Shielding and noise reduction method for high-voltage wiring harness of new energy automobile

Abstract

The invention discloses a shielding and noise reduction method for a high-voltage wiring harness of a new energy automobile, and relates to the technical field of computer-aided engineering, and the method comprises the following steps: employing three-dimensional full-wave electromagnetic simulation to recognize a noise source frequency characteristic and a coupling path, and building an electromagnetic interference model; designing a composite shielding structure and core parameters, and matching with an insulating buffer layer and a flame-retardant protective layer; optimizing the parameter combination through electromagnetic simulation; designing a grounding scheme according to the characteristics of the wire harness to form a low-impedance loop; the wiring harness trend and the fixing mode are optimized, and the wiring harness spacing is controlled; the shielding layer and the grounding terminal are connected by adopting an ultrasonic welding process, and a standardized process specification is formed through a multi-process test. Through simulation optimization, structural design, process compensation and full-process verification, the shielding accuracy and environmental adaptability are improved, the stability under vibration and aging working conditions is enhanced, the shielding defect is made up, the electromagnetic compatibility of the whole vehicle is guaranteed, and the problems that an existing method is extensive in design and insufficient in reliability are solved.

Description

Technical Field

[0001] This invention relates to the field of computer-aided engineering technology, and in particular to a method for shielding and reducing noise in high-voltage wiring harnesses for new energy vehicles. Background Technology

[0002] The rapid development of new energy vehicles has driven the widespread application of high-voltage electrical systems. High-voltage wiring harnesses, as energy transmission carriers for core components such as power batteries, motor controllers, and inverters, operate at voltages of hundreds of volts and currents of hundreds of amperes, making them prone to generating strong electromagnetic interference during operation. This electromagnetic interference not only affects the normal operation of sensitive electronic devices such as vehicle radar, navigation, and communication systems, leading to signal distortion and malfunction, but may also interfere with the stable operation of the entire vehicle control system, causing safety hazards. Furthermore, the compact interior space of new energy vehicles, the small spacing between high-voltage wiring harnesses and various electronic components, and the complex electromagnetic coupling paths further exacerbate the electromagnetic interference problem, becoming a key bottleneck restricting the improvement of electromagnetic compatibility performance in new energy vehicles.

[0003] Existing shielding and noise reduction methods for high-voltage wiring harnesses in new energy vehicles have many limitations. During the design phase, most methods rely on engineering experience to select shielding structures and parameters, lacking precise optimization based on electromagnetic simulation. Parameters such as shielding material selection, thickness, and braiding density do not match actual interference characteristics, leading to insufficient shielding effectiveness or over-design and wasted costs. While some methods incorporate electromagnetic simulation, they only consider electromagnetic field factors, neglecting the heating effect of the high-voltage wiring harness during operation and the vibration impact of vehicle movement. The conductivity of the shielding material decreases with temperature changes, and the braided structure is prone to deformation and wear during vibration, resulting in significant deviations between actual shielding performance and design expectations. Furthermore, the grounding system design lacks coordination with the shielding layer; the grounding scheme is fixed and cannot be dynamically adjusted according to interference frequency and wiring harness length. Excessively high grounding impedance can cause shielding failure, resulting in poor common-mode interference suppression.

[0004] At the level of wire harness layout and process implementation, existing methods lack quantitative spacing design guidelines. The arrangement of high-voltage wire harnesses and sensitive components relies entirely on experience, and excessively long parallel arrangements can exacerbate coupling interference. Inadequate design of fixed clip spacing and clamping force leads to poor contact between the shielding layer and grounding terminal, as well as shielding layer wear and damage, creating electromagnetic leakage points due to vibrations during vehicle operation. Fixed welding process parameters fail to consider the effects of temperature and shielding layer resistance changes, resulting in excessive contact resistance at connection points and further weakening the shielding effect. Furthermore, existing methods lack comprehensive defect compensation, aging verification, and vehicle integration verification processes. Local defects in the shielding layer are difficult to detect and compensate for, and performance degradation during long-term use cannot be predicted. Some solutions meet laboratory test standards but deteriorate in electromagnetic compatibility performance under complex vehicle conditions, failing to meet practical application requirements and hindering the large-scale upgrading and application of high-voltage wire harness shielding and noise reduction technology for new energy vehicles. Summary of the Invention

[0005] This invention proposes a shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles to solve the problems mentioned in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles, comprising the following steps: Noise source and coupling path analysis steps: Use three-dimensional full-wave electromagnetic simulation technology to scan the operating environment of high-voltage wiring harnesses in new energy vehicles, identify the characteristics of key noise sources, complete the time-domain to frequency-domain conversion through Fourier transform, analyze the interference coupling path type, quantify the electromagnetic coupling strength between the wiring harness and surrounding electronic components, and establish an electromagnetic interference mathematical model. Parametric design steps for shielding structure: Determine the core parameters of the shielding layer based on the electromagnetic interference model, select an appropriate shielding structure according to the interference frequency range, set a polytetrafluoroethylene insulating buffer layer on the inner side of the shielding layer, and wrap a flame-retardant polyolefin protective layer on the outer side. Electromagnetic simulation optimization steps: Construct a three-dimensional simulation model of the high-voltage wire harness shielding system using finite element electromagnetic simulation software, input noise excitation parameters under different operating conditions, simulate the attenuation characteristics of the shielding layer for interference in different frequency bands, analyze the mapping relationship between shielding layer parameters and shielding effectiveness, adjust parameter combinations, and stabilize the attenuation effect; The design steps for the shielding layer and grounding are as follows: Select an appropriate grounding scheme based on the harness length and interference frequency characteristics, optimize the grounding location and conductor cross-sectional area to form a low-impedance loop, verify the grounding scheme's suppression characteristics for common-mode interference, and reduce the probability of shielding failure. Optimization steps for wiring harness layout and fixing: Plan the routing path of high-voltage wiring harnesses, bypass areas with strong interference sources, control the distance between wiring harnesses and sensitive electronic components, use anti-vibration fixing clips to install wiring harnesses, reserve bending buffer sections, and reduce shielding layer wear and contact impedance changes; Process implementation and performance testing steps: The shielding structure is processed according to the optimized parameters, the shielding layer and the grounding terminal are connected by ultrasonic welding, the shielding effectiveness and noise reduction performance under complex working conditions are tested, and a standardized shielding and noise reduction process specification is formed.

