The concept of power cables

——The insulated power supply that can transmit large-capacity electric energy safely and reliably for a long time is called “power cable”.

Power cables are cables whose conductors are covered with high-quality insulating materials and have various protective layers. Its main function is the same as that of overhead wires, to transmit and distribute large-capacity electrical energy in the power system. The difference from overhead lines is that power cables can be laid in various environments, safe and concealed, and not disturbed by external climate changes; and they can be less maintained and durable (generally more than 40 years).

However, the structure of power cables is relatively complex, with many manufacturing processes, and the product price is dozens of times higher than that of overhead wires; therefore, it is generally used in occasions where overhead lines are not suitable, such as power transmission and distribution lines in cities and industrial and mining enterprises. In the main power lines of the factory; as well as across the Jianghe railway station, through the underground tunnels, etc.

In fact, power lines are composed of overhead conductors and power cables. Overhead conductors focus on the transmission, transformation and distribution parts of power generation, while power cables focus on power distribution and power consumption. Therefore, the production of medium and low voltage power cables The amount accounts for more than 98%.

With the rapid improvement of the economic level, the proportion of power cables in the power system is increasing. For example, the medium and low voltage overhead lines in the city center will gradually be changed to concealed cable lines, and the suburban and central towns will use overhead insulated cables.