For high-voltage cables, we can reach the main line of electricity wires, cables in the underground pipe network.
Components of the high-voltage cable from the inside to the outside include: conductor, insulation, inner sheath, filler (armor), and external insulation. Of course, armored high-voltage cables are mainly used for grounding, which can resist the high-strength pressing on the ground and prevent other external damage.
As a type of high-voltage cable, its purpose is to transmit power in the range of ten kilovolts to thirty-five kilovolts, and the application of trunk transmission is relatively high. The considerations for the selection of high-voltage cables are quite complex because of the variety of types. As a cable itself, high-voltage cables can be classified into aluminum high voltage cables, or copper high voltage cables, depending on the material. For areas with complex environmental conditions and special requirements, the use of copper core cables is more reliable in terms of quality and safety. For our construction, cable model selection should refer to the surrounding environment, laying the corresponding means, and the performance of electrical equipment. etc
1. Buried type refers to the direct laying of high-voltage cables in the ground (different according to different geological conditions, generally should be greater than 0.7 meters). The use of underground laying has higher requirements for the protection of the cable itself, and it is suitable for the use of armored power cable with an outer protective layer; for some unstable geological conditions such as swamps, quicksand, steel wire armored power cable can also be selected. (In fact, the armored cable that we talked about is actually a kind of flexible assembly. It is characterized by its rigidity, internal materials and conductors, and the metal sleeve has an insulating layer.)
2. Pipeline refers to the laying of high voltage cables in prefabricated pipes. This laying method can easily cause the cable to overheat, resulting in power loss and capacity reduction, so it is more suitable to use plastic protective sleeve cable or bare armored cable.
3. Tunnel type refers to the laying of high-voltage cables on the bridge or bracket in the cable tunnel. This kind of laying method is mostly used in cities, and has the characteristics of good heat dissipation and easy maintenance. However, it has a higher requirement for the flame retardancy of cables and is suitable for the use of bare armoured cables or flame-retardant plastic protective sleeve cables.
4. Overhead type refers to the laying of high voltage cables through poles (poles). This laying method is suitable for areas with flat terrain and less undulations, such as AAAC, ACSR and other overhead lines. But for high-voltage cables, this method is not common.