The role of shielding layer in low-voltage power cables

Low voltage power cable products are now used in various ethnic industries, national defense construction, or heavy engineering construction, and are the basic guarantee for the normal operation of modern economy and society. At present, China's wire and cable industry economy generally maintains a stable growth trend, with an increase in export plans.

With the rapid growth of China's economy and the acceleration of industrialization and urbanization, the cable industry of power cable manufacturers and low-voltage power cable manufacturers in China has also developed rapidly. The satisfaction rate of product varieties from power cable manufacturers and low-voltage power cable manufacturers in the domestic market has reached over 95%, and their output value ranks first abroad.

However, the current cable industry structure in our country is severely unbalanced. The supply of BV wires, ordinary wires, and cables is in short supply, while the supply of high-end products is in short supply. Currently, there is insufficient research investment and relatively weak innovation capability in the cable industry. Improving quality will be the main direction for the future low-voltage power cable industry. The shielding layer of low-voltage power cables is a component that prevents the isolation of electromagnetic fields in cable products from external electromagnetic fields.

The resistivity of semiconductor shielding layer is very low, usually divided into conductor shielding layer and insulation shielding layer. The conductor shielding layer covers the conductor, ensuring uniform lubrication of the conductor surface, eliminating the impact of open circuit grounding at the interface between the conductor and the insulation layer on electrical performance, and avoiding partial discharge layers between the conductor and the insulation layer. The insulation shielding layer is wrapped around the insulation surface, in good contact with the shielding insulation layer, and the grounding potential is the same as that of the metal shielding layer. Low voltage power cables eliminate the influence of the open space between the insulation layer and the grounding metal shielding layer (metal sheath) on electrical performance. Low voltage power cables can avoid partial discharge between the insulation layer and the metal shielding layer.

Another type of shielding layer is metal shielding, which is typically made of copper tape and copper wire. As the weaving density and number of layers increase, the shielding effect of low-voltage power cables is enhanced to prevent the magnetic field of current from affecting other components. The commonly used cable shielding layer for Yanggu power cables is usually metal shielding, which is low-cost, effective, and can meet the requirements of most customers.