New energy vehicle high-voltage integrated liquid cooling transmission cable

Abstract

This invention discloses a high-voltage integrated liquid-cooled transmission cable for new energy vehicles, belonging to the field of wires and cables. It includes a composite conductor core, an outer layer of high-temperature resistant modified XLPE insulation, multiple liquid-cooled microchannels symmetrically arranged outside the insulation layer, an inner shielding layer at the outer end of each microchannel, a buffer damping layer outside the inner shielding layer, an outer shielding layer outside the buffer damping layer, and an outer sheath outside the outer shielding layer. The composite conductor core uses a mixture of multi-strand ultra-fine tin-plated copper strands and high-strength aluminum-magnesium alloy wire. While ensuring a conductivity ≥95% IACS, the weight is reduced by 25%~30% compared to pure copper conductors, and flexibility is significantly improved. It can achieve stable transmission of 800V high voltage and 500A high current, efficient liquid cooling, strong electromagnetic shielding, high flexibility and lightweight, wide temperature range weather resistance, and ultra-long service life, comprehensively solving the problems of excessive temperature rise, severe interference, insufficient flexibility, short lifespan, and poor safety of traditional cables.

Description

Technical Field

[0001] This invention relates to the field of wires and cables, and more specifically, to a high-voltage integrated liquid-cooled transmission cable for new energy vehicles. Background Technology

[0002] As a core carrier of global transportation energy transformation, new energy vehicles are rapidly iterating and upgrading towards higher voltage, higher current, higher power, and longer range. Currently, mainstream new energy vehicles have fully entered the 800V high-voltage platform era, with peak charging currents exceeding 500A. High-voltage transmission cables, as the "cardiovascular system" connecting the power battery, drive motor, on-board charger, and PDU high-voltage power distribution unit, directly determine the vehicle's safety, range, and service life through their electrical performance, heat dissipation capacity, electromagnetic compatibility, mechanical reliability, and environmental adaptability. High-voltage transmission cables operate under complex on-board conditions of strong vibration, wide temperature range, high oil contamination, and high electromagnetic radiation, while simultaneously meeting stringent domestic and international standards such as GB / T18487, GB / T20234, ISO6722, and LV216, placing extremely high demands on material and structural design.

[0003] First, high-current transmission results in excessive temperature rise and severely inadequate heat dissipation. Traditional cables rely on natural convection for heat dissipation. When operating continuously at 500A high current, Joule heat accumulates rapidly in the conductor, and the cable surface temperature can easily exceed 120°C, even approaching the long-term service limit of the insulation material. High temperatures accelerate the aging, embrittlement, and cracking of the insulation layer, leading to a decrease in insulation resistance and an increase in partial discharge. Long-term use can easily result in safety accidents such as insulation breakdown, short circuits, and fires. At the same time, heat accumulation can also lead to a decrease in conductor yield strength and structural creep, causing wire breakage and strand unraveling under vibration conditions, directly affecting transmission stability and overall vehicle safety.

[0004] Secondly, severe electromagnetic interference fails to meet the EMC requirements of high-precision automotive electronic equipment. High-voltage cables generate strong electromagnetic radiation and conducted interference during current switching, PWM modulation, and fast charging start-up and shutdown. Traditional single-layer braided shielding has low density and its shielding effectiveness is typically only 40–60 dB, making it difficult to suppress broadband interference. This type of interference directly affects the normal operation of precision electronic equipment such as automotive millimeter-wave radar, cameras, domain controllers, GPS navigation, and vehicle networking modules, leading to signal distortion, positioning drift, and functional abnormalities. In severe cases, it can cause the failure of autonomous driving assistance systems, posing a significant safety hazard.

