High-Voltage Harnesses and Connectors

I. High-Voltage Harness Design Scheme

(1) Design Direction

This design scheme accurately targets the unique requirements of new energy vehicles and ingeniously presents a set of high-voltage harness solutions that combine high efficiency and high safety. By deeply optimizing the harness layout, carefully selecting suitable materials, and introducing advanced manufacturing processes, the goal of lightweighting high-voltage harnesses has been successfully achieved while ensuring efficient power transmission, laying a solid foundation for the excellent performance of new energy vehicles.

(2) Harness Layout Design

In the layout planning of the complex structure of the new energy vehicle chassis, the design of the routing of the high-voltage harness is extremely elaborate. Every bend and every stretch has been precisely calculated to ensure that its length is just right, eliminating the situations of being too long or too short. In this way, the adverse effects caused by vibration and friction on the harness during vehicle operation can be minimized. With the help of specially made harness fasteners, such as precisely designed clamps and stable and reliable brackets, the harness can remain as steady as a rock during the vehicle's high-speed driving and be firmly fixed in the predetermined position, effectively avoiding risks such as loosening and falling off. Moreover, for the key parts of the harness that are extremely vulnerable to wear or may be exposed to the encroachment of the external complex environment, adding protective sleeves is undoubtedly a wise move. This will greatly reduce the risk of damage and comprehensively extend the service life of the entire harness system, making its reliability achieve a qualitative leap.

(3) Material Selection

The choice of conductor materials is a crucial link related to the performance of high-voltage harnesses. Priority is given to materials with ultra-high conductivity, excellent heat resistance, and outstanding corrosion resistance, such as high-temperature superconducting materials or special alloy wires. Even in extremely harsh environments such as high-temperature roasting and high-humidity erosion, they can remain stable and ensure the stable and efficient transmission of electrical energy. The selection of insulating materials is equally important. Focusing on the high-performance field, materials such as polyimide (PI) and polytetrafluoroethylene (PTFE) stand out. With their extraordinary electrical insulation properties, they build an impregnable safety barrier for high-voltage power transmission. For connectors, high-strength and highly conductive metal materials such as copper alloys and stainless steel are the best choices, ensuring that the connectors can always maintain excellent contact performance during the long service cycle, escorting the smooth flow of current.

(4) Manufacturing Process

Introducing automated production technology to empower the manufacturing of high-voltage harnesses is like injecting a strong dose of stimulant into the production line. While greatly improving production efficiency, it comprehensively guarantees product quality. With precision crimping equipment, the conductor and the connector can achieve seamless connection and be tightly connected, effectively curbing the temperature rise problem caused by contact resistance from the source. Throughout the entire production process, strict quality inspections run through. From the accurate measurement of conductor resistance to the repeated verification of connector insertion and extraction forces, multiple test indicators are strictly checked to ensure that all performance indicators of the high-voltage harness accurately meet the established design standards, driving new energy vehicles forward with excellent quality.

(5) Safety Design

In the architecture of the high-voltage harness system, over-current protection devices are like loyal guards. Devices such as fuses and circuit breakers perform their respective duties to closely prevent damage to the harness caused by excessive current. At the same time, a solid "isolation wall" must be built between the high-voltage harness and the low-voltage harness and control harness to effectively block electromagnetic interference and nip potential safety risks in the bud. The design of the grounding system is even more crucial. With reasonable planning and careful layout, it is sure that the high-voltage harness can be firmly rooted in the ground to achieve reliable grounding, thereby minimizing the hidden dangers brought by electromagnetic interference and static electricity accumulation and escorting the safe operation of new energy vehicles.

