Compressed aluminum conductor corrugated shielding bus for high-power-density electric automobile and manufacturing method of compressed aluminum conductor corrugated shielding bus

Abstract

The invention discloses a compressed aluminum conductor corrugated shielding bus for a high-power-density electric automobile and a manufacturing method, and provides a multi-layer composite structure aiming at the problems that an existing aluminum conductor is poor in mechanical performance, remarkable in high-frequency skin effect, low in electromagnetic shielding effectiveness, insufficient in heat dissipation and the like. The tensile strength reaches 180-220 MPa, and the high frequency Rac / Rdc is smaller than or equal to 1.15 at 10 kHz; the corrugated shielding layer is composed of a corrugated aluminum pipe, the shielding effectiveness is larger than or equal to 82dB and 1MHz, and the heat dissipation efficiency is improved by larger than or equal to 35% by combining the pre-embedded micro-channel and dielectric fluid circulation; the sheath layer is integrated with a wave-absorbing material and additionally provides 10-15dB electromagnetic shielding attenuation. According to the preparation method, integrated manufacturing is achieved through three-stage calendering, double-layer co-extrusion and hydraulic forming processes, the weight of the bus is reduced by 60% compared with that of copper, the power density reaches 8.7 kW / kg, the bending radius is reduced to 5D, the whole life cycle cost is reduced by 42%, and the requirements for light weight and high reliability of 800V and above high-voltage fast charging platforms are met.

Description

Technical Field

[0001] This invention relates to the technical field of power transmission equipment, and more specifically, to a compressed aluminum conductor corrugated shielded busbar for high power density electric vehicles and its manufacturing method. Background Technology

[0002] As high-voltage fast charging technology for electric vehicles develops towards 800V and above platforms, charging systems face more stringent requirements regarding the power density, lightweight design, and reliability of the busbars. However, existing technologies suffer from systemic defects in many aspects, severely hindering the promotion and application of high-voltage fast charging technology.

[0003] 1. Limitations of Conductor Materials Traditional busbars mostly use copper conductors to meet conductivity requirements (IACS≥98%), but their high cost (3.2 times that of aluminum for the same current carrying capacity) and density (8.96g / cm³) are problematic. 3 This limits lightweight design. When using aluminum conductors (IACS≈61%), the tensile strength of conventional 1350-O aluminum conductors is only 80–120 MPa (ASTM B230 test), and the bending life is ≤5 × 10⁻⁵. 4 Repeated bending can easily cause cracks; the thickness of the natural oxide layer is uneven (0.01~0.1μm), the contact resistance fluctuates by ±15% (UL 486E standard), and the skin effect deteriorates significantly under high-frequency operating conditions.

[0004] Furthermore, space charge (density up to 10) easily accumulates at the interface between aluminum conductors and insulation. 12 ~10 13 e / cm 3 The PWP method test caused electric field distortion, resulting in excessive partial discharge (>50pC under 1500V DC superimposed pulse condition, exceeding the limit of GB / T 3048.12-2007 by 300%).

[0005] 2. Insufficient adaptability of the shielding structure. Existing electromagnetic shielding designs (such as CN112185582A) mostly employ copper wire braided layers (coverage ≥85%), which have poor dynamic reliability, with a wire breakage rate ≥3‰ / 1000 km under vibration conditions (QC / T 1037-2016 road test data). At high frequencies (above 1MHz), the shielding effectiveness drops sharply to below 40dB (IEC 62153-4-7 test), and the solid metal shielding layer has a high thermal resistivity of 2.5℃·m / W, hindering heat dissipation. Recent improvements, such as US20210091427A1 proposing an aluminum-plated copper composite conductor, have a plating shear strength <15MPa, posing a risk of peeling. CN113451002B uses double-layer copper strip wrapping shielding, but this results in a 25% increase in outer diameter, failing to solve the problem of synergistic effect between lightweight design and high-efficiency shielding.

[0006] 3. Functional deficiencies in the sheath material Commercially available sheathing materials (such as PVC and ordinary TPU) perform poorly in extreme environments: PVC embrittlement impact strength < 4kJ / m at -40℃. 2 According to GB / T 1843-2008, the tensile strength of TPU decreases by more than 60% at 175℃; in acid rain environments (pH=3.5), the water absorption rate is greater than 1.2% (ASTM D570 test), which exacerbates electrochemical corrosion. In addition, existing sheaths lack compatibility designs with intelligent monitoring (such as distributed optical fibers) and active cooling systems, and have a high surface friction coefficient (μ=0.2~0.4), resulting in high wiring resistance.

[0007] 4. High-voltage system mismatch issues Current busbars fail to meet the core specifications of the 800V platform: a typical 400A busbar weighs >3kg / m (EN 62196-3 requires a holding force <50N), with a power density of only 5.2kW / kg; insulation compatibility is insufficient, with charge accumulation at the aluminum conductor / insulation interface causing electric field distortion; traditional single-layer XLPE insulation exceeds partial discharge limits under high-voltage superimposed pulse conditions. Furthermore, space constraints limit the bending radius to 8D (D being the conductor diameter), making it difficult to adapt to compact chassis designs.

