Overhead parallel bundled conductor
By optimizing the raw material ratio and modifying the insulation layer, the problems of insufficient insulation and heat dissipation of overhead parallel bundled conductors were solved, achieving higher insulation performance and heat dissipation effect, and improving safety and service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FEIHONG CABLE GRP CO LTD
- Filing Date
- 2025-07-11
- Publication Date
- 2026-05-29
Smart Images
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Abstract
Description
Technical Field
[0001] This application relates to the field of wire and cable technology, and more specifically, to an overhead parallel bundled conductor. Background Technology
[0002] Parallel bundled overhead conductors, also known as parallel bundled overhead insulated cables, are a new type of low-voltage overhead insulated cable. They typically consist of two, three, or four insulated conductors connected in parallel to form a conductor bundle. Due to their advantages such as low line reactance, small footprint, simple line structure, reduced risk of electric shock, convenient installation, and low overall cost, parallel bundled overhead insulated cables are widely used in low-voltage lines in rural areas, towns and villages, old urban areas, urban villages, residential communities, or areas with low commercial loads. With the launch of a new round of rural and urban power grid transformation, the State Grid Corporation of China has significantly increased its tender for parallel bundled overhead insulated cables.
[0003] However, existing overhead parallel bundled conductors have shortcomings in terms of insulation and heat dissipation. On the one hand, traditional insulation materials are prone to aging under long-term harsh environments, leading to a decline in insulation performance and increasing safety hazards such as leakage and short circuits. On the other hand, conductors generate heat during the transmission of electrical energy. If the heat cannot be dissipated in time, the conductor temperature will rise, accelerating the aging of the insulation layer, reducing the service life of the conductor, and even causing serious accidents such as fires. The shape characteristics of the bundled conductor structure make its heat dissipation worse than that of a single conductor.
[0004] In related technologies, to improve the heat dissipation of overhead parallel bundled conductors, a heat-dissipating coating is applied to the surface of the insulation layer to reduce the surface temperature through radiation. However, the coating has limited adhesion and is prone to peeling off due to long-term exposure to wind and rain, requiring regular maintenance. Furthermore, some coatings may react chemically with the insulation material, leading to a decrease in insulation performance. On the other hand, to improve the insulation of overhead parallel bundled conductors, a thicker insulation layer is wrapped around the conductor. While this directly increases the insulation withstand voltage rating, the thick insulation layer hinders heat dissipation, causing the conductor's operating temperature to rise and accelerating insulation aging. Summary of the Invention
[0005] To improve the insulation and heat dissipation of overhead parallel bundled conductors, this application provides an overhead parallel bundled conductor.
[0006] Firstly, this application provides an overhead parallel bundled conductor, which adopts the following technical solution:
[0007] An overhead parallel bundled conductor includes at least two conductors arranged side by side, with adjacent conductors fixedly connected to each other by connecting ribs; an insulating layer is provided on the outer wall of the conductors;
[0008] The insulating layer comprises the following raw materials in parts by weight: 80-100 parts cross-linked polyethylene, 0.5-1 part antioxidant, 0.5-1 part ultraviolet absorber, 3-5 parts nano magnesium oxide, 5-15 parts methyl vinyl silicone rubber, 4-10 parts flake boron nitride, and 1-2 parts silane coupling agent.
[0009] The insulation layer of the overhead parallel bundled conductor of this application comprises the following raw materials in parts by weight: 80-100 parts of cross-linked polyethylene, 0.5-1 parts of antioxidant, 0.5-1 parts of ultraviolet absorber, 3-5 parts of nano magnesium oxide, 5-15 parts of methyl vinyl silicone rubber, 4-10 parts of flake boron nitride, and 1-2 parts of silane coupling agent. Any value within the respective range can be selected, and it can improve the insulation and heat dissipation of the overhead insulated conductor.
[0010] By adopting the above technical solutions, the insulation layer uses cross-linked polyethylene as the main raw material, providing the basic mechanical strength and insulation properties of the insulation layer. Antioxidants prevent oxidation reactions in overhead insulated cables during processing and at high temperatures, improving the weather resistance of the sheath. UV absorbers absorb UV energy, preventing it from causing polymer molecular chain breakage, thus preventing sheath cracking and improving the sheath's weather resistance. Nano-magnesium oxide dispersed in methyl vinyl silicone rubber fills the molecular gaps, forming a "rigid insulating skeleton" and improving the insulation performance of overhead parallel bundled conductors. Plate-like boron nitride has high thermal conductivity, optimizing the heat dissipation path and improving the heat dissipation of overhead parallel bundled conductors. Furthermore, the plate-like boron nitride forms a parallel orientation in cross-linked polyethylene, hindering the straight-line penetration path of electrons. The low dielectric constant of plate-like boron nitride, coupled with weak van der Waals forces connecting the layers, makes it difficult for electrons to cross the interlayer barrier, further enhancing insulation. The addition of a silane coupling agent allows one end of its molecule to condense with the hydroxyl groups on the surface of nano-magnesium oxide and flake boron nitride, while the other end copolymerizes with the vinyl group of silicone rubber via peroxide initiation, thereby further improving the insulation performance of overhead parallel bundled conductors.
