The diameter of the high-voltage conductor is often several times that of the low-voltage conductor. In order to increase the flexibility and bendability of the high-voltage conductor, the conductor core with a larger interface is formed by twisting multiple single wires with smaller diameters. The wire core stranded by multiple single wires has good flexibility and large curvature. When the wire core is bent, the inner and outer parts of the center line of the wire core can move to compensate each other, and the plastic deformation of the conductor will not be caused during bending, so the softness of the wire core. The performance and stability are greatly improved. Therefore, vehicle wiring harnesses, especially high-voltage wires, are generally produced using stranded conductors.
The twisting form of the core can be divided into two types, regular twisting and irregular twisting.
(1) Regular twist
The wires have regular, concentric, and successive layers are twisted in different directions into regular twists.
Further, it can also be divided into normal regular stranding and abnormal regular stranding. The latter refers to the regular twisting of wires with different diameters between layers, and the former refers to the wires having the same diameter.
Regular twisting can also be subdivided into simple regular twisting and compound regular twisting. The latter refers to the fact that the wires that make up the regular twisting are not single, but thinner wires are twisted into strands according to the rules, and then twisted into wires. Core, this twist is mostly used to move the core of the rubber insulated cable to improve its flexibility.
(2) Irregular stranding
Refers to the twisting of all the constituent wires in the same direction.
The stranding of the core is also designed to other related process parameters, including stranding pitch, stranding coefficient, stranding direction, stranding law, etc.
Taking into account the production process and process requirements, the twisting method of high-voltage wires for electric vehicles is usually normal and regular twisting, which is conducive to mechanized and automated production.
