Direct current cable
By using a combination of inner core and outer conductor structure, the problem of uneven current distribution in traditional DC cables is solved, achieving current optimization and impedance reduction, and extending the service life of the cable.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-04
- Publication Date
- 2026-03-20
AI Technical Summary
Traditional DC cables often have a single stranded core, which can lead to oxidation, contamination, or uneven pressure at the contact points, resulting in localized current concentration, significant temperature rise, and shortened cable life.
It adopts a combination structure of inner core and outer conductor. The inner core carries the steady-state current, while the outer conductor shunts the high-frequency components, reducing the overall impedance. The current distribution is optimized through left-hand spiral twisting design and modified materials.
To achieve uniform current distribution, reduce impedance, avoid local overheating, extend cable life, and improve cable stability.
Smart Images
Figure CN224020510U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of cable, especially a direct current cable. BACKGROUND
[0002] The direct current cable is a power cable used in a direct current power transmission and distribution system.
[0003] The traditional direct current cable has a single twisted structure, i.e., a plurality of wires are twisted together in the same direction and pitch, such as a plurality of copper wires twisted together as the cable core. The twisted conductor is formed by a plurality of thin wires spirally wound together, and the contact points between the wires can have problems such as oxidation, contamination, or uneven pressure, resulting in differences in contact resistance. The path with lower resistance will pass more current, forming a local current concentration. The temperature in the area of local current concentration rises significantly, which can accelerate the aging of the insulation and even cause breakdown. Long-term uneven current distribution can cause material fatigue and shorten the service life of the cable.
[0004] Therefore, in view of the above situation, how to improve the existing cable to solve the above-mentioned shortcomings has become an important technical problem to be solved by the technical personnel in the field. CONTENT OF THE UTILITY MODEL
[0005] The utility model discloses a direct current cable, by the cable core 1 that inner core 11, and the outer conductor 12 set up on the inner core 11 in the mode of left spiral twisting are formed, can realize current optimization, wherein the inner core 11 bears steady-state current, the outer conductor 12 shunts high-frequency component, reduces overall impedance, can avoid the problem brought by single twisted structure, can solve the problem existing in the prior art.
[0006] The direct current cable provided by the utility model comprises a cable core 1, a heat-conducting insulation layer 2 and a composite shielding sheath layer 3 arranged in sequence from inside to outside.
[0007] The cable core 1 comprises an inner core 11 and an outer conductor 12 arranged on the inner core 11 in a left spiral twisting mode.
[0008] The heat-conducting insulation layer 2 covers the cable core 1 and is made of modified polyolefin material.
[0009] The composite shielding sheath layer 3 comprises a copper wire braided mesh inner layer 31 covering the heat-conducting insulation layer 2 and a flame-retardant polyvinyl chloride outer layer 32 covering the copper wire braided mesh inner layer 31.
[0010] Preferably,
[0011] The inner core 11 is made of tinned copper wire and coated with a graphene composite coating on the surface.
[0012] Preferably,
[0013] The thickness of the graphene composite coating is 0.1-0.35 mm.
[0014] Preferably,
[0015] The outer conductor 12 is several aluminum-clad copper wires spirally twisted on the inner core 11 in a left direction.
[0016] Preferably,
[0017] The outer conductor 12 comprises six aluminum-clad copper wires, and the twisting pitch of the aluminum-clad copper wires spirally twisted in a left direction is 25-35 mm.
[0018] The diameter of the aluminum-clad copper wire is 1.2-1.6 mm, and the diameter of the inner core 11 is 1.8-4 mm.
[0019] Preferably,
[0020] The heat-conducting insulation layer 2 is doped with boron nitride microsheets.
[0021] Preferably,
[0022] The outer surface of the heat-conducting insulation layer 2 is uniformly provided with raised stripes, and the height of the raised stripes is 0.2-0.3 mm.
[0023] Preferably,
[0024] The inner layer 31 of the copper wire braid is made of tinned copper wire braid, and the area covering the outer surface of the heat-conducting insulation layer 2 is not less than 90%.
[0025] Preferably,
[0026] The thickness of the flame-retardant polyvinyl chloride outer layer 32 is 0.8-1.2 mm.
[0027] The direct current cable of the utility model, comprising cable core 1, heat-conducting insulation layer 2 and composite shielding sheath layer 3 arranged from inside to outside in sequence, cable core 1 comprises inner core 11 and outer conductor 12 arranged on inner core 11 in a left direction spiral twisting mode, heat-conducting insulation layer 2 covers cable core 1 and is made of modified polyolefin material, composite shielding sheath layer 3 comprises inner layer 31 of copper wire braid covered on heat-conducting insulation layer 2 and outer layer 32 of flame-retardant polyvinyl chloride covering inner layer 31 of copper wire braid. Through cable core 1 composed of inner core 11 and outer conductor 12 arranged on inner core 11 in a left direction spiral twisting mode, the direct current cable of the utility model can realize current optimization, wherein inner core 11 bears steady-state current, outer conductor 12 shunts high-frequency components, reduces overall impedance and can avoid problems caused by single twisting structure, and the problems existing in the prior art can be solved. BRIEF DESCRIPTION OF DRAWINGS
[0028] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the drawings needed to be used in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.