[0007] Furthermore, it also includes multi-field coupling simulation optimization steps, combining electromagnetic simulation, temperature field simulation and mechanical field simulation to analyze the impact of the heating effect of the high-voltage harness on the conductivity of the shielding layer material, monitor the temperature distribution and conductivity change rate of the shielding layer, and simulate the deformation law and contact state change of the shielding layer braided structure under vibration conditions.

[0008] Furthermore, it also includes a shielding layer defect compensation step, which uses eddy current testing technology to detect defects in the shielding layer, records the location, size and morphological parameters of the defects, establishes a shielding effectiveness attenuation compensation model based on the defect data, and compensates for the impact of defects by locally thickening the shielding layer, adding auxiliary shielding mesh or optimizing the grounding path for different defect types.

[0009] Furthermore, in the electromagnetic simulation optimization step, a precise calculation formula for shielding effectiveness is constructed. ,in For shielding effectiveness, The incident electric field strength is... The transmitted electric field intensity, The electrical conductivity of the material. The thickness of the shielding layer, To shield the resistivity of the material, For interference signal frequency, The structural coupling coefficient is... For the shielding layer weaving density, The diameter is the wire harness diameter.

[0010] Furthermore, in the shielding layer and grounding co-design step, a dynamic grounding resistance optimization strategy is adopted. The length and cross-sectional area of ​​the grounding conductor are dynamically adjusted according to the working current amplitude and interference frequency of the high-voltage line harness. In the critical interference frequency range, the grounding impedance is reduced by connecting a parallel high-frequency grounding capacitor. The grounding capacitor value is selected according to the interference frequency characteristics. Electromagnetic simulation is used to verify the suppression effect of different grounding schemes on common-mode interference.

[0011] Furthermore, in the wire harness arrangement and fixing optimization step, an electromagnetic interference attenuation method for wire harness spacing is constructed. ,in This is the amount of interference attenuation. The dielectric attenuation coefficient, The distance between the center axes of the wire harness. For the safety distance threshold, The length attenuation coefficient is... For the parallel arrangement length of the wire harness, This refers to the frequency of the interference signal.

[0012] Furthermore, it also includes a vibration adaptive shielding reinforcement step, which obtains vibration frequency and amplitude data of new energy vehicles during driving through whole vehicle road spectrum testing, uses silicone rubber elastic shielding connectors in the engine compartment and chassis vibration parts of high voltage wiring harnesses, designs a corrugated buffer connection structure between the shielding layer and the wiring harness core wires, and optimizes the spacing and clamping force parameters of the fixing buckles through mechanical simulation.

[0013] Furthermore, in the process implementation steps, a welding process parameter compensation formula is constructed. ,in For optimal welding parameters, Based on the welding parameters, This is the temperature compensation coefficient. This is the difference between the actual temperature and the standard temperature. Standard welding temperature, This is the resistance compensation coefficient. This is the difference between the actual resistance of the shielding layer and the standard resistance. As a standard resistor for the shielding layer, the welding parameters are dynamically adjusted by monitoring the temperature and resistance changes of the welding area every second in real time to ensure the conductivity of the connection between the shielding layer and the grounding terminal.

[0014] Furthermore, aging and reliability verification steps are included. The processed high-voltage harness is placed in a high and low temperature cycling environment of -40℃ to 85℃, a humid heat aging environment of 40℃ / 95%RH, and a 5% NaCl salt spray corrosion environment. Test conditions are set for 50 cycles of high and low temperature cycling, 1000 hours of humid heat aging, and 500 hours of salt spray corrosion. The shielding effectiveness changes at different aging stages are continuously monitored. The service life of the shielding system is predicted by fitting the accelerated aging test data. The shielding layer material formula and process parameters are optimized to address the performance degradation problems that occur during the aging process.

[0015] Furthermore, the process includes a vehicle integration verification step, where the optimized high-voltage wiring harness is installed on the actual vehicle. Electromagnetic compatibility (EMC) tests are conducted on the entire vehicle in accordance with GB / T18387-2017 "Electromagnetic Field Radiation Intensity Limits and Measurement Methods for Electric Vehicles". The interference level of the wiring harness on the vehicle's radar, navigation, and communication systems under different driving conditions is detected. EMC problems found during the tests are resolved by adjusting the wiring harness layout path, grounding position, or shielding layer parameters, thus forming a high-voltage wiring harness shielding and noise reduction implementation plan adapted to specific vehicle models.

[0016] Compared with existing technologies, the beneficial effects of this invention are: At the design optimization level, relying on three-dimensional full-wave electromagnetic simulation and multi-field coupling simulation technology, precise identification and quantitative analysis of noise sources and coupling paths are achieved. This breaks away from the traditional experience-based design mode, ensuring a high degree of matching between shielding layer parameters and interference characteristics, making the shielding structure design more targeted. Multi-field coupling simulation comprehensively considers electromagnetic, temperature, and mechanical factors, avoiding design deviations caused by single simulations and ensuring that the shielding system can maintain stable performance under complex operating conditions. Quantitative calculations of shielding effectiveness and interference attenuation provide a scientific basis for parameter adjustment. Dynamic optimization strategies for the grounding system enhance the synergistic protection effect with the shielding layer, reducing electromagnetic interference coupling strength from the source and significantly improving the accuracy and reliability of the shielding design.

[0017] At the structural and layout level, the composite design of the shielding layer, insulation buffer layer, and flame-retardant protective layer balances shielding performance, mechanical strength, and environmental resistance, adapting to the installation space and dynamic deformation requirements of high-voltage harnesses. Vibration-adaptive shielding enhancement design and optimized fixing clip parameters reduce shielding layer wear, breakage, and poor contact caused by vibration, maintaining consistent shielding performance under dynamic operating conditions. Defect compensation steps precisely locate and compensate for local defects in the shielding layer, preventing electromagnetic leakage and ensuring uniform and stable overall shielding effectiveness of the harness, thus building a robust electromagnetic protection barrier from a structural perspective.

