016] The present invention uses a lightning protection filter device and a ceramic resistor, and guides a binding wire to be wrapped around the insulation layer surface of a 10kV overhead cable through an overhead insulated conductor to guide the high-frequency component of the lightning current to preferentially discharge from the filter. The bipolar plate effect inside the filter is utilized, and the high-frequency absorption effect of the barium titanate phase change material is combined to effectively improve the large current arcing effect on the insulated conductor under lightning strikes, so that the wave head voltage of the lightning current steep wave drops rapidly, thereby reducing lightning tripping faults caused by disconnection of the insulated conductors of the distribution line and lightning flashover under lightning strikes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a scene diagram of the 10kV distribution network overhead insulated conductor anti-breakage device provided by the present invention.

[0018] Figure 2a This is the main view of the lightning protection filter.

[0019] Figure 2b This is a cross-sectional view of a lightning protection filter.

[0020] Figure 2c This is a bottom view of the lightning protection filter. DETAILED DESCRIPTION

[0021] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] A 10kV distribution network overhead insulated conductor disconnection prevention device comprises a lightning protection filter 1, an insulated conductor guide binding wire 2, and a 10kV insulated conductor 3; the insulated conductor guide binding wire 2 is wound around the surface of the insulation layer of the 10kV insulated conductor 3, and one end of the insulated conductor guide binding wire 2 is connected to the upper end of the lightning protection filter 1; the lower end of the lightning protection filter 1 is connected to the grounding grid via a ceramic resistor 4.

[0023] The lightning protection filter 1 is composed of a double-layer discharge plate with a gap, an inner cavity type insulating cylinder, and a pilot maintaining rope. The lightning protection filter 1 is filled with barium titanate phase change material.

[0024] The double-layer gap discharge plate consists of two perforated metal plates of a certain area, supported by insulating screws between the metal plates, with a distance of about 20 to 50 mm. The upper end of the metal plate is connected to the overhead conductor, and the lower end is connected to the insulating rope of the inner cavity insulating column.

[0025] The inner cavity insulating column has a central cavity and an outer insulator shed. Made of composite insulating material, it features an inlet opening at the top and drainage holes at the bottom. The porous seepage plate is a metal perforated cover plate, installed on top of the inner cavity insulating column. The metal material is corrosion-resistant stainless steel, aluminum, or hot-dip galvanized steel.

[0026] The bimetallic gap consists of two metal electrodes fixed at the upper and lower ends of the column cavity. The gap is determined according to the discharge distance of different voltage levels, and the electrode material is corrosion-resistant stainless steel plate.

[0027] The lead maintenance rope is a high temperature resistant rope made of arc resistant asbestos fiber.

[0028] The insulated wire guide wrapping wire 2 is an aluminum wrapping tape. The upper end of the conductor is wrapped around the surface of the insulation layer of the insulated wire. The wrapping length is about 1.5 to 3 meters. It is welded and reinforced with a glue gun. The lower end is connected to the lightning protection filter 1.

[0029] The ceramic resistor is a 10-50 kΩ resistor, the upper end of which is connected to the lightning protection filter 1 device, and the lower end is connected to the grounding grid.

[0030] The lightning protection filter 1 includes a double-layer gap discharge plate, a capacitive bipolar plate stacked inside an insulating seal and installed facing each other, and the bipolar plates can absorb "rainwater" from rainy days. The insulating sealed container is a sealed tank container made of a composite insulating material, and a combination of calcium titanate particles and titanium dioxide containing polar media and high dielectric constant is added to the container.

[0031] A suspension is formed in the liquid phase of rainwater during thunderstorms using a phase-change material formula. Since the magnetic permeability of the particles is different from that of the base liquid, the particles will be excited under the action of an external electric field. The polarization of the magnetorheological fluid can also be approximated by a magnetic dipole model. If the force between the dipoles is strong enough, the particles will aggregate into chains and may further form columns or other structures, resulting in solid-liquid phase separation. This structural change causes a huge change in the viscosity of the suspension. This change process includes the absorption and loss of energy, which can be completed in the instantaneous absorption of a pulse of lightning energy (on the order of milliseconds), and is reversible and has good repeatability.