[0029] Figure 1 It is a structural schematic view of the DC cable embodiment of the present application. DETAILED DESCRIPTION
[0030] The present application discloses a kind of DC cable, cable core 1 is formed by inner core 11, and outer conductor 12 arranged on inner core 11 in left spiral twisting mode, current optimization can be realized, wherein inner core 11 bears steady-state current, outer conductor 12 shunts high-frequency component, reduces overall impedance, can avoid the problem brought by single twisted structure, can solve the problems existing in prior art.
[0031] The technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. Please refer to Figure 1 The DC cable provided by the embodiments of the present application comprises cable core 1, heat-conducting insulation layer 2 and composite shielding sheath layer 3 arranged in sequence from inside to outside;
[0032] Cable core 1 comprises inner core 11 and outer conductor 12 arranged on inner core 11 in left spiral twisting mode;
[0033] Heat-conducting insulation layer 2 covers cable core 1 and is made of modified polyolefin material;
[0034] Composite shielding sheath layer 3 comprises copper wire braided mesh inner layer 31 covered outside heat-conducting insulation layer 2 and flame-retardant polyvinyl chloride outer layer 32 covering copper wire braided mesh inner layer 31.
[0035] In the present application, when DC cable works, if in ideal DC, current is uniformly distributed in conductor cross section; but in actual application, high-frequency component (such as ripple of switching power supply, electromagnetic interference, etc.) may exist in DC system, these high-frequency currents will cause large heat, and will choose different paths due to conductor impedance characteristics. The cable core 1 combined by inner core 11 and outer conductor 12 in the present application, wherein outer conductor 12 is designed to form distributed inductance in spiral, high-frequency current will choose different paths due to inductive reactance (X LThe increase of the inductance (2πfL) forces to select a path with lower inductance, i.e. the surface of the outer conductor 12, that is, the inner core 11 and the outer conductor 12 achieve a current shunt, and the inner core 11 delivers stable current, and the outer conductor 12 shunts high-frequency components.
[0036] Preferably,
[0037] The inner core 11 is made of tinned copper wire, and the surface is coated with a graphene composite coating.
[0038] It should be pointed out that the tinned copper wire is selected, and the graphene composite coating is coated, on the one hand, the high thermal conductivity of graphene is used to directly conduct heat to the heat-conducting insulation layer 2, and on the other hand, the contact resistance is reduced.
[0039] Preferably,
[0040] The thickness of the graphene composite coating is 0.1-0.35mm.
[0041] Preferably,
[0042] The outer conductor 12 is a plurality of aluminum-clad copper wires spirally twisted on the inner core 11.
[0043] Preferably,
[0044] The outer conductor 12 includes 6 said aluminum-clad copper wires, and the twisting pitch of the left-handed spiral twisting of the aluminum-clad copper wires is 25-35mm.
[0045] The diameter of the aluminum-clad copper wire is 1.2-1.6mm, and the diameter of the inner core 11 is 1.8-4mm.
[0046] Preferably,
[0047] The heat-conducting insulation layer 2 is doped with boron nitride micro-pieces.
[0048] Preferably,
[0049] The outer surface of the heat-conducting insulation layer 2 is uniformly provided with raised stripes, and the height of the raised stripes is 0.2-0.3mm.
[0050] It should be pointed out that the heat-conducting insulation layer 2 can quickly conduct heat, and the surface raised stripes enhance air convection heat dissipation, which is conducive to quickly conducting the heat of the cable core 1.
[0051] Preferably,
[0052] The copper wire braid inner layer 31 is made of tinned copper wire braid, and the area covering the outer surface of the heat-conducting insulation layer 2 is not less than 90%.
[0053] Preferably,
[0054] The thickness of the flame-retardant polyvinyl chloride outer layer 32 is 0.8-1.2 mm.