[0008] Despite recent patent attempts to improve the system, such as using aluminum-plated copper composite conductors or double-layer copper strip shielding, none have systematically solved the problem of synergistic optimization of lightweight design, high shielding effectiveness, and strong protection. For example, the aluminum-plated copper solution suffers from reduced reliability due to insufficient interfacial bonding, while copper strip shielding sacrifices its lightweight advantage. Therefore, there is an urgent need for an innovative structure that, through material optimization, process innovation, and multi-level functional integration, breaks through existing technological bottlenecks to meet the high power density, low cost, and long lifespan requirements of high-voltage fast charging systems for electric vehicles. Summary of the Invention

[0009] The purpose of this invention is to solve the problems of poor mechanical properties of aluminum conductors, significant high-frequency skin effect, low electromagnetic shielding effectiveness, insufficient heat dissipation, and bulky busbars in existing technologies. It proposes a high-power-density compressed aluminum conductor corrugated shielded busbar and its manufacturing method for electric vehicles. It can improve tensile strength and high-frequency conductivity through high-compression aluminum conductors, optimize electromagnetic shielding and heat dissipation efficiency through corrugated shielding layer, reduce weight and installation difficulty through lightweight structure, and achieve low-cost high-power-density design by combining efficient molding process, so as to meet the requirements of lightweight, high reliability and high-frequency compatibility of 800V and above high-voltage fast charging platforms.

[0010] To achieve the above objectives, this invention proposes a high-power-density compressed aluminum conductor corrugated shielded busbar for electric vehicles, comprising the following sequentially composited layered structures: (1) Conductor layer: It is composed of micro-alloyed aluminum material with a compression ratio (specifically referring to the compression ratio in material processing) of 30% to 40%, and a dense oxide layer of 2 to 10 μm is formed on the surface. The aluminum material is cold-pressed and grain-refined, with a tensile strength of 180 to 220 MPa, an elongation at break of ≥15%, and a Rac / Rdc ratio of ≤1.15 under 10 kHz high-frequency conditions. The conductor layer adopts a tight-stranding process, which specifically involves twisting circular monofilaments with a diameter of 0.5 to 1.0 mm in the same direction. The conductor is wound in a unidirectional (all single filaments are twisted in the same direction) manner to form an initial stranded structure; a three-stage compaction die process is then performed, with the cross-sectional height of each stage of the calendering die decreasing by 1 mm compared to the previous stage, and a radial pressure of 50-80 MPa is applied, with the stranding direction being left-hand coaxial stranding, so that the porosity between the single filaments is reduced from 15%-20% to 8%-10%, ultimately forming a flat conductor with a width-to-thickness ratio (the ratio of the conductor's cross-sectional width to its thickness) of 2:1, and a compaction coefficient (the density of the conductor after stranding) ≥0.92; (2) Insulation layer: Covered outside the conductor layer, made of PA12 material with a temperature resistance of 125℃, with a thickness of 0.5~1.5mm, and bonded to the surface of the conductor layer through a double-layer co-extrusion process, with a peel strength ≥25N / cm; (3) Corrugated shielding layer: It is composed of corrugated aluminum tubes with a wall thickness of 0.15 to 0.25 mm, a corrugated pitch of 5 to 8 mm, a depth of 2.0 to 3.0 mm, a waveform angle of 50° to 70°, and the ratio of corrugated pitch to conductor layer pitch is 1:1.2, with a shielding effectiveness ≥82dB@1MHz; (4) Sheath layer: Covering the corrugated shielding layer, it is made by co-extrusion of TPEE matrix and flame-retardant PA12 outer layer, with a wall thickness of 2.0~3.0mm and a surface friction coefficient μ≤0.15 (tested according to DIN 53375 standard), and the heat dissipation area is increased by 20% through groove design.

[0011] Preferably, rare earth elements are added to the microalloyed aluminum material of the conductor layer through an aging annealing process, with a doping amount of 0.05 to 0.3 wt%, and the conductor cross-section width-to-thickness ratio is 2:1, with a current carrying capacity of ≥680A@90℃ temperature rise.

[0012] Preferably, the microchannels embedded in the bottom of the corrugated aluminum tube are connected to the dielectric fluid circulation system, with a cross-sectional size of 0.3mm × 0.5mm. The two ends of the microchannels are connected to the pipes of the dielectric fluid circulation system through embedded flow guides. The flow guides adopt a flared sealing structure, and the inner diameter of the interface matches the cross-sectional size of the microchannel. The flow guides are fixed to the corrugated aluminum tube by brazing. Under 500 A conditions, the heat dissipation efficiency is improved by ≥35% (ΔT is reduced by ≥18℃).

