High-voltage Overhead Cables VS High-voltage Power Cables
 

1.Overhead transmission lines are composed of line tower, wires, and insulators, and are erected on the ground.

The wires are made of a well-conducting metal, with a sufficiently thick section (to maintain proper flow density) and a large radius of curvature (to reduce corona discharge). EHV transmission uses split wires. Overhead ground wires (also called lightning conductors) are placed above the transmission conductors to protect the wiring from lightning strikes.

Overhead line erection and maintenance are more convenient and the cost is lower. Overhead transmission lines are designed to take into account the effects of various natural conditions such as temperature changes, severe storms, lightning flashes, rain, ice, floods, and wet fog. There must be sufficient ground width and clearance corridors for the overhead transmission lines.

2.Power cable line

Power cables generally consist of wires, insulation layers, and protective layers, with single-, dual-, and triple-core cables.

Underground cable lines are often used in areas where overhead lines are difficult to set up, such as transmissions in cities or in special crossings. At present, the use of cable power transmission, mainly from the perspective of urban landscape and line security. However, fault finding time and maintenance time of the cable line are very long, which has a serious impact on the reliability of the grid operation and the normal power consumption of the user. Therefore, in the construction of power grids, the replacement of overhead lines with cable lines cannot be achieved.