Cable shield
1. Add a shielding layer of semiconducting material on the surface of the conductor, which has the same potential as the shielded conductor and is in good contact with the insulating layer, so as to avoid partial discharge between the conductor and the insulating layer. This layer of shielding is also known as the inner shielding layer. There may also be gaps at the contact between the insulating surface and the sheath. When the cable is bent, the insulating surface of the oil-paper cable is prone to cracks, which are all factors that cause partial discharge.
2. Add a shielding layer of semi-conductive material on the surface of the insulating layer, which has good contact with the shielded insulating layer and is equipotential with the metal sheath, so as to avoid partial discharge between the insulating layer and the sheath.
The shielding layer of the cable In order to evenly conduct the core and insulating the electric field, the medium and high voltage power cables of 6kV and above generally have a conductor shielding layer and an insulating shielding layer, and some low-voltage cables do not have a shielding layer. There are two types of shielding layers: semi-conductive shielding and metal shielding.