[0013] Preferably, carbon fiber reinforcement material is added to the TPEE matrix of the sheath layer, with an addition amount of 5-15 wt%, and the outer sheath integrates microwave absorbing material to provide an additional 10-15 dB of electromagnetic shielding attenuation.

[0014] The present invention also proposes a method for preparing a high power density electric vehicle compressed aluminum conductor corrugated shield busbar, comprising the following steps: (1) Conductor layer preparation: micro-alloyed aluminum material is subjected to three-stage rolling treatment, with a compression rate of 10-15% per stage (total compression rate of 30%-40%), and a rolling temperature of 150-200℃. The surface is subjected to micro-arc oxidation treatment to form nanoscale conductive channels; (2) Insulation layer forming: PA12 material is formed and coated onto the conductor layer in one step using a double-layer co-extrusion process, with a co-extrusion temperature of 220-200℃. 50℃, pressure is 8~12MPa; (3) Corrugated shielding layer processing: 3003 aluminum alloy strip is made into corrugated aluminum tube by hydraulic forming process, microchannels are pre-embedded at the bottom of the corrugation valley, and the flow guide joint is fixed by brazing process. The corrugation depth is 2.0~3.0mm, and self-locking interface is used for connection; (4) Sheath layer composite: TPEE matrix and flame retardant PA12 outer layer are co-extruded and wrapped in corrugated shielding layer. The co-extrusion temperature is 180~200℃ and 240~260℃ respectively. After cooling, a surface groove structure is formed.

[0015] Preferably, the grain size of the microalloyed aluminum material in step (1) is ≤5μm, and the interface resistance of the cold-pressed weld is ≤3.5μΩ·cm. 2 .

[0016] Preferably, the corrugated aluminum tube in step (3) is formed under a pressure of 50-80 MPa, and after forming, it undergoes aging annealing at a temperature of 180-220℃ for 1-2 hours. The negative Poisson's ratio characteristic of the corrugated unit ensures that the radial expansion deformation is ≥10% (tested according to ISO 6892-1 standard, the lateral expansion rate under radial pressure of 50 MPa). The negative Poisson's ratio characteristic is achieved through a trapezoidal sidewall with a waveform angle of 50°-70°. When the radial pressure F is applied, the sidewall inclination angle θ satisfies the expansion deformation ΔL = F × tanθ / (2E), where E is the elastic modulus of the material.

[0017] The beneficial effects of this invention are: 1. Significantly improved conductor performance: Through high compressibility (30%–40%) micro-alloyed aluminum and surface oxide layer (2–10 μm), tensile strength of 180–220 MPa, elongation at break ≥15%, Rac / Rdc ≤1.15@10kHz under high-frequency conditions, current carrying capacity of 680A@90℃, and stable contact resistance (≤3.5 μΩ·cm) are achieved. 2 This effectively inhibits the skin effect and space charge accumulation. 2. Breakthrough in electromagnetic compatibility and heat dissipation: The corrugated aluminum tube shielding layer (shielding effectiveness ≥82dB@1MHz) combined with the pre-embedded microchannel dielectric fluid circulation system improves heat dissipation efficiency by ≥35%, and the corrugated structure optimizes electromagnetic reflection and current distribution, while maintaining a shielding effectiveness of 75dB in the high-frequency band (10GHz). 3. Lightweight and reliable synergy: Through optimized width-to-thickness ratio (2:1), weight reduction of corrugated aluminum tube (≤85g / m per meter) and low friction sheath (μ≤0.15), the busbar weight is reduced by 60% compared to copper, the bending radius is reduced to 5D, the vibration resistance deformation capability is improved (resistance change rate <0.3%), and the dynamic working condition stability is excellent. 4. High-efficiency manufacturing and cost advantages: Three-stage calendering, double-layer co-extrusion and hydroforming processes enable integrated production of conductor-insulation-shielding-sheath, with a power density of 8.7kW / kg (industry average 5.2kW / kg), a 42% reduction in total life cycle cost, and compatibility with 800V and above high-voltage fast charging platforms, meeting the core requirements of lightweight, high reliability and long life (300,000 km).

[0018] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the manufacturing process of the high-power-density compressed aluminum conductor corrugated shielded busbar for electric vehicles according to the present invention. Detailed Implementation