[0055] The direct current cable of the utility model, comprising cable core 1, heat conducting insulation layer 2 and composite shielding sheath layer 3 arranged in sequence from inside to outside, cable core 1 comprises inner core 11 and outer conductor 12 arranged on inner core 11 in left spiral lashing mode, heat conducting insulation layer 2 covers cable core 1 and is made of modified polyolefin material, composite shielding sheath layer 3 comprises copper wire braided mesh inner layer 31 covered outside heat conducting insulation layer 2 and flame-retardant polyvinyl chloride outer layer 32 covering copper wire braided mesh inner layer 31. The direct current cable of the utility model, comprising cable core 1, heat conducting insulation layer 2 and composite shielding sheath layer 3 arranged in sequence from inside to outside, cable core 1 comprises inner core 11 and outer conductor 12 arranged on inner core 11 in left spiral lashing mode, heat conducting insulation layer 2 covers cable core 1 and is made of modified polyolefin material, composite shielding sheath layer 3 comprises copper wire braided mesh inner layer 31 covered outside heat conducting insulation layer 2 and flame-retardant polyvinyl chloride outer layer 32 covering copper wire braided mesh inner layer 31. Through cable core 1 composed of inner core 11 and outer conductor 12 arranged on inner core 11 in left spiral lashing mode, the utility model can realize current optimization, wherein inner core 11 bears steady current and outer conductor 12 shunts high frequency component, reduces overall impedance and can avoid problems caused by single lashing structure and solve problems existing in prior art.
[0056] The direct current cable of the utility model, comprising cable core 1, heat conducting insulation layer 2 and composite shielding sheath layer 3 arranged in sequence from inside to outside, cable core 1 comprises inner core 11 and outer conductor 12 arranged on inner core 11 in left spiral lashing mode, heat conducting insulation layer 2 covers cable core 1 and is made of modified polyolefin material, composite shielding sheath layer 3 comprises copper wire braided mesh inner layer 31 covered outside heat conducting insulation layer 2 and flame-retardant polyvinyl chloride outer layer 32 covering copper wire braided mesh inner layer 31. The direct current cable of the utility model, comprising cable core 1, heat conducting insulation layer 2 and composite shielding sheath layer 3 arranged in sequence from inside to outside, cable core 1 comprises inner core 11 and outer conductor 12 arranged on inner core 11 in left spiral lashing mode, heat conducting insulation layer 2 covers cable core 1 and is made of modified polyolefin material, composite shielding sheath layer 3 comprises copper wire braided mesh inner layer 31 covered outside heat conducting insulation layer 2 and flame-retardant polyvinyl chloride outer layer 32 covering copper wire braided mesh inner layer 31. Through cable core 1 composed of inner core 11 and outer conductor 12 arranged on inner core 11 in left spiral lashing mode, the utility model can realize current optimization, wherein inner core 11 bears steady current and outer conductor 12 shunts high frequency component, reduces overall impedance and can avoid problems caused by single lashing structure and solve problems existing in prior art.
Claims
1. A DC cable, characterized in that, It includes a cable core (1), a thermally conductive insulation layer (2), and a composite shielding sheath layer (3), arranged sequentially from the inside out; The cable core (1) includes an inner core (11) and an outer conductor (12) arranged on the inner core (11) in a left-hand spiral twisted manner; The thermally conductive insulation layer (2) covers the cable core (1) and is made of modified polyolefin material; The composite shielding sheath layer (3) includes a copper wire braided mesh inner layer (31) covering the thermally conductive insulating layer (2) and a flame-retardant polyvinyl chloride outer layer (32) covering the copper wire braided mesh inner layer (31).
2. The DC cable according to claim 1, characterized in that, The inner core (11) is made of tin-plated copper wire and coated with a graphene composite coating.
3. The DC cable according to claim 2, characterized in that, The thickness of the graphene composite coating is 0.1 to 0.35 mm.
4. The DC cable according to claim 1, characterized in that, The outer conductor (12) consists of several aluminum-clad copper wires twisted in a left-hand spiral on the inner core (11).
5. The DC cable according to claim 4, characterized in that, The outer conductor (12) includes 6 aluminum-clad copper wires, and the aluminum-clad copper wires are twisted in a left-hand spiral with a twist pitch of 25-35 mm. The diameter of the aluminum-clad copper wire is 1.2 to 1.6 mm, and the diameter of the inner core (11) is 1.8 to 4 mm.
6. The DC cable according to any one of claims 1 to 5, characterized in that, Boron nitride microplates are doped into the thermally conductive insulating layer (2).
7. The DC cable according to claim 6, characterized in that, Raised stripes are uniformly arranged on the outer surface of the thermally conductive insulating layer (2), and the height of the raised stripes is 0.2 to 0.3 mm.
8. The DC cable according to any one of claims 1 to 5, characterized in that, The inner layer (31) of the copper wire braided mesh is made of tin-plated copper wire braided mesh, and the area covering the outer periphery of the thermally conductive insulating layer (2) is not less than 90%.
9. The DC cable according to claim 8, characterized in that, The thickness of the flame-retardant polyvinyl chloride outer layer (32) is 0.8 to 1.2 mm.