What is a wire and cables?
wire and cables are cable products used to transmit and distribute high-power electricity in the main lines of the power system. They are commonly used in urban underground power grids, power station outgoing lines, internal power supply for industrial and mining enterprises, and underwater transmission lines across rivers and seawater.
The basic structure of wire and cables consists of four parts: core (conductor), insulation layer, shielding layer, and protective layer.
1 、 Wire core: The wire core is conductive and used to transmit electrical energy, making it the main part of power cables.
2、 Insulation layer: The insulation layer can electrically isolate the wire core from the ground and wire cores of different phases, ensuring the transmission of electrical energy, and is an indispensable component of the power cable structure.
3、 Shielding layer: Power cables of 15KV and above generally have a conductor shielding layer and an insulation shielding layer.
4、 Protective layer: The function of the protective layer is to protect the power cable from external impurities and moisture intrusion, as well as to prevent direct damage to the power cable by external forces.
Advantages of power cables:
1、 Small footprint. The various wires hovering in the air are disorganized, which not only affects the visual effect but also occupies a lot of space. However, power cables, due to their small insulation distance between wires, do not need to erect poles, and can be buried in soil, tunnels, or indoor laying, which not only saves space but also does not damage the local scenery.
2、 High reliability of power cables. The protective layer of power cables can not only be waterproof, but also prevent other impurities from corroding the cables, which undoubtedly reduces the impact of climate and surrounding environment on it. Its insulation layer ensures the independence and stability of power transmission between cables.
3、 There is a lot of room for improvement. After continuous optimization, the power capacity and voltage of power cables are increasing, which gradually increases their value in use. The increasing demand for them has also driven their improvement to a certain extent.
4、 Its maintenance work is relatively small. Due to the fact that the power cable laying channel does not need to be exposed, the daily damage to the cable will also be reduced, and its maintenance work will be less than that of ordinary wires.
5、 The distributed capacitance is relatively large. The materials selected as power cable cores have extremely high conductivity, and there are usually multiple cores inside the cable. Compared to overhead lines with the same cross-sectional area, power cables with a unit length have a slightly larger capacitance.
6、 The possibility of electric shock is low. The conductor core of power cables is wrapped with an insulation layer, shielding layer, and protective layer, which can slow down the aging speed of the line and reduce the possibility of damage, resulting in a corresponding reduction in the likelihood of electric shock.