[0020] See Figure 1 The busbar of the present invention comprises the following sequentially composited layered structures: (1) Conductor layer: It is composed of micro-alloyed aluminum material with a compression ratio of 30% to 40%, and a dense oxide layer of 2 to 10 μm is formed on the surface. The aluminum material is cold-pressed and grain-refined, with a tensile strength of 180 to 220 MPa, an elongation at break of ≥15%, and a Rac / Rdc ratio of ≤1.15 under 10 kHz high-frequency conditions. The conductor layer adopts a tight-stranding process, which specifically involves twisting circular monofilaments with a diameter of 0.5 to 1.0 mm in the same direction. (All single filaments are twisted in the same direction) and wound around the central conductor to form an initial twisted structure; a three-stage compaction die process is performed, with the cross-sectional height of each stage of the calendering die reduced by 1 mm compared to the previous stage, and a radial pressure of 50-80 MPa is applied, with the twisting direction being left-hand coaxial twisting, so that the porosity between single filaments is reduced from 15%-20% to 8%-10%, and finally a flat conductor with a width-to-thickness ratio (the ratio of the conductor's cross-sectional width to its thickness) of 2:1 is formed, with a compaction coefficient ≥0.92; (2) Insulation layer: Covered outside the conductor layer, made of PA12 material with a temperature resistance of 125℃, with a thickness of 0.5~1.5mm, and bonded to the surface of the conductor layer through a double-layer co-extrusion process, with a peel strength ≥25N / cm; (3) Corrugated shielding layer: It is composed of corrugated aluminum tubes with a wall thickness of 0.15 to 0.25 mm, a corrugated pitch of 5 to 8 mm, a depth of 2.0 to 3.0 mm, a waveform angle of 50° to 70°, and the ratio of corrugated pitch to conductor layer pitch is 1:1.2, with a shielding effectiveness ≥82dB@1MHz; (4) Sheath layer: Covering the corrugated shielding layer, it is made by co-extrusion of TPEE matrix and flame-retardant PA12 outer layer, with a wall thickness of 2.0~3.0mm and a surface friction coefficient μ≤0.15 (tested according to DIN 53375 standard), and the heat dissipation area is increased by 20% through groove design.

[0021] The method for preparing the busbar of the present invention includes the following steps: (1) Conductor layer preparation: micro-alloyed aluminum material is subjected to three-stage rolling treatment, with a compression rate of 10-15% per stage (total compression rate of 30%-40%), and the rolling temperature is 150-200℃. The surface is subjected to micro-arc oxidation treatment to form nanoscale conductive channels; (2) Insulation layer forming: PA12 material is formed and coated onto the conductor layer in one step using a double-layer co-extrusion process, with a co-extrusion temperature of 220-250℃ and a pressure of 8-12 MPa. a; (3) Corrugated shielding layer processing: 3003 aluminum alloy strip is made into corrugated aluminum tube by hydraulic forming process, microchannels are pre-embedded at the bottom of the corrugation valley, and the flow guide joint is fixed by brazing process. The corrugation depth is 2.0~3.0mm, and a self-locking interface is used for connection; (4) Sheath layer composite: TPEE matrix and flame-retardant PA12 outer layer are co-extruded and wrapped in corrugated shielding layer. The co-extrusion temperatures are 180~200℃ and 240~260℃, respectively. After cooling, a surface groove structure is formed.

[0022] The conductor layer employs an improved circular compact stranding process. Specifically, circular monofilaments (0.5–1.0 mm in diameter) are wound around the central conductor in a left-left-left unidirectional stranding manner to form an initial stranded structure. Subsequently, a three-stage rolling process is performed, with the die size for each stage decreasing by 1–2 mm compared to the previous stage. By applying radial pressure (50–80 MPa) at each stage, the porosity between the monofilaments is reduced from 15%–20% in the stranded state to 8%–10% in the rolled state, ultimately forming a flat conductor with a width-to-thickness ratio of 2:1. This process inherits the core principle of circular compact stranding—"eliminating voids through external force"—while simultaneously increasing the conductor compaction coefficient from 90% in traditional circular compact stranding to over 92% through multi-stage rolling and material micro-alloying (adding 0.05–0.3 wt% rare earth elements), balancing density and processing flexibility.

[0023] The "negative Poisson's ratio characteristic" of the corrugated aluminum tube is achieved through waveform geometry design: the sidewall of the corrugated unit adopts a trapezoidal or arc-shaped structure (waveform angle 50°~70°). When subjected to radial pressure, the inclined sidewall forces the corrugated unit to expand laterally.

[0024] Working process of this invention: The invention relates to a high-power-density electric vehicle compressed aluminum conductor corrugated shielded busbar and its manufacturing method, which will be described in conjunction with the accompanying drawings during operation.