[0018] At the process and verification level, a dynamic compensation mechanism for welding process parameters responds in real time to changes in temperature and resistance, ensuring the connection quality between the shielding layer and the grounding terminal and reducing the risk of shielding failure caused by contact resistance. The aging and reliability verification process comprehensively assesses the durability of the shielding system under harsh environments such as high and low temperatures, humidity, and salt spray. Accelerated aging tests predict service life, and optimized material formulations and process parameters improve long-term stability. Vehicle integration verification strictly adheres to industry standards, ensuring that the shielding and noise reduction solution is suitable for real-world vehicle conditions, effectively suppressing interference from high-voltage wiring harnesses to sensitive onboard electronic equipment, and guaranteeing that the vehicle's electromagnetic compatibility performance meets standards.

[0019] Overall, this invention, through innovation across the entire process of simulation, design, manufacturing, and verification, significantly improves the shielding effectiveness and noise reduction stability of high-voltage wiring harnesses, enhances environmental adaptability and long-term reliability, reduces the impact of electromagnetic interference on the vehicle's electronic systems, and ensures the safe operation of new energy vehicles. Standardized process specifications support the large-scale application of the technology while avoiding over-design to reduce costs, thus promoting the development of electromagnetic compatibility technology for high-voltage wiring harnesses in new energy vehicles towards precision, stability, and standardization, providing strong technical support for the high-quality development of the new energy vehicle industry. Attached Figure Description

[0020] Figure 1 This is a schematic block diagram of a shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles proposed in this invention. Figure 2 A bar chart comparing the welding contact resistance of different process schemes; Figure 3 A line graph showing the relationship between aging time and shielding effectiveness; Figure 4 A horizontal bar graph showing the common-mode interference suppression effect of different grounding methods; Figure 5 The graph shows the relationship between the number of vibrations and the damage rate of the shielding layer. Detailed Implementation

[0021] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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 this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The invention will now be described in further detail with reference to the accompanying drawings.

[0024] Reference Figures 1 to 5 A method for shielding and reducing noise in high-voltage wiring harnesses for new energy vehicles, comprising the following steps: Noise source and coupling path analysis steps: Three-dimensional full-wave electromagnetic simulation technology is used to scan the operating environment of high-voltage wiring harnesses in new energy vehicles, accurately identify the frequency characteristics and amplitude distribution of key noise sources such as motor controllers, inverters, and power batteries, complete the time-domain to frequency-domain conversion through Fourier transform, analyze the coupling path types of conducted interference and radiated interference, quantify the electromagnetic coupling strength between the wiring harness and surrounding electronic components, and establish an electromagnetic interference mathematical model that includes wiring harness length, arrangement spacing, dielectric constant of the environmental medium, and conductor cross-sectional area; Parametric design steps for shielding structure: Determine the core parameters of the shielding layer based on the electromagnetic interference model, select copper wire braiding, aluminum foil wrapping or copper wire-aluminum foil composite shielding structure according to the interference frequency range, design the shielding layer thickness, braiding density and coverage according to the interference amplitude, set a polytetrafluoroethylene insulating buffer layer on the inner side of the shielding layer, and wrap a flame-retardant polyolefin protective layer on the outer side to take into account both shielding performance and mechanical bending characteristics, and adapt to the deformation requirements of high voltage line harness installation space and dynamic working conditions. Electromagnetic simulation optimization steps: Construct a three-dimensional simulation model of the high-voltage wire harness shielding system using finite element electromagnetic simulation software, input noise excitation parameters under different operating conditions such as idling, acceleration, and constant speed, simulate the attenuation characteristics of the shielding layer for interference in different frequency bands, analyze the nonlinear mapping relationship between shielding layer parameters and shielding effectiveness, and adjust the parameter combination through a genetic algorithm to make the shielding effectiveness form a uniform and stable attenuation effect within the target frequency range. The design steps for the shielding layer and grounding are as follows: Select a single-end grounding, double-end grounding, or multi-point grounding scheme based on the length of the wire harness and the characteristics of the interference frequency. Optimize the grounding position and the cross-sectional area of ​​the grounding conductor to form a low-impedance loop between the shielding layer and the grounding system. Control the grounding impedance within a preset range. Verify the suppression characteristics of the grounding scheme for common-mode interference through electromagnetic simulation to reduce the probability of shielding failure caused by poor grounding. Optimization steps for wiring harness layout and fixing: Based on the electromagnetic compatibility layout of the whole vehicle, plan the routing path of the high-voltage wiring harness, bypass the strong interference source areas such as the engine and drive motor, control the minimum distance between the wiring harness and sensitive electronic components such as vehicle radar and navigation, use nylon anti-vibration fixing clips to install the wiring harness, the clip spacing is set according to the vibration frequency characteristics, and a specific length buffer section is reserved at the bending part to reduce the wear of the shielding layer and the change of contact impedance caused by vibration; Process implementation and performance testing steps: The high-voltage wire harness shielding structure is processed according to optimized parameters. The shielding layer and grounding terminal are connected by ultrasonic welding. The welding temperature, pressure and time parameters are controlled to ensure the conductivity continuity and mechanical strength of the connection. The shielding effectiveness in the frequency range of 10kHz-1GHz is tested by an electromagnetic shielding test system. The noise reduction performance under complex working conditions is tested by a whole vehicle bench test. A standardized shielding and noise reduction process specification including material selection, parameter design and process operation is formed.

[0025] This invention also includes a multi-field coupling simulation optimization step, which combines electromagnetic simulation, temperature field simulation and mechanical field simulation to analyze the impact of the heating effect of the high-voltage harness on the conductivity of the shielding layer material, monitor the temperature distribution and conductivity change rate of the shielding layer, and simulate the deformation law and contact state change of the shielding layer braided structure under vibration conditions. Based on the simulation results, the selection of shielding layer material and structural design are adjusted so that the shielding system maintains stable shielding performance under the multi-field coupling of heat, force and electromagnetic fields, and improves the accuracy and comprehensiveness of single simulation design.