[0011] In addition, nano-magnesium oxide can fill the gaps between the lamellar boron nitride layers, reducing interface defects and making the insulation layer structure more compact, further improving the insulation effect. Moreover, the lamellar boron nitride provides a long-range heat conduction path, while nano-zinc oxide fills the short-range gaps. The combined effect of both improves the thermal conductivity of the overhead parallel bundled conductors, thereby further enhancing their heat dissipation.
[0012] Preferably, the insulating layer comprises the following raw materials in parts by weight: 85-95 parts cross-linked polyethylene, 0.7-0.9 parts antioxidant, 0.7-0.9 parts ultraviolet absorber, 3.5-4.5 parts nano magnesium oxide, 8-12 parts methyl vinyl silicone rubber, 5-7 parts flake boron nitride, and 1.3-1.8 parts silane coupling agent.
[0013] The insulation layer of this application uses 85-95 parts of cross-linked polyethylene, 0.7-0.9 parts of antioxidant, 0.7-0.9 parts of ultraviolet absorber, 3.5-4.5 parts of nano magnesium oxide, 8-12 parts of methyl vinyl silicone rubber, 5-7 parts of flake boron nitride, and 1.3-1.8 parts of silane coupling agent. Any value within the respective range can be selected, and it can improve the insulation and heat dissipation of overhead insulated conductors.
[0014] Preferably, the weight ratio of the nano-magnesium oxide to methyl vinyl silicone rubber is 1:(2-4).
[0015] By adopting the above technical solution and adjusting the weight ratio of nano-magnesium oxide to methyl vinyl silicone rubber, it is more conducive to the uniform dispersion of nano-magnesium oxide in methyl vinyl silicone rubber, thereby improving the insulation effect of nano-magnesium oxide and methyl vinyl silicone rubber in the insulation layer, and further improving the insulation performance of overhead parallel bundled conductors.
[0016] Preferably, the weight ratio of the nano-magnesium oxide to the flake boron nitride is 1:(1.3-1.7).
[0017] By adopting the above technical solution and adjusting the weight ratio of nano-magnesium oxide to sheet boron nitride, it is helpful for nano-magnesium oxide to uniformly fill the gaps between the sheet boron nitride layers, which can further improve the heat dissipation and insulation of overhead parallel bundled conductors.
[0018] Preferably, the nano-magnesium oxide is prepared through modification, specifically:
[0019] S1. Add stearic acid to an ethanol solution, stir and heat to 60-80℃ to prepare a stearic acid solution with a concentration of 10-20%;
[0020] S2. Dry the nano-magnesium oxide at 100-120℃ for 2-4 hours, add it to the stearic acid solution, stir at 600-800 rpm, ultrasonically disperse for 15-30 minutes with an ultrasonic power of 300-500W, heat to 80-100℃, stir at a constant temperature for 2-4 hours, cool, filter and wash, and vacuum dry to obtain the modified nano-oxidase.
[0021] By adopting the above technical solution, stearic acid is used to modify the surface of nano-magnesium oxide. The long-chain alkyl groups of stearic acid are grafted onto the surface of nano-magnesium oxide, which improves the compatibility between nano-magnesium oxide and various raw materials of the insulating layer. Furthermore, stearic acid molecules can also be physically adsorbed on the surface of nano-magnesium oxide through van der Waals forces, which further improves the dispersibility between nano-magnesium oxide and various raw materials of the insulating layer, thereby improving the heat dissipation and insulation of overhead parallel bundled conductors.
[0022] Preferably, the mass ratio of the nano-magnesium oxide to stearic acid is 1:(0.5-1.5).
[0023] By adopting the above technical solution and adjusting the mass ratio of nano-magnesium oxide to stearic acid, the modification effect of stearic acid can be further improved, thereby improving the heat dissipation and insulation of overhead parallel bundled conductors.
[0024] Preferably, the insulating layer further includes sheet-like aluminum nitride.