[0025] Table 1. Comparison of Existing Stranding Process Parameters (Not of this invention) parameter Wire twisting Circular tight-fitting twist Monofilament shape Arched or Z-shaped, seamless after splicing A circular monofilament, twisted together, transforms into a hexagon. Compressive coefficient ≥0.92 ≥0.90 Process characteristics Pre-formed monofilament splicing, no additional mold compression required. Apply radial pressure to compress the gap between monofilaments through a die. conductor outer diameter Reduce by 15% to 20% Reduce by 10% to 15% Electrical conductivity Low skin effect (Rac / Rdc≤1.10@10kHz) High-frequency resistor optimization (Rac / Rdc≤1.15@10kHz) Applicable Scenarios High-density, high-frequency applications (such as 800V fast charging) Conventional high-voltage power transmission scenarios Table 2 Comparison of Innovations in Corrugated Aluminum Tube Shielding Layers Technical features Prior art (CN112185582A / US20210091427A1) Innovation of this invention Shielding structure Copper wire braiding or solid aluminum tape offers low shielding effectiveness (≤75dB@1MHz). Corrugated aluminum tube structure, shielding effectiveness ≥82dB@1MHz Heat dissipation design No active heat dissipation, relies on external cooling Pre-embedded microchannels (0.3mm × 0.5mm) improve heat dissipation efficiency by ≥35%. Mechanical properties Rigid structure, poor vibration resistance (resistivity change rate > 2%) It exhibits negative Poisson's ratio characteristics, compressive expansion deformation ≥10%, and excellent vibration resistance (resistivity change rate <0.3%). Lightweight Solid metal shielding layer (weight > 100g / m) Corrugated aluminum tube (weight ≤85g / m), weight reduction of 45%. Process cost It requires welding or wrapping, and the process is complex. Hydraulic forming and self-locking interfaces reduce installation time by 40%. Example 1: Technical solution: 1. Conductor layer Material: 6063-T6 aluminum alloy, rolled in three stages (12% compression rate per stage, 36% total compression rate), with the rolling temperature controlled at 180℃±5℃.

[0026] Surface treatment: Anodizing to form a 5μm dense oxide layer (SEM test, conforming to ISO 7599:2018 (anodized film thickness test)).

[0027] Performance metrics: Tensile strength: 205 MPa (ASTM E8 / E8M test) Elongation at break: 18% (tested according to GB / T 228.1-2021) High-frequency resistance ratio: Rac / Rdc = 1.10 @ 10kHz (IEEE 835-1994 model) Contact resistance: 3.2 μΩ·cm 2 (Four-probe test) 2. Insulation layer Material: PA12 (temperature resistance 125℃), with conductor layer coated by double-layer co-extrusion process (co-extrusion temperature 235℃, pressure 10MPa).

[0028] Peel strength: 28 N / cm (tested in GB / T 2791-1995).

[0029] 3. Corrugated shielding layer Material: 3003 aluminum alloy, corrugated pitch 8mm, depth 2.4mm, corrugated angle 60°, corrugated pitch to conductor pitch ratio 1:1.2 (conductor pitch 9.6mm).

[0030] Shielding effectiveness: 85dB@1MHz (IEC 62153-4-7 test).

[0031] Heat dissipation efficiency: The pre-embedded microchannel (0.3mm×0.5mm) combined with dielectric fluid circulation improves heat dissipation efficiency by 38% (ΔT decreases by 19℃@500A).

[0032] 4. Sheath layer Materials: TPEE matrix + 5wt% carbon fiber reinforced composite material, co-extruded flame retardant PA12 outer layer (UL94 V-0 certified).

[0033] Coefficient of friction: μ=0.12 (tested according to DIN 53375 standard).

[0034] Surface groove design: Increases heat dissipation area by 22%.

[0035] Stranding process: A unidirectional stranding method is adopted (all single filaments are stranded in the same direction, referring to IEC 60228). The initial stranded outer diameter is 12mm. It is progressively compressed through three stages of flat calendering dies (section heights of 11mm, 10mm, and 9mm respectively), resulting in a final conductor cross-section of 18mm × 9mm (width-to-thickness ratio 2:1) and a compression coefficient of 92.5%. The calendering dies are made of YG8 cemented carbide, with hard chrome plating on the working surface. The plating thickness is 5–8μm, and the surface roughness Ra≤0.4μm. The size of each stage of calendering die is reduced by 1mm compared to the previous stage. During calendering, the die temperature is controlled at 180℃±5℃ using a constant-temperature oil bath, and the calendering speed is 0.5m / s, ensuring that the porosity between single filaments decreases from 15%–20% in the stranded state to 8%–10% in the calendered state.

[0036] Test data: Current carrying capacity: 680A @ 90℃ temperature rise (EN 62196-3 standard).

[0037] Bending radius: 5D (D is the outer diameter, tested according to ISO 6722-2018).

[0038] Weight: 1.2kg / m (3.1kg / m for copper conductors of the same specification).

[0039] Dynamic vibration performance: The resistance change rate after XYZ triaxial vibration test (SAE J2380 standard) is 0.25%.

[0040] Example 2 Technical solution: 1. Conductor layer Materials: Microalloyed aluminum (with 0.2wt% rare earth elements added), compression ratio 35% (three-stage rolling, each stage compression ratio 11.7%).

[0041] Performance metrics: Tensile strength: 218MPa High-frequency resistance ratio: Rac / Rdc = 1.08 @ 10kHz 2. Corrugated shielding layer The corrugated pitch is 6mm and the depth is 2.0mm (pitch-to-depth ratio 3:1), with a waveform angle of 55°.

[0042] Shielding effectiveness: 88dB@1MHz.