[0026] This invention also includes a shielding layer defect compensation step, which uses eddy current testing technology to detect defects in the shielding layer such as broken braids, damaged aluminum foil, and loose joints. The location, size, and morphological parameters of the defects are recorded. Based on the defect data, a shielding effectiveness attenuation compensation model is established. For different defect types, the impact of defects is compensated by locally thickening the shielding layer, adding auxiliary shielding mesh, or optimizing the grounding path, so that the overall shielding effectiveness deviation of the wire harness is controlled within a reasonable range and the electromagnetic leakage level caused by local defects is reduced.

[0027] In this invention, the electromagnetic simulation optimization step involves constructing a precise calculation formula for shielding effectiveness. ,in For shielding effectiveness, The incident electric field strength is... The transmitted electric field intensity, The electrical conductivity of the material. The thickness of the shielding layer, To shield the resistivity of the material, For interference signal frequency, The structural coupling coefficient is... For the shielding layer weaving density, By quantifying the combined effects of material properties, structural parameters, and signal frequency on shielding effectiveness, the diameter of the wire harness is used to provide a quantitative basis for adjusting the shielding layer parameters, so that the shielding effectiveness within the target frequency range meets the design standards.

[0028] In this invention, the shielding layer and grounding co-design step employs a dynamic grounding resistance optimization strategy. The length and cross-sectional area of ​​the grounding conductor are dynamically adjusted based on the operating current amplitude and interference frequency of the high-voltage line harness. In the critical interference frequency range, the grounding impedance is reduced by connecting a parallel high-frequency grounding capacitor. The grounding capacitor value is selected according to the interference frequency characteristics. Electromagnetic simulation is used to verify the suppression effect of different grounding schemes on common-mode interference, so that the shielding layer and grounding system form a complete electromagnetic protection loop, thereby improving the common-mode interference suppression capability.

[0029] In this invention, the wire harness arrangement and fixing optimization step involves constructing a wire harness spacing electromagnetic interference attenuation method. ,in This is the amount of interference attenuation. The dielectric attenuation coefficient is calculated from the dielectric constant of the ambient medium. The distance between the center axes of the wire harness. For the safety distance threshold, The length attenuation coefficient is... For the parallel arrangement length of the wire harness, To determine the frequency of the interference signal, the minimum safe distance between the high-voltage harness and sensitive components is determined by quantifying the influence of spacing and parallel length on interference coupling. Combined with the overall vehicle layout, the routing is rationally planned to shorten the parallel arrangement length and reduce the coupling interference intensity.

[0030] This invention also includes a vibration adaptive shielding enhancement step. Vibration frequency and amplitude data of new energy vehicles during driving are obtained through whole vehicle road spectrum testing. Silicon rubber elastic shielding connectors are used in easily vibrating parts such as the engine compartment and chassis of the high-voltage wiring harness. A corrugated buffer connection structure is designed between the shielding layer and the wiring harness core wire. The spacing and clamping force parameters of the fixing buckle are optimized through mechanical simulation to improve the connection stability between the shielding layer and the core wire, reduce shielding layer wear, breakage or increased contact impedance caused by vibration, and maintain the consistency of shielding performance under dynamic working conditions.

[0031] In this invention, the process implementation step involves constructing a welding process parameter compensation formula. ,in For optimal welding parameters, Based on the welding parameters, This is the temperature compensation coefficient. This is the difference between the actual temperature and the standard temperature. Standard welding temperature, This is the resistance compensation coefficient. This is the difference between the actual resistance of the shielding layer and the standard resistance. As a standard resistor for the shielding layer, the welding parameters are dynamically adjusted by monitoring the temperature and resistance changes of the welding area in real time every second to ensure the conductivity of the connection between the shielding layer and the grounding terminal and reduce the risk of shielding failure caused by contact resistance.

[0032] This invention also includes aging and reliability verification steps. The processed high-voltage harness is placed in a high and low temperature cycling environment of -40℃ to 85℃, a humid heat aging environment of 40℃ / 95%RH, and a 5% NaCl salt spray corrosion environment. The test conditions are set to 50 cycles of high and low temperature cycling, 1000 hours of humid heat aging, and 500 hours of salt spray corrosion. The shielding effectiveness changes at different aging stages are continuously monitored. The service life of the shielding system is predicted by fitting the accelerated aging test data. In response to the performance degradation problem that occurs during aging, the shielding layer material formula and process parameters are optimized to improve the shielding stability and durability during long-term use.

[0033] This invention also includes a vehicle integration verification step, in which the optimized high-voltage wiring harness is installed on a real vehicle, and electromagnetic compatibility testing of the whole vehicle is carried out in accordance with GB / T18387-2017 "Limits and Measurement Methods for Electromagnetic Field Radiation Intensity of Electric Vehicles". The interference level of the wiring harness to the vehicle radar, navigation and communication systems under different driving conditions such as idling, acceleration and high speed is detected. Electromagnetic compatibility problems found in the test are solved by adjusting the wiring harness layout path, grounding position or shielding layer parameters, forming a high-voltage wiring harness shielding and noise reduction implementation scheme adapted to specific vehicle models, so that the electromagnetic compatibility performance of the whole vehicle fully meets the industry standards and vehicle design requirements.

[0034] The following two examples further illustrate specific embodiments of the present invention: Example 1: Application of shielding and noise reduction in high-voltage wiring harnesses for pure electric passenger vehicles This embodiment focuses on the high-voltage wiring harness from the power battery to the motor controller of a pure electric passenger vehicle. The wiring harness operates at a voltage of 350V and a current of 250A. The shielding and noise reduction method of this invention is applied to verify the effects of multi-field coupling simulation optimization, vibration adaptive shielding enhancement, and dynamic compensation of process parameters. It fully covers all technical solutions and achieves efficient shielding and noise reduction in the frequency range of 10kHz-1GHz.

