Brief introduction to the application status of aluminum conductor wire and cable for new energy vehicles

Copper core cable price is more expensive, heavy quality. The development of light weight and low price aluminum conductor wire and cable for automobiles is very necessary for lightweight design of automobiles. The traditional power industry uses aluminum cable for a long time, aluminum cable low cost, low quality, long service life, high voltage long distance transmission cable, in addition, China's aluminum resources are rich, material price fluctuations are small, the cost is stable and easy to control.

At present, automobile electrification and high voltage have become the development trend of the automobile industry, and the high voltage wiring harness is mainly copper wire. The existing high voltage wire harness has the characteristics of long conductor length, large conductor square number and high copper proportion. The application of high voltage aluminum wire provides a good solution to reduce the weight and cost of the vehicle wiring harness.

According to the overall structure, high-voltage aluminum wires can be divided into shielded high-voltage aluminum wires and unshielded high-voltage aluminum wires. According to the core structure, high-voltage aluminum wires can be divided into single-core high-voltage aluminum wires and multi-core high-voltage aluminum wires. High voltage aluminum wire is mainly composed of outer insulation layer, aluminum foil layer, shielding layer, inner insulation layer, aluminum wire core and so on. Compared with low-voltage wires, the structure of high-voltage aluminum wires is more complex, the material requirements are more stringent, and the manufacturing process requirements are higher, so the industry entry threshold is higher.

In the composition of high voltage aluminum wires, the role of the wire core is to conduct electricity. The role of the aluminum foil layer is high-frequency shielding to avoid interference with the core. The function of the shield layer is to prevent the electric field generated inside the wire from interfering with the outside world. When the insulation layer is damaged, it is used as a short-circuit current channel to reduce safety risks. The function of the insulation layer is mainly to isolate the wire or wire core from other conductors to prevent short circuit; Protect core and wire to avoid wear, dust and waterproof; Prevent human electrocution; Improve wire service life.

At present, the industry is exploring the application of high-voltage aluminum wires, and aluminum cables have been applied in foreign automotive fields. Domestic host manufacturers have gradually shown the demand for aluminum cable development and application intentions. The main users of wire harnesses such as Ningde Times and BYD have explored the application of aluminum high voltage wire harnesses, and the future of aluminum high voltage wire harnesses is bound to be the application direction of high voltage wire harnesses.

As a wiring harness material for new energy electric vehicles, aluminum wire has been the focus of attention in the industry because of its weak conductivity. When discussing how to solve this problem, we need to start from multiple angles and consider materials, processes, design and other aspects.

First | Material

We can improve the conductivity of aluminum wire by alloying. For example, adding an appropriate amount of alloying elements such as magnesium and silicon to aluminum can effectively improve the conductive properties of aluminum. This is because these alloying elements can refine the grain structure of aluminum, reduce the scattering of electrons at the grain boundaries, thereby reducing resistance and improving conductive efficiency.

In addition to alloying, we can also optimize the electrical conductivity of aluminum wires through heat treatment processes. Heat treatment can change the microstructure of aluminum, eliminate the internal stress, and further improve its electrical conductivity. Of course, this requires precise control of the heat treatment temperature and time to avoid excessive thermal damage to the aluminum wire.

Second | Technology

We can use advanced wire harness processing technology, such as ultrasonic welding, cold crimping, etc., to reduce the resistance at the wire harness connection and improve conductive efficiency. These technologies ensure the stability and reliability of wiring harness connections while reducing resistance and improving overall conductivity.

China Aluminum Industry Exhibition discusses the application cases of aluminum wire products

Great square automobile wire and cable will take the lead in switching to aluminum conductor cable products, and the practical application of mature aluminum cable products on the market is as follows.

1) Ultrasonic welding aluminum wire is used inside/outside the battery pack of bus models, and the large diameter power connection wire of bus models is used more, and the use of aluminum wire has obvious advantages.

2) The DC bus of the passenger model adopts 50mm2 aluminum cable, which has been successfully mass-produced. Ultrasonic welding can effectively improve the electrical contact performance of the joint, and effectively reduce the quality of the wire harness compared with the copper wire.

3) AC charging gun using high-strength bending aluminum alloy wire, light weight, aging test performance is stable, has gradually begun mass production; The DC charging port cable of passenger car uses aluminum wire to improve heat dissipation, and the circular charging port terminal uses ultrasonic welding to significantly improve the electrical contact performance, reduce the heat output, and improve the service life.

Third | Design

We can reduce the resistance by optimizing the layout and structure of the wiring harness. For example, the use of flat design of aluminum wire can reduce space occupation, reduce resistance; At the same time, the conductive aluminum bank arranged close to the bottom of the car can reduce the chassis bulge caused by the wire, which is both beautiful and practical.

Of course, solving the problem of weak conductive capacity of aluminum wire is not an overnight task, and we need to continue to explore and innovate in practice. We can learn from the successful experience in other fields, such as aluminum wire application cases in aerospace, power transmission and other fields, to draw inspiration and inspiration.

In this process, we also need to focus on interdisciplinary cooperation and exchanges. The knowledge and technology of materials science, physics, mechanical engineering and other disciplines can provide us with ideas and methods to solve problems. Through interdisciplinary cooperation and exchange, we can gather the wisdom and strength of all parties to jointly promote the improvement of electrical conductivity of new energy electric vehicle wiring harness materials.