[0043] 3. Sheath layer Materials: TPEE matrix + 10wt% carbon fiber, flame-retardant PA12 outer layer.

[0044] Coefficient of friction: μ=0.10 (tested according to DIN 53375 standard).

[0045] Test data: Heat dissipation efficiency: ΔT decreases by 22℃ @ 500A (heat dissipation efficiency increases by 42%).

[0046] Current carrying capacity: 700A @ 90℃ temperature rise.

[0047] Bending radius: 4.5D (optimized corrugation matching design).

[0048] Example 3 (Extreme Environment Validation) Technical solution: To verify environmental tolerance at -40°C, pH 3.5 acid rain, and 175°C, this embodiment reduces the compression ratio to 30% of the lower limit of the claims and adjusts the corrugated pitch to 5mm (normally 6-8mm) to enhance vibration resistance. This embodiment adjusts some parameters to the lower limit of the claims (30% compression ratio) to verify performance under extreme conditions, without affecting the scope of protection of the claims. Under normal operating conditions, the shielding effectiveness still meets the requirement of ≥82dB@1MHz.

[0049] Sheath material: PA12 outer layer (acid rain resistant formula), TPEE matrix + 15% carbon fiber (Note: PA12 outer layer is the equivalent material of the claim "flame retardant PA12 outer layer", which is not beyond the scope of protection).

[0050] Test data (lower limit of performance under extreme conditions): shielding effectiveness 80dB@1MHz (still meets the requirement of ≥82dB under normal conditions), current carrying capacity 650A@90℃ (due to the reduction in compression ratio, the conductive area is slightly reduced, which is a reasonable attenuation).

[0051] Test conditions: -40℃ low temperature impact strength: 6.5kJ / m 2 (GB / T 1843-2008).

[0052] Water absorption rate after immersion in acid rain at pH 3.5 for 24 hours: 0.8% (ASTM D570).

[0053] Tensile strength retention rate at 175℃: 92% (GB / T 1040.2-2006).

[0054] Test data: Weather resistance: 93% of tensile strength is retained after 3000h UV aging (ISO 4892-3).

[0055] Chemical protection: Resistant to swelling and cracking after immersion in engine oil (ISO 1817).

[0056] This embodiment aims to verify the functional reliability of the busbar in extreme environments. Some performance indicators (such as shielding effectiveness) may be lower than conventional requirements, but they meet the emergency standards for specific scenarios (such as acid rain and extremely cold regions).

[0057] Example 4 (Comparison with conventional copper conductors) Technical solution: Traditional copper conductor busbar (cross-sectional area 120mm²) 2 (Copper purity ≥ 99.9%).

[0058] Under the same test conditions: current carrying capacity 400A @ 90℃ temperature rise, shielding effectiveness 75dB @ 1MHz.

[0059] Comparison data: Weight: 3.1 kg / m (copper) vs 1.2 kg / m (Example 1).

[0060] Cost: 45% reduction in total lifecycle costs (materials + processing + maintenance).

[0061] Power density: 8.7kW / kg (this invention) vs 5.2kW / kg (conventional copper conductor).

[0062] Table 3. Performance Comparison of the Invention and Traditional Copper Conductor Busbars Performance indicators Busbar of this invention Traditional copper conductor busbar Increase / Decrease Amount Weight (kg / m) 1.2 3.1 Reduced by 61% Current carrying capacity (A@90℃) 680 400 Increase by 70% Shielding effectiveness (dB@1MHz) 82 75 Increase by 9% Power density (kW / kg) 8.7 5.2 Increased by 67% Total life cycle cost 42% reduction - - Table 4. Performance Comparison with Traditional Copper Conductors and Ordinary Aluminum Conductors Performance indicators Busbar of this invention Traditional copper conductor busbar Ordinary aluminum conductor busbar Current carrying capacity (A@90℃ temperature rise) 680 (Example 1) 400 575 Weight (kg / m) 1.2 3.1 1.5 (Solid aluminum, not processed by compression) Cost (total life cycle) 42% reduction - Reduced by 20% (but performance still not up to standard) Tensile strength (MPa) 180～220 200-250 (copper) 80～120 High-frequency resistance ratio (Rac / Rdc@10kHz) ≤1.15 1.05 (copper) 1.48 Shielding effectiveness (dB@1MHz) ≥82 75 (copper braided layer) No effective shielding Bending radius 5D 8D 8D Improved heat dissipation efficiency ≥35% No active cooling none Table 5 Summary of key parameters in Examples 1-4 Example Compression ratio Corrugated pitch / depth Sheath material Current carrying capacity (A@90℃) Shielding effectiveness (dB@1MHz) Example 1 36% 8mm / 2.4mm TPEE + 5% carbon fiber 680 85 Example 2 35% 6mm / 2.0mm TPEE + 10% carbon fiber 700 88 Example 3 30% 5mm / 2.0mm PA12 + 15% carbon fiber 650 80 Example 4 - - Traditional copper conductor 400 75 Table 6. Extreme Environment Test Results Test Project Test conditions Results of Example 3 Standard requirements Low temperature impact strength -40℃, GB / T 1843-2008 <![CDATA[6.5kJ / m 2 ]]> <![CDATA[≥4kJ / m 2 ]]> Acid rain water absorption rate pH=3.5, 24h, ASTM D570 0.8% ≤1.2% High-temperature tensile strength retention rate 175℃, 1000h, GB / T 1040.2 92% ≥85% The data for ordinary aluminum conductors are based on ASTM B230 standard test results (without compression processing). Example 3 is an extreme environment test; parameter adjustments were made to verify low-temperature, acid rain, and high-temperature resistance. Shielding effectiveness, current carrying capacity, and other data are measured values ​​under operating conditions and do not represent conventional performance. Through the systematic verification of Examples 1-4, this invention fully demonstrates the innovative advantages of the compressed aluminum conductor corrugated shielded busbar for high-power-density electric vehicles. 1. Breakthrough in overall performance By employing a high compressibility microalloyed aluminum conductor (tensile strength 180~220MPa), a corrugated aluminum tube shielding layer (shielding effectiveness ≥82dB@1MHz), and a composite sheath (friction coefficient μ≤0.15 (tested according to DIN 53375 standard)), the synergistic optimization of lightweight (60% weight reduction), high reliability (dynamic vibration resistance change rate <0.3%), and high frequency compatibility (Rac / Rdc≤1.15@10kHz) is achieved.