[0025] By adopting the above technical solution, lamellar aluminum nitride is added to the insulating layer, and lamellar boron nitride can be embedded in the gaps between the lamellar aluminum nitride layers. The complementary structure forms a continuous heat-conducting network, which can further improve the heat dissipation of the lamellar aluminum nitride. In addition, the difference in dielectric constant between lamellar aluminum nitride and lamellar boron nitride can form a gradient distribution, which can further improve the heat dissipation and insulation of overhead parallel bundled conductors.
[0026] Preferably, the weight ratio of the sheet-like aluminum nitride to the sheet-like boron nitride is 1:(1-2).
[0027] By adopting the above technical solution and adjusting the weight ratio of sheet aluminum nitride to sheet boron nitride, the heat dissipation and insulation properties of overhead parallel bundled conductors can be further improved.
[0028] In summary, this application includes at least one of the following beneficial technical effects:
[0029] 1. This application improves the insulation performance and heat dissipation of overhead parallel bundled conductors by controlling the types and dosages of various raw materials in the insulation layer, resulting in thermal conductivity of 0.48 W / mk, volume resistivity at 20℃ of 2.28-2.31 Ω·cm, and dielectric strength of 35 MPa, respectively, and a reduction rate of elongation at break after thermal aging of 6.4-6.7%.
[0030] (2) This application modifies the nano-magnesium oxide in the insulating layer material and controls the mass ratio of nano-magnesium oxide to stearic acid, so that the thermal conductivity, volume resistivity at 20℃ and dielectric strength of the overhead parallel bundled conductor are 0.51-0.52W / mk, 2.37-2.40Ω·cm and 37MPa, respectively, and the elongation at break after thermal aging is reduced by 5.8-6.1%, which further improves the insulation performance and heat dissipation of the overhead parallel bundled conductor.
[0031] (3) This application improves the insulation performance and heat dissipation of overhead parallel bundled conductors by adding flake aluminum nitride to the insulating material and adjusting its weight ratio with flake boron nitride. The thermal conductivity, volume resistivity at 20℃ and dielectric strength are 0.58-0.60 W / mk, 2.47-2.56 Ω·cm and 40 MPa, respectively, and the elongation at break after thermal aging is reduced by 5.0-5.3%. Detailed Implementation
[0032] The present application will be further described in detail below with reference to specific embodiments.
[0033] The following raw materials used in this application are all commercially available products and are intended to fully disclose the raw materials used in this application. They should not be construed as limiting the source of the raw materials. Specifically: cross-linked polyethylene, brand Unica Japan, grade HFDJ-4201S MI3, purchased from Shanghai Oushuo Plastics Co., Ltd.; antioxidant, model 1010; ultraviolet absorber, model UV384-2, with an effective ingredient content of 95%; nano magnesium oxide, with a particle size of 50nm; methyl vinyl silicone rubber, with a vinyl content of 0.16% and an effective ingredient content of 98%; flake boron nitride, with a flake diameter of 1-3μm and an average thickness of <100nm; silane coupling agent, model KH550; stearic acid, with an effective ingredient content of 99%; flake aluminum nitride, with a flake diameter of 1-3μm and an average thickness of <100nm.
[0034] The following are examples of the preparation of modified nano-magnesium oxide.
[0035] Preparation Example 1
[0036] The modified magnesium oxide nanoparticles of Example 1 were prepared by the following steps:
[0037] S1. Add 0.3 kg of stearic acid to a 75% ethanol solution, stir and heat to 70°C to prepare a 15% stearic acid solution; S2. Dry 1 kg of nano-magnesium oxide at 110°C for 3 h, add it to the stearic acid solution, stir at 700 rpm, ultrasonically disperse for 20 min with an ultrasonic power of 400 W, heat to 90°C, stir and react at a constant temperature for 3 h, cool, filter and wash, and vacuum dry to obtain the modified nano-oxidase.
[0038] Preparation Examples 2-5
[0039] The modified silicon nitride in Preparation Examples 2-5 was prepared in the same way as in Preparation Example 1, except that the amount of stearic acid used was 0.5 g, 1 kg, 1.5 kg and 1.6 kg, respectively, while the types and amounts of other raw materials were the same as in Preparation Example 1.
[0040] Example 1
[0041] The overhead parallel bundled conductor of Example 1 was prepared by the following method:
[0042] According to the dosage in Table 1, the raw materials of the insulation layer are mixed at 120℃ for 15 minutes, extruded (zone 1 temperature is 150℃, zone 2 temperature is 170℃, zone 3 temperature is 160℃), and vulcanized at 140℃ for 10 minutes to obtain the insulation layer material.