[0005] In summary, existing high-voltage transmission cables for new energy vehicles are no longer able to meet the development requirements of 800V high-voltage platforms, super-fast charging, high safety, long lifespan, and lightweight design. They suffer from a series of technical pain points, including excessive temperature rise, EMC non-compliance, poor flexibility, short lifespan, low safety, and insufficient integration. Therefore, developing a new type of high-voltage transmission cable with efficient liquid cooling, high shielding effectiveness, lightweight and high flexibility, high flame retardancy and weather resistance, and integrated design has become a core technical problem urgently needing to be solved by the new energy vehicle industry. Summary of the Invention

[0006] To address the problems existing in the prior art, the purpose of this invention is to provide a high-voltage integrated liquid-cooled transmission cable for new energy vehicles. It can achieve stable transmission of 800V high voltage and 500A high current, efficient liquid cooling heat dissipation, strong electromagnetic shielding, high flexibility and lightweight, wide temperature range weather resistance and ultra-long service life, and comprehensively solve the problems of excessive temperature rise, serious interference, insufficient flexibility, short life and poor safety of traditional cables.

[0007] To address the aforementioned problems, this invention employs the following technical solution: a high-voltage integrated liquid-cooled transmission cable for new energy vehicles, comprising a composite conductor core, an insulating layer on the outside of the composite conductor core, multiple liquid-cooled microchannels symmetrically arranged on the outside of the insulating layer, an inner shielding layer sleeved at the outer end of the multiple liquid-cooled microchannels, a buffer damping layer on the outside of the inner shielding layer, an outer shielding layer on the outside of the buffer damping layer, and an outer sheath on the outside of the outer shielding layer. This enables stable transmission of 800V high voltage and 500A high current, efficient liquid cooling, strong electromagnetic shielding, high flexibility and lightweight design, wide temperature range weather resistance, and ultra-long service life, comprehensively solving the problems of excessive temperature rise, severe interference, insufficient flexibility, short lifespan, and poor safety of traditional cables.

[0008] Furthermore, the composite conductor core is made of multi-strand ultra-fine tin-plated copper stranded wire mixed with high-strength aluminum-magnesium alloy wire. Under the premise of ensuring conductivity ≥95% IACS, the weight is reduced by 25%~30% compared with pure copper conductor, the flexibility is significantly improved, the stranding pitch ratio is 10~14, the conductor DC resistance is ≤0.050Ω / km, which meets the requirements of 800V / 500A high current transmission.

[0009] Furthermore, the insulation layer is made of high-temperature modified XLPE material with a temperature resistance rating of 150℃ and a dielectric strength of ≥50kV / mm, meeting the withstand voltage requirements of an 800V system.

[0010] Furthermore, the liquid-cooled microchannel is a flat, elliptical, thin-walled silicone tube. The liquid-cooled microchannel is evenly distributed along the cable axis and is closely attached to the composite conductor core to form an independent circulating cooling circuit. The inlet and outlet of the liquid-cooled microchannel are respectively located at both ends of the cable. With the help of a high thermal conductivity filling layer, heat can be quickly discharged and the steady-state temperature rise can be controlled within 60°C.

[0011] Furthermore, the inner shielding layer is a double-layer structure consisting of tin-plated copper wire braid and aluminum-plastic composite tape wrapping, with a braiding density ≥90%, a wrapping overlap rate ≥25%, and a shielding effectiveness ≥90dB.

[0012] Furthermore, the buffer damping layer is made of closed-cell foamed silicone rubber material with a thickness of 0.8~1.2mm. The closed-cell foamed silicone rubber material can absorb vibration and thermal expansion stress, prevent the insulation layer from bulging and breaking, and has both buffering and vibration reduction and heat insulation functions, suppressing the thermal expansion of the conductor from breaking through the insulation layer.

[0013] Furthermore, the outer shielding layer is made of graphene-doped conductive nylon tape, and the dual shielding of the inner and outer shielding layers suppresses electromagnetic radiation and conduction interference.

[0014] Furthermore, the outer sheath is made of ceramicized silicone rubber material, which turns into ceramic when exposed to fire and has flame-retardant, oil-resistant, electrolyte-resistant, and aging-resistant properties, making it suitable for harsh vehicle environments.