[0063] The power density is increased to 8.7kW / kg, which is 67% higher than that of traditional copper conductor busbars (5.2kW / kg), meeting the core requirements of 800V and above high-voltage fast charging platforms.

[0064] 2. Technological and cost advantages The three-stage calendering, double-layer co-extrusion, and hydroforming process enables integrated manufacturing of conductor-insulation-shielding-sheath, reducing the total life cycle cost by 42%. The 42% reduction in total life cycle cost is calculated based on a comprehensive assessment of material costs, processing energy consumption, and maintenance costs (see comparative data in Examples 1-4).

[0065] The corrugated aluminum tube's self-locking design simplifies the installation process (reducing labor time by 40%), and its modular structure supports partial replacement, further reducing maintenance costs.

[0066] 3. Enhanced environmental adaptability The sheath material has passed extreme temperature (-40℃~175℃), acid rain (pH=3.5) and UV aging (3000h) tests, with a tensile strength retention rate of >90%, excellent chemical protection performance, and is suitable for complex vehicle environments.

[0067] 4. Wide applicability verification The embodiments cover different parameter combinations (compression ratio 30% to 35%, corrugated pitch 5 to 8 mm), extreme working conditions and multi-scenario applications (charging piles, vehicle power distribution systems), demonstrating the universality and stability of the technical solution.

[0068] This invention solves the key contradiction between lightweight, high reliability and low cost in high-voltage fast charging systems for electric vehicles through systematic innovation in materials, structure and process, and has significant technological advancement and industrialization value.

[0069] The synergistic effect of the "compressed aluminum conductor + corrugated shield + composite sheath" system allows this invention to achieve a non-obvious performance breakthrough through a three-level structural innovation: Compressed aluminum conductors: High compression ratio (30%–40%) and microalloying process improve tensile strength (180–220 MPa) and suppress skin effect (Rac / Rdc≤1.15@10kHz). Corrugated shielding layer: Periodic corrugated structure enhances electromagnetic shielding (≥82dB@1MHz), and pre-embedded microchannels enable active heat dissipation (ΔT reduction ≥18℃@500A); Composite sheath: TPEE + carbon fiber composite material reduces the coefficient of friction (μ≤0.15 (tested according to DIN 53375 standard)), and the groove design increases the heat dissipation area by 20%.

[0070] With the combined effect of these three technologies, the bus power density is increased to 8.7kW / kg (compared to only 5.2kW / kg for traditional copper conductors), and the total life cycle cost is reduced by 42%, breaking through the limitations of single technology improvement.

[0071] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the scope of protection of the present invention.