[0043] Aluminum monofilaments are drawn, annealed, and then twisted to form conductors. Insulation material is extruded and coated onto the surface of the conductors, which are then cross-linked by irradiation for 2-4 hours. Adjacent conductors are fixed together by connecting ribs to obtain overhead parallel bundled conductors.
[0044] Examples 2-5
[0045] The overhead parallel bundled conductors in Examples 2-5 are the same as those in Example 1, except that the dosage of each raw material in the insulation layer is different, as detailed in Table 1.
[0046] Table 1. Raw material dosage (kg) for the insulating layers in Examples 1-5
[0047]
[0048] Examples 6-10
[0049] The overhead parallel bundled conductors in Examples 6-10 are the same as those in Example 1, except that the dosage of each raw material in the insulation layer is different, as detailed in Table 2.
[0050] Table 2. Raw material dosage (kg) for insulation layers in Examples 1-5
[0051]
[0052] Examples 11-15
[0053] The preparation method of the overhead parallel bundled conductors in Examples 11-15 is the same as that in Example 8, except that the nano-magnesium oxide is the modified nano-magnesium oxide prepared in Examples 1-5, and the other raw materials and dosages are the same as in Example 8.
[0054] Examples 16-20
[0055] The preparation methods of the overhead parallel bundled conductors in Examples 16-20 are the same as those in Example 13, except that the insulating material also includes sheet aluminum nitride, and the amount of sheet aluminum nitride used is 12kg, 6kg, 4kg, 3kg and 2.4kg respectively. The types and amounts of other raw materials are the same as those in Example 13.
[0056] Comparative Example 1
[0057] The overhead parallel bundled conductor of Comparative Example 1 is the same as that of Example 1, except that no nano-magnesium oxide is added to the insulation layer, while the other raw materials and dosages are the same as those of Example 1.
[0058] Comparative Example 2
[0059] The overhead parallel bundled conductor of Comparative Example 2 is the same as that of Example 1, except that methyl vinyl silicone rubber is not added to the insulation layer, while the other raw materials and dosages are the same as those of Example 1.
[0060] Comparative Example 3
[0061] The overhead parallel bundled conductor of Comparative Example 3 is the same as that of Example 1, except that no sheet boron nitride is added to the insulation layer, while the other raw materials and dosages are the same as those of Example 1.
[0062] Performance Testing (Part 1)
[0063] The performance of the overhead parallel bundled conductors obtained in different Examples 1-20 and Comparative Examples 1-3 was tested respectively. The test results are detailed in Table 3.
[0064] Thermal conductivity: The thermal conductivity of the insulation layer of overhead parallel bundled conductors was tested according to GB / T 10297-1998 "Determination of thermal conductivity of non-metallic solid materials by hot wire method".
[0065] Retention rate after thermal aging: The reduction rate of elongation at break after thermal aging of the insulation layer of overhead parallel bundled conductors was tested according to GB / T2951.12-2008.
[0066] Volume resistivity at 20℃: The volume resistivity of the insulation layer of overhead parallel bundled conductors at 20℃ was tested according to GB / T1410 standard.
[0067] Dielectric strength: The dielectric strength of the insulation layer of overhead parallel bundled conductors is tested in accordance with GB / T1409 standard.
[0068] Table 3 Performance test results of different overhead parallel bundled conductors
[0069]
[0070]
[0071] The test results in Table 3 show that the overhead parallel bundled conductor obtained in this application has a thermal conductivity as high as 0.60 W / mK, and the reduction rate of elongation at break after thermal aging is as low as 5.0%, which improves the heat dissipation of the overhead parallel bundled conductor. The highest volume resistivity and dielectric strength at 20℃ are 2.56 × 10⁻⁶. 14 The insulation performance of overhead parallel bundled conductors is improved by Ω·cm and 40kV / mm.
[0072] Based on the performance test data of the overhead parallel bundled conductors in Examples 1-5, it can be seen that the thermal conductivity, volume resistivity at 20℃, and dielectric strength of the overhead parallel bundled conductors in Examples 2-4 are 0.4-0.3 W / mk, 2.15-2.22 Ω·cm, and 32-33 MPa, respectively, which are all higher than those in Examples 1 and 5. Moreover, the reduction rate of elongation at break after thermal aging is 7.0-7.3%, which is lower than that in Examples 1 and 5. This indicates that the weight ratio of nano-magnesium oxide to methyl vinyl silicone rubber in the insulation layer material is more suitable, which improves the insulation performance and heat dissipation of the overhead parallel bundled conductors.