[0015] Furthermore, the space between the insulating layer and the inner shielding layer is filled with highly thermally conductive ceramic powder with a thermal conductivity ≥1.2W / (m•K), thereby constructing a continuous thermal conduction path and improving the overall heat dissipation efficiency.

[0016] Furthermore, the overall bending radius of the cable is ≤5 times the outer diameter of the cable, the cable structure is compact, the bending radius is small, and it is suitable for complex wiring scenarios such as chassis, cabin, and charging ports.

[0017] Compared with the prior art, the advantages of this invention are:

[0018] 1. This solution adopts a three-in-one structure of copper-aluminum stranded composite conductor + integrated liquid-cooled microchannel + high thermal conductivity filling layer. While ensuring stable transmission of 800V / 500A high current, it achieves rapid heat dissipation and efficient heat dissipation, keeping the steady-state temperature rise below 60℃, significantly reducing the insulation aging rate, avoiding the risk of thermal runaway, and greatly improving the safety and service life of high voltage transmission.

[0019] 2. This solution adopts a double-layer composite shielding structure consisting of tin-plated copper wire braiding + aluminum-plastic composite tape inner shielding and graphene-doped conductive nylon tape outer shielding. The shielding effectiveness is ≥90dB, which can block high-voltage electromagnetic radiation and conducted interference in all directions, ensuring the stable operation of precision equipment such as vehicle radar and domain controllers, and meeting the stringent EMC design requirements of the whole vehicle.

[0020] 3. This solution achieves lightweight cable design, small bending radius (≤5 times outer diameter), high vibration fatigue resistance and strong environmental adaptability through a closed-cell foamed silicone rubber buffer damping layer + highly flexible layered structure + ceramicized silicone rubber flame-retardant sheath. It also features oil resistance, electrolyte resistance, VW-1 flame retardancy, and low smoke and halogen-free characteristics, making it fully adaptable to complex vehicle operating conditions and matching the service life with the vehicle's life. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the entire invention;

[0022] Figure 2 This is a perspective view of the liquid-cooled microchannel portion of the present invention.

[0023] Explanation of the labels in the diagram:

[0024] 1. Composite conductor core; 2. Insulation layer; 3. Liquid-cooled microchannel; 4. Inner shielding layer; 5. Buffer damping layer; 6. Outer shielding layer; 7. Outer sheath. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] Example

[0029] Please see Figure 1-2 A high-voltage integrated liquid-cooled transmission cable for new energy vehicles includes a composite conductor core 1, an outer high-temperature resistant modified XLPE insulation layer 2, multiple liquid-cooled microchannels 3 symmetrically arranged outside the insulation layer 2, an inner shielding layer 4 sleeved at the outer end of the multiple liquid-cooled microchannels 3, a buffer damping layer 5 outside the inner shielding layer 4, an outer shielding layer 6 outside the buffer damping layer 5, and an outer sheath 7 outside the outer shielding layer 6. This cable enables stable transmission of 800V high voltage and 500A high current, efficient liquid cooling, strong electromagnetic shielding, high flexibility and lightweight design, wide temperature range weather resistance, and ultra-long service life, comprehensively solving the problems of excessive temperature rise, severe interference, insufficient flexibility, short lifespan, and poor safety of traditional cables.