[0035] 1. Noise Source and Coupling Path Analysis Three-dimensional full-wave electromagnetic simulation technology was used to scan the operating environment of the high-voltage wiring harness in the vehicle. The simulation frequency range was set to 10kHz-1GHz, with a step size of 100kHz. The frequency characteristics and amplitude distribution of the motor controller, inverter, and power battery were accurately identified. The main interference frequencies for the motor controller were 100kHz-5MHz, for the inverter 5MHz-50MHz, and for the power battery 10kHz-100kHz. A fast Fourier transform was used to complete the time-domain to frequency-domain conversion, with a sampling frequency of 2GHz to ensure conversion accuracy. Analysis showed that conducted interference mainly occurs through wire coupling within the wiring harness, while radiated interference occurs through spatial electromagnetic field coupling. The electromagnetic coupling strength between the wiring harness and the vehicle radar and navigation module was quantified. The initial distance between the vehicle radar and the wiring harness was 15cm, and the initial distance between the navigation module and the wiring harness was 12cm. A simulation model was established with a wiring harness length of 3.2m, a spacing of 10cm, an environmental dielectric constant of 2.2, and a conductor cross-sectional area of ​​16mm². 2 The electromagnetic interference mathematical model provides data support for subsequent design.

[0036] 2. Parametric design of shielding structure Based on the electromagnetic interference model, a copper wire-aluminum foil composite shielding structure was selected to meet the wide-frequency interference suppression requirements. The copper wire braided layer uses 0.1mm diameter oxygen-free copper wire with a braiding density of 90%, the aluminum foil layer is 0.08mm thick, and the total shielding layer thickness is 1.2mm. A 0.5mm thick polytetrafluoroethylene (PTFE) insulating buffer layer is placed inside the shielding layer, and a 1.0mm thick flame-retardant polyolefin protective layer is wrapped on the outside, achieving a flame-retardant rating of VW-1. Bending tests verified that this structure can accommodate a minimum bending radius of 80mm for the wiring harness, meeting the dynamic deformation requirements between the engine compartment and the chassis, and showed no cracking or detachment after 500 repeated bending cycles.

[0037] 3. Electromagnetic Simulation Optimization and Formula Application A 3D simulation model of the high-voltage wiring harness shielding system was constructed using finite element method (FEM) electromagnetic simulation software, with a mesh size of 0.5mm to ensure simulation accuracy in the high-frequency band. Noise excitation parameters for idling, acceleration, and constant speed conditions were input: motor speed of 800 rpm for idling, 6000 rpm for acceleration, and 3000 rpm for constant speed, simulating the attenuation characteristics of the shielding layer against interference at different frequency bands. A precise formula for calculating shielding effectiveness was then constructed. ,in For shielding effectiveness, Assuming the incident electric field strength is 50 V / m, The transmission electric field strength is taken as 0.3 V / m. The conductivity of the copper wire material is taken as 0.8. The shielding layer thickness is set at 1.2mm. The resistivity of the copper wire is taken as 1.7 × 10⁻ 8 Ω・m, The frequency of the interference signal is set to 10MHz. The structural coupling coefficient is set to 0.6. The braiding density of the shielding layer is set to 90%. Assuming a wire harness diameter of 20mm, the calculation yields: By iterating the parameter combination 20 times using a genetic algorithm, the shielding effectiveness is uniformly and stably attenuated within the target frequency range.

[0038] 4. Coordinated design of shielding layer and grounding Based on the harness length of 3.2m and the interference frequency characteristics, a double-ended grounding scheme is selected. The grounding points are located at the positive and negative terminal junction boxes of the power battery and the outer casing of the motor controller. The cross-sectional area of ​​the grounding conductor is selected as 6mm². 2 In the critical interference frequency range of 10MHz-100MHz, a 100pF high-frequency grounding capacitor is connected in parallel to reduce the grounding impedance. Electromagnetic simulation verification shows that the common-mode interference suppression capability is significantly improved compared to the single grounding scheme.

[0039] 5. Optimization of wire harness layout and fixing Based on the vehicle's electromagnetic compatibility (EMC) layout, the high-voltage wiring harness is planned to run along the side of the chassis, bypassing the strong interference source area in the engine compartment, maintaining a minimum distance of 20cm from the vehicle radar and a minimum distance of 18cm from the navigation module. An EMC attenuation mechanism based on the wiring harness spacing is implemented. in This is the amount of interference attenuation. The dielectric attenuation coefficient is taken as 0.8, calculated from the dielectric constant of the ambient medium, which is 2.2. The initial spacing between the center axes of the wire harness is set to 12cm. The safety distance threshold is set at 18cm. The length attenuation coefficient is set to 0.5. The initial parallel arrangement length is taken as 0.8m. Taking the interference signal frequency as 10MHz, the calculation yields: Based on the calculation results, the layout was adjusted, and the length of the parallel layout was shortened to 0.3m. Nylon anti-vibration fixing buckles were used for installation, with the buckle spacing set at 30cm and a 5cm buffer section reserved at the bending parts.

[0040] 6. Process Implementation and Multi-Process Validation The shielding layer and grounding terminal were connected using ultrasonic welding. The welding temperature was set to 220℃, the pressure to 0.3MPa, and the time to 2s. A welding process parameter compensation formula was constructed. ,in For optimal welding parameters, The reference welding pressure is taken as 0.3 MPa. The temperature compensation coefficient is set to 0.2. The difference between the actual temperature and the standard temperature is taken as 15℃. The standard welding temperature is set at 220℃. The resistance compensation factor is set to 0.3. The difference between the actual resistance and the standard resistance of the shielding layer is taken as 0.02Ω. Taking the standard resistance of the shielding layer as 0.1Ω, the calculation yields: By monitoring temperature and resistance changes in real time, the welding pressure was dynamically adjusted to 0.37 MPa. Eddy current testing was used to inspect the shielding layer, revealing a 0.5 mm flaw. 2 For aluminum foil damage defects, a 0.3mm thicker shielding layer was used to compensate. The wire harness was subjected to 50 cycles of high and low temperature cycling from -40℃ to 85℃ and 1000 hours of humid heat aging at 40℃ / 95%RH, and the changes in shielding effectiveness were continuously monitored.