[0073] Based on the performance test data of the overhead parallel bundled conductors in Examples 6-10, it can be seen that the thermal conductivity, volume resistivity at 20℃, and dielectric strength of the overhead parallel bundled conductors in Examples 7-9 are 0.48 W / mk, 2.28-2.31 Ω·cm, and 35 MPa, respectively, which are all higher than those in Examples 6 and 10. Moreover, the reduction rate of elongation at break after thermal aging is 6.4-6.7%, which is lower than that in Examples 6 and 10. This indicates that a weight ratio of nano-magnesium oxide to flake boron nitride in the insulating layer material of 1:(1.3-1.7) is more suitable, which improves the insulation performance and heat dissipation of the overhead parallel bundled conductors.
[0074] Based on the performance test data of the overhead parallel bundled conductors in Examples 11-15, it can be seen that the thermal conductivity, volume resistivity at 20℃, and dielectric strength of the overhead parallel bundled conductors in Examples 12-14 are 0.51-0.52 W / mk, 2.37-2.40 Ω·cm, and 37 MPa, respectively, which are all higher than those in Examples 11 and 15. Moreover, the reduction rate of elongation at break after thermal aging is 5.8-6.1%, which is lower than that in Examples 11 and 15. This indicates that when modifying nano zinc oxide, a mass ratio of nano magnesium oxide to stearic acid of 1:(0.5-1.5) is more suitable, which improves the insulation performance and heat dissipation of the overhead parallel bundled conductors.
[0075] Based on the performance test data of the overhead parallel bundled conductors in Examples 16-20, it can be seen that the thermal conductivity, volume resistivity at 20℃, and dielectric strength of the overhead parallel bundled conductors in Examples 17-19 are 0.58-0.60 W / mk, 2.47-2.56 Ω·cm, and 40 MPa, respectively, which are all higher than those in Examples 6 and 10. Moreover, the reduction rate of elongation at break after thermal aging is 5.0-5.3%, which is lower than that in Examples 6 and 10. This indicates that the addition of flake aluminum nitride to the insulating material, and the optimal weight ratio of flake aluminum nitride to flake boron nitride of 1:(1-2), is more suitable, which improves the insulation performance and heat dissipation of the overhead parallel bundled conductors.
[0076] In addition, based on the performance test data of the overhead parallel bundled conductors in Comparative Examples 1-3 and Example 1, it was found that adding nano-magnesium oxide, methyl vinyl silicone rubber and flake boron nitride to the insulation layer material of the overhead parallel bundled conductor can improve the insulation performance and heat dissipation of the overhead parallel bundled conductor to varying degrees.
[0077] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. An overhead parallel bundled conductor, characterized in that, It includes at least two wires arranged side by side, and adjacent wires are fixedly connected to each other by connecting ribs; an insulating layer is provided on the outer wall of the wires; The insulating layer comprises the following raw materials in parts by weight: 80-100 parts cross-linked polyethylene, 0.5-1 parts antioxidant, 0.5-1 parts ultraviolet absorber, 3-5 parts nano magnesium oxide, 5-15 parts methyl vinyl silicone rubber, 4-10 parts flake boron nitride, 1-2 parts silane coupling agent, and flake aluminum nitride; wherein the weight ratio of flake aluminum nitride to flake boron nitride is 1:(1-2). The nano-magnesium oxide was prepared through modification, specifically as follows: S1. Add stearic acid to a 75% ethanol solution, stir and heat to 60-80℃ to prepare a 10-20% stearic acid solution. S2. Dry the nano-magnesium oxide at 100-120℃ for 2-4 hours, add it to the stearic acid solution, stir at 600-800 rpm, ultrasonically disperse for 15-30 minutes with an ultrasonic power of 300-500W, heat to 80-100℃, stir and react at a constant temperature for 2-4 hours, cool, filter and wash, and vacuum dry to obtain modified nano-magnesium oxide.
2. The overhead parallel bundled conductor according to claim 1, characterized in that, The insulating layer comprises the following raw materials in parts by weight: 85-95 parts cross-linked polyethylene, 0.7-0.9 parts antioxidant, 0.7-0.9 parts ultraviolet absorber, 3.5-4.5 parts nano magnesium oxide, 8-12 parts methyl vinyl silicone rubber, 5-7 parts flake boron nitride, and 1.3-1.8 parts silane coupling agent.
3. The overhead parallel bundled conductor according to claim 1, characterized in that, The weight ratio of the nano-magnesium oxide to methyl vinyl silicone rubber is 1:(2-4).
4. The overhead parallel bundled conductor according to claim 1, characterized in that, The weight ratio of the nano-magnesium oxide to the sheet-like boron nitride is 1:(1.3-1.7).
5. The overhead parallel bundled conductor according to claim 1, characterized in that: The mass ratio of the nano-magnesium oxide to stearic acid is 1:(0.5-1.5).