[0030] Please see Figure 1-2 The composite conductor core 1 uses a multi-strand ultra-fine tinned copper stranded wire mixed with aluminum-magnesium alloy wire, with a stranding pitch ratio of 10~14. The conductor DC resistance is ≤0.050Ω / km, meeting the requirements for 800V / 500A high-current transmission. The liquid-cooled microchannel 3 is a flat, elliptical, thin-walled silicone tube, evenly distributed along the cable axis, tightly fitted with the composite conductor core to form an independent circulating cooling circuit. The inlet and outlet are located at both ends of the cable, respectively. The inner shielding layer 4 is a double-layer structure of tinned copper wire braiding and aluminum-plastic composite tape wrapping, with a braiding density ≥90%, a wrapping overlap rate ≥25%, and a shielding effectiveness ≥90dB. The buffer damping layer 5 is made of closed-cell foamed silicone rubber with a thickness of 0.8~1.2m. The cable features both buffering and vibration damping as well as heat insulation, preventing the conductor's thermal expansion from breaking through the insulation layer. The outer shielding layer 6 is made of graphene-doped conductive nylon tape, maintaining stable conductivity and shielding performance within a wide temperature range of -40℃ to 180℃. The outer sheath 7 is made of ceramicized silicone rubber, which forms a hard ceramic layer when exposed to fire, achieving a flame retardant rating of VW-1. It is also oil-resistant, electrolyte-resistant, and aging-resistant. The space between the insulation layer 2 and the inner shielding layer 4 is filled with high thermal conductivity ceramic powder, with a thermal conductivity ≥1.2W / (m•K), accelerating heat transfer to the liquid cooling microchannel. The overall bending radius of the cable is ≤5 times the cable's outer diameter, resulting in a compact cable structure and a small bending radius, making it suitable for complex wiring scenarios such as chassis, cabins, and charging ports.

[0031] Principle: High current is transmitted through the composite conductor core 1, and the heat generated is quickly transferred to the liquid-cooled microchannel 3 through the insulation layer 2 and the thermally conductive ceramic powder. The circulating coolant continuously removes the heat, controlling the temperature rise of the cable. The double-layer shielding layer blocks high-voltage electromagnetic interference. The buffer damping layer 5 absorbs vibration and thermal expansion stress, protecting the insulation layer 2. The ceramicized silicone rubber outer sheath 7 provides flame retardant, oil-resistant, and aging-resistant protection, ensuring the cable can work stably for a long time in harsh vehicle environments.

[0032] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.

Claims

1. A high-voltage integrated liquid-cooled transmission cable for new energy vehicles, comprising a composite conductor core (1), characterized in that: The composite conductor core (1) is provided with an insulating layer (2) on the outside. Multiple liquid-cooled microchannels (3) are symmetrically arranged on the outside of the insulating layer (2). An inner shielding layer (4) is provided on the outer end of the multiple liquid-cooled microchannels (3). A buffer damping layer (5) is provided on the outside of the inner shielding layer (4). An outer shielding layer (6) is provided on the outside of the buffer damping layer (5). An outer sheath (7) is provided on the outside of the outer shielding layer (6).

2. The high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The composite conductor core (1) adopts a multi-strand ultra-fine tin-plated copper stranded wire and aluminum-magnesium alloy wire mixed stranded structure, with a stranding diameter ratio of 10~14 and a conductor DC resistance ≤0.050Ω / km.

3. The high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The insulating layer (2) is made of high-temperature resistant modified XLPE material.

4. The high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The liquid-cooled microchannel (3) is a flat elliptical thin-walled silicone tube. The liquid-cooled microchannel (3) is evenly distributed along the cable axis and closely attached to the composite conductor core to form an independent circulating cooling circuit. The inlet and outlet of the liquid-cooled microchannel (3) are respectively located at both ends of the cable.

5. The high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The inner shielding layer (4) is a double-layer structure of tin-plated copper wire braid and aluminum-plastic composite tape wrapping, with a braiding density of ≥90%, a wrapping overlap rate of ≥25%, and a shielding effectiveness of ≥90dB.

6. The high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The buffer damping layer (5) is made of closed-cell foamed silicone rubber with a thickness of 0.8~1.2mm.

7. The high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The outer shielding layer (6) is made of graphene-doped conductive nylon tape.

8. The high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The outer sheath (7) is made of ceramicized silicone rubber material.

9. The high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The insulating layer (2) and the inner shielding layer (4) are filled with high thermal conductivity ceramic powder, and its thermal conductivity is ≥1.2W / (m•K).

10. A high-voltage integrated liquid-cooled transmission cable for new energy vehicles according to claim 1, characterized in that: The overall bending radius of the cable is ≤5 times the outer diameter of the cable.

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