Claims

1. A high power density compressed aluminum conductor wave-shaped shielded busbar for electric vehicles, characterized by: The application relates to a conductor layer, an insulating layer, a corrugated shielding layer and a sheath layer. The conductor layer is composed of micro-alloyed aluminum material with a compression rate of 30%-40%, a surface formed with a 2-10-micron dense oxide layer, the aluminum material is subjected to cold pressing and grain refining treatment, the tensile strength is 180-220 MPa, the elongation at break is greater than or equal to 15%, and the Rac / Rdc ratio is less than or equal to 1.15 under a 10-kHz high-frequency working condition; the tight pressing twisting process of the conductor layer is as follows: a circular single wire with a diameter of 0.5-1.0 mm is wound on a center conductor in a same direction twisting mode (all single wires are twisted in the same direction) to form an initial twisted structure; three-stage tight pressing die treatment is carried out, the cross-section height of each stage is reduced by 1 mm compared with the previous stage, a 50-80 MPa radial pressure is applied, and the twisting direction is left coaxial twisting, so that the single wire gap rate is reduced from 15%-20% to 8%-10%, and finally a flat conductor with a width-thickness ratio (the ratio of the conductor cross-section width to thickness) of 2:1 is formed, and the tight pressing coefficient is greater than or equal to 0.92; The insulating layer is coated on the conductor layer, is made of PA12 material with a temperature resistance of 125 DEG C, has a thickness of 0.5-1.5 mm, and is combined with the conductor layer surface through a double-layer co-extrusion process, and the peeling strength is greater than or equal to 25 N / cm; The corrugated shielding layer is composed of corrugated aluminum pipe with a wall thickness of 0.15-0.25 mm, a corrugated pitch of 5-8 mm, a depth of 2.0-3.0 mm, a wave angle of 50 DEG -70 DEG, and a ratio of the corrugated pitch to the conductor layer twisting pitch of 1:1.2, and the shielding effectiveness is greater than or equal to 82 dB at 1 MHz; The sheath layer is coated on the corrugated shielding layer, is formed by co-extrusion of a TPEE base and a flame-retardant PA12 outer layer, has a wall thickness of 2.0-3.0 mm, a surface friction coefficient mu less than or equal to 0.15, and a groove design for increasing the heat dissipation area by 20%.

2. The high power density compressed aluminum conductor wave-shaped shielded busbar for electric vehicles of claim 1, wherein, The micro-alloyed aluminum material of the conductor layer is added with rare earth elements through aging annealing process, the doping amount is 0.05-0.3 wt%, the conductor cross-section width-thickness ratio is 2:1, and the current-carrying capacity is greater than or equal to 680 A at 90 DEG C temperature rise.

3. The high power density compressed aluminum conductor wave-shaped shielded busbar for electric vehicles of claim 1, wherein, The corrugated valley of the corrugated aluminum pipe is pre-embedded with a micro-channel which is communicated with a dielectric fluid circulation system, the cross-section size is 0.3 mm*0.5 mm, the micro-channel is connected with the pipe of the dielectric fluid circulation system through an embedded flow guide joint, the flow guide joint adopts an expanded port sealing structure, the interface inner diameter is matched with the micro-channel cross-section size, the flow guide joint and the corrugated aluminum pipe are fixed through brazing process, and the heat dissipation efficiency is improved by greater than or equal to 35% (the temperature drop is reduced by greater than or equal to 18 DEG C) under a 500 A working condition.

4. The high power density compressed aluminum conductor wave-shaped shielded busbar for electric vehicles of claim 1, wherein, The TPEE base of the sheath layer is added with carbon fiber reinforced materials, the adding amount is 5-15 wt%, and the outer sheath is integrated with wave-absorbing materials, and an additional 10-15 dB electromagnetic shielding attenuation is provided.

5. A method of manufacturing a high power density corrugated shielded busbar for electric vehicles with compressed aluminum conductors as claimed in any one of claims 1 to 4, characterized in that, The application further relates to a preparation method of the conductor layer. The micro-alloyed aluminum material is subjected to three-stage pressing treatment, the compression rate of each stage is 10-15% (the total compression rate is 30%-40%), the pressing temperature is 150-200 DEG C, and the surface is subjected to micro-arc oxidation treatment to form a nanoscale conductive channel. (2) Insulation layer forming: PA12 material is once formed to cover the conductor layer by double-layer co-extrusion process, the co-extrusion temperature is 220-250℃, and the pressure is 8-12MPa; (3) Corrugated shielding layer processing: corrugated aluminum pipe is made of 3003 aluminum alloy strip through hydraulic forming process, micro-channel is embedded in the corrugated valley, and flow joint is fixed by brazing process, the corrugated depth is 2.0-3.0mm, and self-locking interface is adopted for connection; (4) Sheath layer compounding: TPEE matrix and flame-retardant PA12 outer layer are co-extruded to cover the corrugated shielding layer, the co-extrusion temperature is 180-200℃ and 240-260℃ respectively, and the surface groove structure is formed after cooling.

6. The preparation method according to claim 5, characterized in that, The grain size of the micro-alloyed aluminum material in step (1) is ≤5 μm, and the cold pressure welding interface resistance is ≤3.5 μΩ·cm 2 .

7. The preparation method according to claim 5, characterized in that, The forming pressure of the corrugated aluminum pipe in step (3) is 50-80MPa, and after forming, aging annealing treatment is carried out, the temperature is 180-220℃, the temperature is kept for 1-2 hours, and the negative Poisson's ratio characteristics of the corrugated unit make the radial compression expansion deformation ≥10% (according to ISO 6892-1 standard test, the radial pressure is 50MPa, the transverse expansion rate is 50MPa).

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