[0041] 7. Effect Testing and Data Comparison Table 1 compares the shielding and noise reduction performance of high-voltage wiring harnesses in pure electric passenger vehicles: Performance indicators Existing methods Method of the present invention Shielding effectiveness (10MHz) lower high Shielding stability after vibration Difference good Reliability of welded connections generally high Performance degradation after aging obvious slight Overall vehicle EMC compliance rate lower high Table 1 shows that existing methods rely on empirical design, resulting in insufficient shielding effectiveness and performance degradation due to shielding layer wear after vibration. Fixed welding parameters lead to connection reliability issues, and performance deteriorates significantly after aging, resulting in low overall vehicle EMC compliance rates. This invention precisely optimizes shielding parameters through electromagnetic simulation, ensures stability under complex operating conditions through multi-field coupling simulation, reduces wear through vibration adaptive design, improves connection quality through dynamic compensation of welding parameters, and reduces performance degradation through aging verification and defect compensation. This significantly improves the overall vehicle EMC compliance rate, fully meeting the shielding and noise reduction requirements of high-voltage wiring harnesses in pure electric passenger vehicles and effectively protecting the normal operation of sensitive onboard electronic equipment.

[0042] Example 2: Application of shielding and noise reduction for high-voltage wiring harnesses in electric commercial vehicles This embodiment focuses on the high-voltage wiring harness from the power battery to the inverter of an electric commercial vehicle. The wiring harness operates at 600V and 400A. The shielding and noise reduction method of this invention is applied to verify the vehicle integration verification, aging reliability and defect compensation effect. It fully covers all technical solutions and is suitable for the high current, long distance and harsh operating conditions of commercial vehicles.

[0043] 1. Noise Source and Coupling Path Analysis Three-dimensional full-wave electromagnetic simulation technology was used to scan the operating environment of high-voltage wiring harnesses in commercial vehicles. The simulation frequency range was 10kHz-1GHz, with a step size of 100kHz. The frequency characteristics and amplitude distribution of the power battery, inverter, and drive motor were identified. The main interference frequencies of the power battery were 10kHz-200kHz, the main interference frequencies of the inverter were 200kHz-100MHz, and the main interference frequencies of the drive motor were 100MHz-1GHz. Time-domain to frequency-domain conversion was performed using Fourier transform, with a sampling frequency of 2GHz. Analysis showed that conducted interference was coupled through the wiring harness core wires and the grounding loop, while radiated interference was coupled through conduction to the vehicle frame and spatial radiation. The electromagnetic coupling strength between the wiring harness and the vehicle communication system and braking control system was quantified. The initial distance between the vehicle communication system and the wiring harness was 25cm, and the initial distance between the braking control system and the wiring harness was 20cm. A simulation model was established with a wiring harness length of 8.5m, a spacing of 15cm, an environmental dielectric constant of 2.3, and a conductor cross-sectional area of ​​25mm². 2 Mathematical model of electromagnetic interference.

[0044] 2. Parametric design of shielding structure Based on an electromagnetic interference model, a copper wire braided shielding structure was selected, with copper wire diameter of 0.15mm, braiding density of 95%, and shielding layer thickness of 1.5mm. A 0.8mm thick polytetrafluoroethylene (PTFE) insulating buffer layer is placed inside the shielding layer, and a 1.2mm thick flame-retardant polyolefin protective layer is wrapped on the outside, achieving a flame-retardant rating of VW-1. Bending tests verified that this structure can accommodate a minimum bending radius of 100mm, meeting the requirements of complex layouts and dynamic deformations in commercial vehicle chassis.

[0045] 3. Electromagnetic Simulation Optimization and Formula Application A three-dimensional simulation model was constructed using finite element electromagnetic simulation software with a mesh size of 0.8 mm. Noise excitation parameters for idling, acceleration, and constant speed conditions were input. The motor speed was 600 rpm for idling, 4500 rpm for acceleration, and 2500 rpm for constant speed. These parameters were then substituted into the precise calculation formula for shielding effectiveness. For shielding effectiveness, Assuming the incident electric field strength is 80 V / m, The transmission electric field strength is taken as 0.2 V / m. The material conductivity is taken as 0.85. The shielding layer thickness is set at 1.5mm. The resistivity of the copper wire is taken as 1.7 × 10⁻ 8 Ω・m, The interference signal frequency is set to 50MHz. The structural coupling coefficient is set to 0.7. The braiding density of the shielding layer is set to 95%. Assuming the wire harness diameter is 28mm, the calculation yields: The parameter combination was optimized through 25 iterations using a genetic algorithm.

[0046] 4. Coordinated design of shielding layer and grounding Based on the harness length of 8.5m and the interference frequency characteristics, a multi-point grounding scheme was selected, with three grounding points set at the power battery end, the inverter end, and the middle section of the vehicle frame. The cross-sectional area of ​​the grounding conductor is 10mm². 2 In the critical interference frequency range of 50MHz-500MHz, a 200pF high-frequency grounding capacitor was connected in parallel. Electromagnetic simulation verified that the common-mode interference suppression effect was significantly improved.

[0047] 5. Optimization of wire harness layout and fixing The high-voltage wiring harness is planned to run along the side of the vehicle frame, bypassing the drive motor and engine areas, maintaining a minimum distance of 30cm from the onboard communication system and a minimum distance of 25cm from the braking control system. Substituting these values ​​into the electromagnetic interference attenuation formula based on the wiring harness spacing, where AI is the interference attenuation amount,... The dielectric attenuation coefficient is taken as 0.85, calculated from the dielectric constant of the ambient medium, which is 2.3. The initial center axis spacing of the wire harness is set at 15cm. The safety distance threshold is set at 25cm. The length attenuation coefficient is set to 0.6. The initial parallel arrangement length is taken as 1.2m. Taking the interference signal frequency as 50MHz, the calculation yields: After adjustment, the parallel arrangement length is shortened to 0.5m, and nylon anti-vibration fixing buckles are used for installation with a buckle spacing of 40cm and an 8cm buffer section reserved at the bending part.

[0048] 6. Process Implementation and Full-Process Verification The shielding layer and grounding terminal were connected using ultrasonic welding at a temperature of 230℃, a pressure of 0.4MPa, and a time of 2.5s. Substituting these welding process parameters into a compensation formula, where... For optimal welding parameters, The reference welding pressure is taken as 0.4 MPa. The temperature compensation coefficient is set to 0.25. The difference between the actual temperature and the standard temperature is taken as 20℃. The standard welding temperature is set at 230℃. The resistance compensation factor is set to 0.35. The difference between the actual resistance and the standard resistance of the shielding layer is taken as 0.03Ω. Taking the standard resistance of the shielding layer as 0.12Ω, the calculation yields: Welding pressure was monitored and adjusted to 0.51 MPa in real time. Eddy current testing was used to inspect the shielding layer, revealing two braided wire breakage defects, which were compensated for by adding an auxiliary shielding mesh. The harness was subjected to 50 cycles of high and low temperature cycling from -40℃ to 85℃, 1000 hours of damp heat aging at 40℃ / 95%RH, and 500 hours of salt spray corrosion with 5% NaCl, with continuous monitoring of changes in shielding effectiveness.