[0032] The design of an inner cavity insulating column with a built-in inner cavity greatly reduces the high-frequency impedance by the rainwater column accumulated after being wetted during thunderstorms, thereby reducing the discharge voltage value of the original gap lightning arrester under lightning strike environment, thereby effectively improving the volt-second characteristic curve of the lightning leader inducer, and significantly reducing the lightning flashover and lightning tripping rate of line insulators under thunderstorms.

[0033] The lightning protection filter 1 comprises a bipolar discharge gap, drainage holes, an inner cavity-type insulating cylinder with a built-in cavity in the center, and a porous water-permeable plate mounted on the top of the inner cavity-type insulating cylinder. Compared to existing technologies, the lightning filter significantly reduces high-frequency impedance by coupling the rainwater column formed during a thunderstorm with phase-change calcium titanate particles. Furthermore, the filter's polar dielectric converts lightning energy, reducing the discharge voltage of conventional gap-type puncture devices. This allows for a breakdown voltage lower than the impulse voltage of the insulator string, resolving the issue of insulated conductor breakage caused by the long air gap in conventional series-gap zinc oxide arresters.

[0034] The above-mentioned specific implementation methods are used to illustrate the present invention and are only preferred embodiments of the present invention, rather than limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit of the present invention and the scope of protection of the claims shall fall within the scope of protection of the present invention.

Claims

1. A 10kV distribution network overhead insulated conductor anti-breakage device, characterized by: Includes lightning protection filter, insulated conductor guide wire and 10kV insulated conductor; The insulated wire guide binding wire is wound around the surface of the insulation layer of the 10kV insulated wire, and one end is connected to the upper end of the lightning protection filter; The lower end of the lightning protection filter is connected to the grounding grid via a ceramic resistor; The lightning protection filter comprises a double-layer discharge plate with a gap, an inner cavity type insulating cylinder and a pilot maintenance rope; The lightning protection filter is filled with barium titanate phase change material.

2. The 10kV distribution network overhead insulated conductor anti-breakage device according to claim 1, characterized in that: The double-layer discharge plate with a gap is composed of two perforated metal plates, which are supported by insulating screws and are 20 to 50 mm apart. The upper metal plate is connected to the overhead conductor, and the lower metal plate is connected to the insulating rope of the inner cavity type insulating column.

3. The 10kV distribution network overhead insulated conductor anti-breakage device according to claim 1, characterized in that: The inner cavity type insulating column is made of composite insulating material, with a cavity in the middle and insulator sheds on the outer surface; An entrance hole is provided at the upper end of the inner cavity type insulating column, and a drainage hole is provided at the lower end of the inner cavity type insulating column.

4. The 10kV distribution network overhead insulated conductor anti-breakage device according to claim 1, characterized in that: The lightning protection filter further comprises a porous water seepage plate, which is a metal porous cover plate and is arranged on the top of the inner cavity type insulating column.

5. The 10kV distribution network overhead insulated conductor anti-breakage device according to claim 4, characterized in that: The porous water-permeable plate is a corrosion-resistant stainless steel plate, aluminum plate or hot iron zinc plate.

6. The 10kV distribution network overhead insulated conductor anti-breakage device according to claim 1, characterized in that: The leading maintenance rope is a high temperature resistant rope made of arc resistant asbestos fibers.

7. The 10kV distribution network overhead insulated conductor anti-breakage device according to claim 1, characterized in that: The insulated wire guide wrapping wire is an aluminum wrapping tape, and the upper end of the insulated wire guide wrapping wire is wound around the surface of the insulation layer of the insulated wire, with a winding length of 1.5 to 3 meters.

8. The 10kV distribution network overhead insulated conductor anti-breakage device according to claim 1, characterized in that: The ceramic resistor is a resistor of 10-50 kΩ.

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