Power cable classification
By voltage rating
According to the voltage level, it can be divided into medium and low voltage power cable (35 kV and below), high voltage cable (110 kV or more), ultra high voltage cable (275 to 800 kV) and UHV cable (1000 kV and above). In addition, it can be divided into AC cable and DC cable according to current.
According to insulation material
1. Oil-immersed paper insulated power cable with oil-impregnated paper as insulation. Its application history is the longest. It is safe and reliable, has a long service life and is inexpensive. The main disadvantage is that the laying is limited by the drop. Since the development of non-drip paper impregnation insulation, the problem of drop limitation has been solved, and oil-impregnated paper insulated cables have continued to be widely used.
2, plastic insulation power cable insulation layer is extruded plastic power cable. Commonly used plastics are polyvinyl chloride, polyethylene, and crosslinked polyethylene. The plastic cable has a simple structure, convenient manufacturing and processing, light weight, convenient laying and installation, and is not limited by the installation drop. Therefore, it is widely used as a medium and low voltage cable, and has a tendency to replace the viscous oil-impregnated paper cable. The biggest drawback is the presence of dendrite breakdown, which limits its use at higher voltages.
3, rubber insulation power cable The insulation layer is rubber plus various compounding agents. After thorough mixing, it is extruded on the conductive wire core and is vulcanized by heating. It is soft and flexible, suitable for occasions with frequent movement and small bending radius.
Commonly used as insulating rubber compound is natural rubber-styrene-butadiene rubber mixture, ethylene-propylene rubber, butyl rubber and the like.
By voltage rating
1. Low-voltage cable: It is suitable for fixed power transmission on the transmission and distribution lines with AC 50Hz and rated voltage of 3kv and below.
2, medium and low voltage cable: (generally refers to 35KV and below): PVC insulated cable, polyethylene insulated cable, XLPE insulated cable.
3, high-voltage cable: (generally 110KV and above): polyethylene cable and XLPE insulated cable.
4, ultra high voltage cable: (275 ~ 800 kV).
5, UHV cable: (1000 kV and above).