According to voltage level
According to voltage level, it can be divided into medium and low voltage power cables (35 kV and below), high voltage cables (above 110 kV), ultra-high voltage cables (275-800 kV) and ultra-high voltage cables (1000 kV and above). In addition, it can be divided into AC cables and DC cables according to the current system.
According to insulation materials
1. Oil-impregnated paper insulated power cable is a power cable insulated with oil-impregnated paper. It has the longest application history. 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 drip-free impregnated paper insulation, the drop limit problem has been solved, allowing oil-impregnated paper insulated cables to continue to be widely used.
2. Plastic insulated power cable The insulation layer is an extruded plastic power cable. Commonly used plastics are polyvinyl chloride, polyethylene, and cross-linked polyethylene. Plastic cables have a simple structure, are easy to manufacture and process, are light in weight, are easy to lay and install, and are not limited by the laying drop. Therefore, they are widely used as medium and low voltage cables, and there is a trend to replace viscous impregnated oil paper cables. Its biggest disadvantage is the dendrite breakdown phenomenon, which limits its use at higher voltages.
3. Rubber insulated power cable The insulation layer is rubber plus various compounding agents. After being fully mixed, it is extruded on the conductive wire core and vulcanized by heating. It is soft and elastic, suitable for occasions with frequent movement and small bending radius.
Commonly used rubber materials for insulation include natural rubber-styrene-butadiene rubber mixture, ethylene-propylene rubber, butyl rubber, etc.
According to voltage level
1. Low-voltage cable: suitable for fixed laying on AC 50Hz, rated voltage 3kv and below transmission and distribution lines for transmitting electric energy.
2. Medium and low voltage cables: (generally 35kV and below): polyvinyl chloride insulated cables, polyethylene insulated cables, cross-linked polyethylene insulated cables, etc.
3. High-voltage cables: (generally 110kV and above): polyethylene cables and cross-linked polyethylene insulated cables, etc.
4. Ultra-high voltage cables: (275~800kV).
5. Ultra-high voltage cables: (1000kV and above).