[0049] 7. Vehicle integration verification and performance testing The optimized high-voltage wiring harness was installed in the actual vehicle, and electromagnetic compatibility (EMC) testing was conducted on the entire vehicle in accordance with GB / T18387-2017 "Limits and Measurement Methods for Electromagnetic Field Radiation Intensity of Electric Vehicles". The interference level of the wiring harness on the vehicle communication, braking control and other systems was tested under idling, acceleration and high-speed conditions. By adjusting the grounding position and shielding layer parameters, two EMC issues found in the test were resolved, and a shielding and noise reduction implementation plan adapted to this commercial vehicle was formed.

[0050] Table 2 compares the shielding and noise reduction performance of high-voltage wiring harnesses in electric commercial vehicles. Performance indicators Existing methods Method of the present invention Common-mode interference suppression effect generally good Long-distance shielding stability Difference high Salt spray corrosion resistance weak powerful Overall vehicle EMC compliance rate lower high Defect compensation effectiveness none have Table 2 shows that existing methods struggle to address interference issues caused by long-distance, high-current high-voltage wiring harnesses in commercial vehicles. They suffer from poor shielding stability after long-distance transmission, are prone to failure under salt spray corrosion, lack defect compensation mechanisms, and result in low overall vehicle EMC compliance rates. This invention, through a multi-point grounding and high-frequency capacitor collaborative design, strengthens common-mode interference suppression. Optimized shielding structure and fixing methods improve long-distance transmission stability. Salt spray corrosion resistance is significantly enhanced through a special protective layer and aging verification. The defect compensation mechanism effectively prevents electromagnetic leakage, resulting in a substantial improvement in overall vehicle EMC compliance rates. This method is fully adaptable to the harsh operating conditions and long-distance transmission requirements of electric commercial vehicles, ensuring stable operation of the vehicle's electrical system and reducing the risk of failure.

[0051] Reference Figure 2 The bar chart clearly compares the contact resistance performance of various welding processes. Traditional fixed-parameter welding, which does not consider real-time changes in temperature and shielding layer resistance, results in a contact resistance of up to 8mΩ; manual welding, affected by operational errors, has a resistance as high as 12mΩ; laser welding, although highly precise, is expensive, and still has a resistance of 5mΩ. This invention's dynamic compensation welding, by monitoring temperature and resistance changes in real time and adjusting welding parameters, achieves a contact resistance of only 2mΩ, significantly reducing the risk of shielding failure caused by contact resistance, improving the conductivity continuity between the shielding layer and the grounding terminal, and ensuring connection reliability while maintaining economic efficiency, providing process support for the stable operation of high-voltage wire harness shielding systems.

[0052] Reference Figure 3 The line graph combined with the trend line illustrates the degradation of shielding effectiveness during the aging process. Existing methods show a rapid decline in effectiveness with increasing aging time, with only 12dB remaining after 800 hours, which cannot meet the performance requirements for long-term use of high-voltage wiring harnesses. This invention, through optimized shielding layer material formulation and structural design, maintains an effectiveness of 51dB after 800 hours of aging, with a degradation of less than 8%. This is attributed to the anti-aging protection of the flame-retardant protective layer on the outside of the shielding layer and the structural stability of the inner buffer layer, effectively slowing down the aging rate of the material, ensuring the shielding effect of the high-voltage wiring harness throughout its entire life cycle, and improving the long-term reliability of high-voltage systems in new energy vehicles.

[0053] Reference Figure 4 The horizontal bar chart visually presents the common-mode interference suppression capabilities of various grounding methods. Existing single-ended grounding, double-ended grounding, and traditional multi-point grounding methods have limited suppression effects, with a maximum of only 22dB. This invention's optimized multi-point grounding, combined with high-frequency grounding capacitor compensation, achieves a suppression of 35dB, significantly improving the common-mode interference suppression effect. This is because this invention dynamically designs the location, number, and capacitance parameters of grounding points based on the harness length and interference frequency characteristics, forming a low-impedance grounding loop that effectively blocks the conduction path of common-mode interference. This solves the technical pain point of difficult common-mode interference suppression in high-voltage harnesses of new energy vehicles, improving the overall vehicle electromagnetic compatibility performance.

[0054] Reference Figure 5 This line graph reflects the changing trend of the shielding layer damage rate under vibration conditions. Existing fixing methods, due to unreasonable clip spacing and lack of buffer structure, result in a 30% damage rate after 200,000 vibrations, easily leading to electromagnetic leakage. This invention employs an elastic shielding connector and an optimized clip spacing design, maintaining a damage rate consistently below 4%, demonstrating excellent vibration resistance. This design is suitable for the complex vibration conditions encountered by new energy vehicles during operation, preventing the shielding layer from wearing and breaking due to vibration, maintaining the structural integrity of the shielding system, and ensuring the stability of the high-voltage wiring harness shielding and noise reduction effect under dynamic conditions.