II. Design and Layout of High-Voltage Harnesses

The layout design of high-voltage harnesses needs to strictly adhere to a series of basic norms, including safety, reliability, cost-effectiveness, and maintenance convenience. From the safety dimension, the harness must maintain a safe distance from heat sources and dynamic components to stay away from potential fire risk sources and ensure everything is foolproof. At the reliability level, it is required that the harness connection is as firm as a rock and can withstand the successive tests of environmental factors such as vibration, sudden temperature changes, and humidity. While pursuing excellent performance, economic factors cannot be ignored. Designers need to be meticulous in calculation and try their best to reduce the amount of harness and optimize the material consumption to achieve effective cost control. In terms of maintenance convenience, the harness layout should be neat and orderly, and the markings should be clear and conspicuous, facilitating maintenance personnel to quickly locate problems and efficiently complete replacement work, providing strong support for the later operation and maintenance of new energy vehicles.

III. Manufacturing Process and Material Selection of High-Voltage Harnesses

(1) Manufacturing Process

The manufacturing of conductors is like a delicate symphony of processes, with multiple steps working closely together. First, the wire drawing machine shows its prowess and precisely stretches the metal raw material into single wires of the specified diameter. Each single wire bears the important task of power transmission. Immediately after that, the annealing process comes on stage and endows the single wire with just the right softness, making it easier for subsequent processing. Subsequently, multiple single wires, like closely united comrades, are twisted into a strong wire core, and the mechanical strength soars instantly. The insulation process is equally not to be sloppy. With the help of the extruder, the insulating material is evenly coated on the outside of the conductor. After cooling and solidification, a firm insulating layer is formed to safeguard the pure transmission of electrical energy. The manufacturing of the shielding layer is even more critical. Materials such as metal braided nets or aluminum foils are tightly wrapped around the insulating layer to ensure close contact with the conductor and keep electromagnetic interference at bay. The connectors installed at both ends of the high-voltage harness are the key hubs connecting the vehicle's electrical systems. Relying on precision machining and injection molding technologies, super precision is ensured. During assembly, the conductor and the connector are tightly embraced, the contact resistance is reduced to the minimum, and the conductive performance is excellent.

(2) Material Selection

Conductor Materials:

On the design stage of high-voltage harnesses for new energy vehicles, high-purity copper and aluminum are the leading actors, jointly dealing with the severe challenges of large-current and high-voltage transmission. Copper conductors, with their outstanding conductive performance and excellent mechanical strength, are the first choice in most scenarios. In some specific application scenarios, lightweight and cost-effective aluminum conductors also stand out with their own advantages. To ensure the safe use of high-voltage harnesses, the outer layer of the conductor is carefully wrapped with insulating materials. Cross-linked polyethylene (XLPE), polyvinyl chloride (PVC), ethylene-propylene rubber (EPR), etc. each play their roles. Among them, cross-linked polyethylene is highly favored in the field of new energy vehicles due to its excellent electrical performance and heat resistance characteristics.

Shielding Materials:

In the wave of automotive manufacturing technology, to resist the invasion of electromagnetic interference (EMI) on vehicle electronic systems, high-voltage harnesses are equipped with special "electromagnetic armors". Shielding materials such as metal braided nets, aluminum foils, and conductive fabrics each use their unique skills to absorb or block electromagnetic waves, working together to minimize electromagnetic interference and escort the stable and reliable operation of vehicle electronic systems.

Jacket Materials:

The jacket serves as a solid shield for high-voltage harnesses and shoulders the important task of resisting the adverse effects of the external environment. Weather resistance, abrasion resistance, oil resistance, and flame retardancy are all indispensable. Materials such as polyvinyl chloride (PVC), thermoplastic elastomer (TPE), and nylon each dominate the market. Although they have different characteristics, they all aim to provide necessary protection to maintain the normal operation of high-voltage harnesses.

(3) Connector Selection Analysis

1. Performance Requirements of Connectors

Electrical Performance Requirements:

The design blueprint of connectors for new energy vehicles is carefully drawn around specific electrical performance requirements, aiming to ensure safety and stability in the high-voltage system. Considering the increasing voltage requirements of new energy vehicles, the rated voltage of connectors firmly crosses the 200V threshold, providing a solid guarantee for high-voltage power transmission. Insulation resistance is the "nemesis" of leakage and short circuits. Its value strictly follows industry standards, not less than 100 MΩ, guarding the pure passage of power transmission. The withstand voltage performance is even more important. It must be able to withstand the severe test of at least 1000V voltage to gain a firm foothold in the high-voltage system of new energy vehicles and ensure application safety.

