Power transmission line assembly for improving transmission capacity

Abstract

The invention discloses a power transmission line assembly for improving transmission capacity, which comprises a capacity-increasing wire and a novel wire clamp, and is characterized in that the cross section of the capacity-increasing wire is circular, the capacity-increasing wire comprises a steel core layer and a stranded wire layer, the steel core layer is an aluminum-clad invar steel core, and the aluminum-clad invar steel core is formed by concentrically stranding a plurality of aluminum-clad invar steel wires; the stranded wire layer is concentrically stranded with a plurality of layers of heat-resistant aluminum alloy wires outside the steel core layer, the stranding directions are alternate and reverse, and the outer surface of the novel wire clamp is made of high-conductivity aluminum alloy. The novel aluminum-clad invar steel core heat-resistant aluminum stranded wire is adopted to replace an original common steel core aluminum stranded wire, and the through-current capacity of the wire is improved. The steel core of the wire is designed into the aluminum-clad invar steel core, the mechanical strength of the steel core is greatly improved, and the wire has a better temperature sag characteristic, that is, after the operating temperature of the wire is increased, the gravity of the wire is completely borne by the invar steel core, and the problem that the sag of the wire is increased due to the temperature rise of the steel core when large current passes through is well solved.

Description

Technical Field

[0001] The present invention relates to the field of power transmission lines, and in particular to a power transmission line component for improving transmission capacity. Background Art

[0002] With the economic development of coastal areas, the demand for electricity is also growing. If the capacity is expanded by building new lines or transmission lines, large areas of land will be required, which will to a certain extent damage the ground vegetation and occupy arable land. In addition, the one-time investment is large and not conducive to environmental protection. There are also problems such as difficulty in land acquisition for transmission corridors and high investment costs.

[0003] The current power transmission system generally adopts a steel-core aluminum stranded wire structure. Its outer layer is made of aluminum alloy material, which is mainly responsible for the conductive task. The internal steel core bears the gravity and tension of the conductor. Among the matching connecting hardware, traditional wire clamps are mostly made of cast iron. Although this system meets the basic power transmission needs, it presents systemic defects when carrying capacity expansion and upgrades.

[0004] Traditional steel-core aluminum stranded conductors can overheat when the current they transmit increases. This elevated temperature causes the conductors to stretch and sag, which not only reduces the distance between the conductors and the ground, potentially leading to discharges and seriously impacting power transmission safety, but also increases resistance and losses. Furthermore, when high currents are passed through the conductors, traditional wire clamps generate eddy current losses within the clamps. Summary of the Invention

[0005] In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a transmission line assembly with improved transmission capacity, thereby increasing the transmission capacity of the transmission line while reducing transmission losses.

[0006] The purpose of the present invention is achieved through the following technical solutions: A power transmission line assembly for increasing transmission capacity comprises a capacity-increasing conductor and a novel wire clamp. The capacity-increasing conductor has a circular cross-section and comprises a steel core layer and a stranded wire layer. The steel core layer is an aluminum-clad Invar steel core formed by concentrically twisting multiple aluminum-clad Invar steel wires. The stranded wire layer comprises several layers of heat-resistant aluminum alloy wires concentrically twisted outside the steel core layer, with the twisting directions alternating and reversed. The outer surface of the novel wire clamp is made of a high-conductivity aluminum alloy.

[0007] Preferably, the electrical conductivity of the heat-resistant aluminum alloy wire is 60.0% IACS.

[0008] Preferably, the heat-resistant aluminum alloy wire is an aluminum alloy wire that can withstand temperatures of 150-180°C.

[0009] Preferably, the aluminum-clad Invar steel wire is an Invar steel wire having an outer layer coated with an aluminum layer.

[0010] Preferably, the wire clamp adopts a bag-type structure.

[0011] Preferably, the thickness of the wire clamp is 8-10 mm.

[0012] The present invention has the following advantages and beneficial effects compared to the prior art: The present invention replaces conventional steel-core aluminum stranded wire with a new aluminum-clad Invar core heat-resistant aluminum stranded wire to increase the current carrying capacity of the conductor. The steel core of the conductor is designed as an aluminum-clad Invar core, which significantly increases its mechanical strength and provides better temperature sag characteristics. That is, when the conductor operating temperature rises, the weight of the conductor is completely borne by the Invar core, effectively resolving the problem of increased conductor sag caused by the increased temperature of the steel core when high current passes through it. The aluminum stranded wire on the conductor's exterior is designed as a heat-resistant aluminum alloy wire with a conductivity of 60.0% IACS, which significantly increases the conductor's conductivity, reduces conductor loss and heat generation, and controls the conductor's temperature rise. High-conductivity aluminum alloy wire clamps are used to match the new conductor. Due to the high conductivity and low resistance of aluminum, as well as its low magnetic permeability and low eddy current loss, the energy loss of the clamp itself can be greatly reduced, indirectly increasing the conductor's transmission capacity. This, in conjunction with the conductor assembly, achieves system capacity expansion. As the current carried by the conductor increases, the overall transmission capacity of the line increases. Simultaneously, due to changes in the material of the conductor's outer surface and the clamp, the clamp's energy consumption is reduced. The conductors and wire clamps work together to increase capacity and reduce losses to ensure efficient energy transmission of the conductor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of transmission line components to increase transmission capacity.

[0014] Figure 2 This is a schematic structural diagram of the capacity-increasing conductor of the present invention.

