What conductor structures are commonly used in power cables?
Common conductor structures for power cables include solid conductors, stranded round conductors, stranded compressed round conductors, and stranded shaped conductors.
The following principles are generally followed when selecting conductor structures for low-voltage power cables:
1) Solid conductors are typically used for conductors with a nominal cross-sectional area of 6mm or less. This is because the manufacturing process requires one less stranding step than for solid conductors, and the electrical properties of the finished products (20°C DC resistance) are very similar. Therefore, solid conductors offer significant advantages in improving production efficiency and reducing production costs for small-section conductors.
2) Stranded conductors are used for conductors with a nominal cross-sectional area of 10mm or greater. Generally, single-core cables with a conductor cross-sectional area of 35 mm or less use stranded round conductors, while cables with a conductor cross-sectional area of 50 mm or greater use stranded compressed round conductors. Multi-core cables with a conductor cross-sectional area of 35 mm or less use stranded round conductors, while cables with a conductor cross-sectional area of 50 mm or greater use stranded shaped conductors (semi-circular, sector-shaped, and tile-shaped).
Stranded shaped conductors are compact, with a smaller outer diameter than stranded round conductors. They also require less material in the various post-stranding steps, resulting in lower costs and a price advantage.
Medium-voltage power cables commonly use stranded compressed round conductors. This is primarily to prevent the conductor shield from embedding into the conductor, causing uneven electric field distribution and thus shortening the product's service life.