Mechanical Performance Requirements:

Insertion and extraction force, as a key measurement index of the operation convenience of connectors, is delicately balanced in design. It should be easy to insert and extraction while avoiding excessive looseness. Usually, it is precisely controlled within 100 N. Mechanical durability defines the toughness of connectors. Ideally, the number of repeatable insertion and extraction times far exceeds 50 times. Even after years of grinding, it remains as stable as a mountain. During the driving of new energy vehicles, vibration is always present. Connectors, with their excellent anti-vibration ability, keep their electrical and mechanical performances unchanged under the specified vibration frequency and amplitude, ensuring the continuous stability of power transmission.

Temperature Adaptability Requirements:

The temperature adaptability of connectors is extremely strict. It needs to be able to operate normally within a wide temperature range from -40°C to 125°C. Whether it is icy and snowy or extremely hot, its electrical and mechanical performances always remain stable and never degenerate or fail. With steel-like reliability, it provides a solid backing for the operation of new energy vehicles in various extreme environments.

Corrosion Resistance Requirements:

The selection of connector materials directly affects the corrosion resistance performance. For the shell, aluminum or zinc alloy and other metal materials with excellent corrosion resistance are preferred, and the surface sandblasting treatment further strengthens the protection. For the contact part, red copper is selected, and processes such as gold plating, silver plating, and nickel plating are adopted. While meeting the corrosion prevention requirements, the conductivity is greatly improved. Good sealing performance is essential. It is like an impregnable defense line, strictly preventing the intrusion of harmful substances such as water anddust and effectively avoiding corrosion risks. In the design process, the sealing structure is carefully crafted to ensure perfect sealing effect in any harsh environment. In addition, multiple protective measures such as coating anti-corrosion coatings on the connector surface and using special sealing wraps are implemented, and regular maintenance and inspection are not slack. All-round efforts are made to ensure the long-term corrosion resistance of connectors, tight insertion, and never loosening.

2. Types and Characteristics of Connectors

Main Types of Connectors:

Dominating the domestic market, LV standard connectors, with their strictly optimized process standards, exhibit almost perfect perfection and easily meet diversified electrical connection requirements. Their versatility is outstanding. In the connection of core components of new energy vehicles, such as battery packs and motor controllers, they can play a major role, ensuring the stable and reliable operation of these components and injecting continuous vitality into the power heart of new energy vehicles.

USCAR Standard Connectors:

As an internationally certified interface device, USCAR standard connectors are renowned in the global new energy vehicle field due to their excellent compatibility and reliability. Their design strictly follows the stringent specifications of the automotive industry and can maintain stable operation even in extreme environments, providing solid support for international well-known new energy vehicle brands to compete in the global market and meeting the diversified demands of the global market.

Japanese Standard Connectors:

Japanese standard connectors are meticulously crafted in accordance with Japanese standards and are famous for their refinement and high performance. They are compact in size but contain huge energy, and their electrical performance is outstanding, ensuring the stable operation of equipment and excellent reliability, providing a high-quality choice for new energy vehicles pursuing ultimate performance.

General characteristics of connectors:

The efficient operation of new energy vehicles is inseparable from the stable power transmission of the high-voltage system, which requires the connector to have a strong "resistance" ability to calmly cope with the impact of high voltage and large current. The appropriate selection of insulating materials has become a key line of defense to prevent leakage and short circuit problems and ensure system safety. In addition, the electrical performance of the connector remains as solid as a rock under the "test" of high temperature and is not affected at all. In order to facilitate later maintenance and replacement, the design of the connector fully considers the requirements of easy installation and disassembly, which provides convenience for the full life cycle management of new energy vehicles.