[0055] The above are merely preferred embodiments 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 inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for shielding and reducing noise in high-voltage wiring harnesses for new energy vehicles, characterized in that, Includes the following steps: Noise source and coupling path analysis steps: Use three-dimensional full-wave electromagnetic simulation technology to scan the operating environment of high-voltage wiring harnesses in new energy vehicles, identify the characteristics of key noise sources, complete the time-domain to frequency-domain conversion through Fourier transform, analyze the interference coupling path type, quantify the electromagnetic coupling strength between the wiring harness and surrounding electronic components, and establish an electromagnetic interference mathematical model. Parametric design steps for shielding structure: Determine the core parameters of the shielding layer based on the electromagnetic interference model, select an appropriate shielding structure according to the interference frequency range, set a polytetrafluoroethylene insulating buffer layer on the inner side of the shielding layer, and wrap a flame-retardant polyolefin protective layer on the outer side. Electromagnetic simulation optimization steps: Construct a three-dimensional simulation model of the high-voltage wire harness shielding system using finite element electromagnetic simulation software, input noise excitation parameters under different operating conditions, simulate the attenuation characteristics of the shielding layer for interference in different frequency bands, analyze the mapping relationship between shielding layer parameters and shielding effectiveness, adjust parameter combinations, and stabilize the attenuation effect; The design steps for the shielding layer and grounding are as follows: Select an appropriate grounding scheme based on the harness length and interference frequency characteristics, optimize the grounding location and conductor cross-sectional area to form a low-impedance loop, verify the grounding scheme's suppression characteristics for common-mode interference, and reduce the probability of shielding failure. Optimization steps for wiring harness layout and fixing: Plan the routing path of high-voltage wiring harnesses, bypass areas with strong interference sources, control the distance between wiring harnesses and sensitive electronic components, use anti-vibration fixing clips to install wiring harnesses, reserve bending buffer sections, and reduce shielding layer wear and contact impedance changes; Process implementation and performance testing steps: The shielding structure is processed according to the optimized parameters, the shielding layer and the grounding terminal are connected by ultrasonic welding, the shielding effectiveness and noise reduction performance under complex working conditions are tested, and a standardized shielding and noise reduction process specification is formed.

2. The shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles according to claim 1, characterized in that, It also includes multi-field coupling simulation optimization steps, combining electromagnetic simulation, temperature field simulation and mechanical field simulation to analyze the impact of the heating effect of the high-voltage harness on the conductivity of the shielding layer material, monitor the temperature distribution and conductivity change rate of the shielding layer, and simulate the deformation law and contact state change of the shielding layer braided structure under vibration conditions.

3. The shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles according to claim 1, characterized in that, It also includes a shielding layer defect compensation step, which uses eddy current testing technology to detect defects in the shielding layer, records the location, size and morphological parameters of the defects, establishes a shielding effectiveness attenuation compensation model based on the defect data, and compensates for the impact of defects by locally thickening the shielding layer, adding auxiliary shielding mesh or optimizing the grounding path for different defect types.

4. The shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles according to claim 1, characterized in that, In the electromagnetic simulation optimization step, a precise calculation formula for shielding effectiveness is constructed. ,in For shielding effectiveness, The incident electric field strength is... The transmitted electric field intensity, The electrical conductivity of the material. The thickness of the shielding layer, To shield the resistivity of the material, For interference signal frequency, The structural coupling coefficient is... For the shielding layer weaving density, The diameter is the wire harness diameter.

5. The shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles according to claim 1, characterized in that, In the design steps of shielding layer and grounding, a dynamic grounding resistance optimization strategy is adopted. The length and cross-sectional area of ​​the grounding conductor are dynamically adjusted according to the working current amplitude and interference frequency of the high-voltage line harness. In the critical interference frequency range, the grounding impedance is reduced by connecting a parallel high-frequency grounding capacitor. The grounding capacitor value is selected according to the interference frequency characteristics. Electromagnetic simulation is used to verify the suppression effect of different grounding schemes on common-mode interference.

6. The shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles according to claim 1, characterized in that, In the wire harness arrangement and fixing optimization step, a wire harness spacing electromagnetic interference attenuation method is constructed. ,in This is the amount of interference attenuation. The dielectric attenuation coefficient, The distance between the center axes of the wire harness. For the safety distance threshold, The length attenuation coefficient is... For the parallel arrangement length of the wire harness, This refers to the frequency of the interference signal.

7. The shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles according to claim 1, characterized in that, It also includes vibration adaptive shielding reinforcement steps, obtaining vibration frequency and amplitude data of new energy vehicles during driving through whole vehicle road spectrum testing, using silicone rubber elastic shielding joints in the engine compartment and chassis vibration parts of high voltage wiring harnesses, designing a corrugated buffer connection structure between the shielding layer and the wiring harness core wires, and optimizing the spacing and clamping force parameters of the fixing buckles through mechanical simulation.

8. The shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles according to claim 1, characterized in that, In the process implementation steps, a welding process parameter compensation formula is constructed. ,in For optimal welding parameters, Based on the welding parameters, This is the temperature compensation coefficient. This is the difference between the actual temperature and the standard temperature. Standard welding temperature, This is the resistance compensation coefficient. This is the difference between the actual resistance of the shielding layer and the standard resistance. As a standard resistor for the shielding layer, the welding parameters are dynamically adjusted by monitoring the temperature and resistance changes of the welding area every second in real time to ensure the conductivity of the connection between the shielding layer and the grounding terminal.

9. The shielding and noise reduction method for high-voltage wiring harnesses in new energy vehicles according to claim 1, characterized in that, It also includes aging and reliability verification steps, placing the processed high-voltage harness in a high and low temperature cycling environment of -40℃ to 85℃, a humid heat aging environment of 40℃ / 95%RH, and a 5% NaCl salt spray corrosion environment. The test conditions are set to 50 cycles of high and low temperature, 1000 hours of humid heat aging, and 500 hours of salt spray corrosion. The shielding effectiveness changes at different aging stages are continuously monitored. The service life of the shielding system is predicted by fitting the accelerated aging test data. The shielding layer material formula and process parameters are optimized to address the performance degradation problem that occurs during the aging process.

10. A method for shielding and reducing noise in high-voltage wiring harnesses for new energy vehicles according to claim 1, characterized in that, It also includes a whole vehicle integration verification step, where the optimized high-voltage wiring harness is installed on the actual vehicle, and whole vehicle electromagnetic compatibility testing is carried out in accordance with GB / T18387-2017 "Electromagnetic Field Radiation Intensity Limits and Measurement Methods for Electric Vehicles". The interference level of the wiring harness to the vehicle radar, navigation and communication systems under different driving conditions is detected. Electromagnetic compatibility problems found in the test are solved by adjusting the wiring harness layout path, grounding position or shielding layer parameters, and a high-voltage wiring harness shielding and noise reduction implementation plan adapted to specific vehicle models is formed.

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