[0015] Figure 3 Graph showing the current density distribution of stranded wires made of different materials according to the present invention.

[0016] Figure 4 This is the sag-temperature characteristic diagram.

[0017] The markings of the components in the accompanying drawings are: 1-Increased capacity conductor, 2-New type of wire clamp, 3-Steel core layer, 4-Stranded wire layer. DETAILED DESCRIPTION

[0018] The purpose of the present invention is described in further detail below with reference to the accompanying drawings and specific examples. The examples cannot be described one by one here, but the implementation methods of the present invention are not limited to the following examples.

[0019] Example 1 A transmission line assembly for increasing transmission capacity includes a capacity-enhancing conductor and a novel cable clamp. The capacity-enhancing conductor comprises a steel core layer and a stranded wire layer. The conductor has a circular cross-section. The steel core layer is composed of seven concentrically stranded aluminum-clad Invar steel wires, each coated with an aluminum layer. The stranded wire layer consists of three layers of heat-resistant aluminum alloy wire, stranded in alternating directions, concentrically stranded outside the steel core. The heat-resistant aluminum alloy wire has a conductivity of 60.0% IACS and can withstand temperatures of 150-180°C. The stranded conductor, with multiple aluminum-clad steel wires as the reinforcement core and multiple layers of concentrically stranded heat-resistant aluminum alloy wire with a conductivity of 60.0% IACS, is constructed. Simulation calculations show that when high current is applied to the outermost heat-resistant aluminum alloy layer, the current is primarily distributed throughout the aluminum alloy layer, reducing the skin effect and achieving a more uniform current density distribution within the aluminum alloy portion. At the same time, the sag temperature characteristics of the aluminum-clad steel core conductor were verified through calculation and experiments. It was found that the sag basically stopped changing after reaching 95°C.

[0020] The new clamp's outer surface is made of high-conductivity aluminum alloy, adopts a bag-like structure, and is 10mm thick. Because the clamp is made of high-conductivity aluminum alloy, its losses are greatly reduced. The conductor and clamp work together to increase capacity and reduce losses, significantly improving the transmission efficiency of the conductor system.

[0021] Figure 3 is the current density distribution diagram of stranded wires of different materials, Figure 3 It can be seen that the current density of aluminum-clad steel core aluminum stranded wire is lower than that of aluminum alloy core aluminum stranded wire and aluminum alloy stranded wire, which can prevent the conductor from being stretched and the sag from increasing, which can easily cause discharge due to insufficient distance to the ground.

[0022] Figure 4 is the sag-temperature characteristic diagram, Figure 4 It can be seen that under the action of large current, the current of the outermost heat-resistant aluminum alloy is basically distributed on the aluminum alloy layer, the skin effect is weakened, the current density distribution of the aluminum alloy part is more uniform, and the sag basically does not change after reaching 95°C.

[0023] Example 2 Experimental research was conducted to measure the energy loss of cast iron and aluminum alloy clamps and the increased capacity conductors proposed in this application. Test circuits were established, one without a clamp, one with multiple cast iron clamps, and one with multiple high-efficiency alloy clamps. A 680A AC current was applied. The energy loss of each clamp was calculated by measuring the power difference between the clamps and the ones without.

[0024] Table 1

[0025] The test and calculation results are shown in Table 1. Compared with cast iron wire clamps, aluminum alloy wire clamps have lower losses. This is because aluminum alloy wire clamps can cooperate with the increased capacity conductors to increase capacity and reduce losses to jointly ensure efficient energy transmission of the conductor system.

[0026] The above specific implementation manner is a preferred embodiment of the present invention and does not limit the present invention. Any other changes or other equivalent replacement methods that do not deviate from the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. A power transmission line assembly for increasing transmission capacity, characterized in that: The invention comprises a capacity-increasing conductor (1) and a novel wire clamp (2), wherein the cross section of the capacity-increasing conductor (1) is circular, and the capacity-increasing conductor (1) comprises a steel core layer (3) and a stranded wire layer (4), wherein the steel core layer (3) is an aluminum-clad Invar steel core, and the aluminum-clad Invar steel core is formed by concentrically twisting a plurality of aluminum-clad Invar steel wires; the stranded wire layer (4) is a plurality of layers of heat-resistant aluminum alloy wires concentrically twisted outside the steel core layer (3), and the twisting directions are alternately reversed, and the outer surface of the novel wire clamp (2) is made of a high-conductivity aluminum alloy.

2. The power transmission line assembly for increasing transmission capacity according to claim 1, characterized in that: The electrical conductivity of the heat-resistant aluminum alloy wire is 60.0% IACS.

3. The power transmission line assembly for increasing transmission capacity according to claim 1, characterized in that: The heat-resistant aluminum alloy wire is an aluminum alloy wire with a temperature resistance of 150-180°C.

4. The power transmission line assembly for increasing transmission capacity according to claim 1, characterized in that: The aluminum-clad Invar steel wire is formed by coating an aluminum layer on the outer layer of the Invar steel wire.

5. The power transmission line assembly for increasing transmission capacity according to claim 1, characterized in that: The novel wire clamp (2) adopts a bag-type structure.

6. The power transmission line assembly for increasing transmission capacity according to claim 1, characterized in that: The thickness of the novel wire clamp (2) is 8-10 mm.

7. The power transmission line assembly for increasing transmission capacity according to claim 1, characterized in that: The thickness of the novel wire clamp (2) is 10 mm.

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