What are Overhead Lines and Cables?
Overhead cables refer to wires erected in the air through iron towers and cement pole towers, generally bare wires. A cable is made of one or more conductors insulated from each other and overlaid with insulating protection, and is a wire that transmits electricity or information from one place to another.
The Difference of Bare Conductors And Cable
Overhead line: uninsulated, bare metal conductor, erected in the air to be fixed on the tower, with air as insulation. Main advantage: low cost. The disadvantage is that it occupies a lot of land resources (line corridors). And it affects the appearance of the city.
Cable: Insulating medium is used to isolate the metal conductor from the outside world, and it is laid on the ground or underground. The main advantage is that it is more convenient to lay, occupies less land resources, and does not affect the appearance of the city. The disadvantage is that the cost is too high.
In terms of safety, the industry currently believes that due to factors such as materials and manufacturing processes, overhead lines have excellent safety and low failure rates.
What are the Parts of Transmission Line?
Everyone must be familiar with power transmission lines. In urban steel forests and on rural roads, we often see many power transmission towers and utility poles. In fact, their professional name is overhead power lines. At present, overhead lines are mostly used for high-voltage transmission and rural distribution lines.
Overhead lines consist of conductors, insulators, fittings, towers and their foundations, lightning conductors and grounding devices.
Conductor: Conducts current, it is the basic part of the line.
Insulator: When the wire conducts current, it keeps the three phases insulated from each other and from the ground.
Pole tower: It is to erect the wire so that there is a certain distance between the wire and the ground and its three phases.
Hardware: metal accessories that connect wires and insulators, etc., and install them on the tower.
Lightning protection wire: prevent lightning from hitting the wire directly.
Grounding device: connect the lightning protection wire and the soil, and introduce the lightning current into the ground.
What are the Parts of Transmission Line?
Everyone must be familiar with power transmission lines. In urban steel forests and on rural roads, we often see many power transmission towers and utility poles. In fact, their professional name is overhead power lines. At present, overhead lines are mostly used for high-voltage transmission and rural distribution lines.
Overhead lines consist of conductors, insulators, fittings, towers and their foundations, lightning conductors and grounding devices.
Conductor: Conducts current, it is the basic part of the line.
Insulator: When the wire conducts current, it keeps the three phases insulated from each other and from the ground.
Pole tower: It is to erect the wire so that there is a certain distance between the wire and the ground and its three phases.
Hardware: metal accessories that connect wires and insulators, etc., and install them on the tower.
Lightning protection wire: prevent lightning from hitting the wire directly.
Grounding device: connect the lightning protection wire and the soil, and introduce the lightning current into the ground.
Introduction to Overhead Transmission Lines
The overhead line is composed of wires, overhead ground wires, insulator strings, towers, grounding devices and other parts. The conductors of overhead transmission lines are all at high potential. In order to reduce the power loss and electromagnetic interference caused by corona discharge, the wire should also have a large radius of curvature. Ultra-high voltage transmission lines, due to large transmission capacity and high working voltage, mostly use split conductors into one-phase conductors.