What is a Transmission Line Corridor? The Concept of Transmission Line Corridors

The transmission line corridor refers to the strip-shaped area under the line that extends to both sides with a specified width along the side conductor of the high-voltage overhead power line. In this area, the public is allowed to enter or engage in essential agricultural and other restricted production activities.

1. The concept of transmission line corridors

The transmission line corridor refers to the strip-shaped area under the line that extends to both sides with a specified width along the side conductor of the high-voltage overhead power line. In this area, the public is allowed to enter or engage in essential agricultural and other restricted production activities.

2. Transmission lines in transmission line corridors

The transmission line is realized by using a transformer to boost the electric energy generated by the generator, and then connecting it to the transmission line through control equipment such as a circuit breaker. Structural forms, transmission lines are divided into overhead transmission lines and cable lines.

3. Overhead transmission lines in transmission line corridors

The overhead transmission line is composed of line towers, wires, insulators, line fittings, guy wires, tower foundations, grounding devices, etc., and is erected above the ground. According to the nature of the transmission current, power transmission is divided into AC transmission and DC transmission. In the 1880s, DC transmission was first successfully realized. However, because the voltage of DC transmission was difficult to continue to increase under the technical conditions at that time, the transmission capacity and benefits were limited. At the end of the 19th century, DC transmission was gradually replaced by AC transmission. The success of AC transmission ushered in a new era of electrified society in the 20th century.

4. Line corridors for transmission line corridors

Line corridors, land areas and spatial areas occupied by the paths of overhead transmission lines.

Overhead transmission lines install conductors on towers for power transmission. The tower foundation needs to occupy land. In order to ensure the insulation strength of the line and avoid the danger of electric shock to people, ground buildings and other objects, and to prevent the electrostatic field from causing physiological and ecological hazards to the wires and nearby people, it is necessary to maintain a necessary clear space around the wires under high voltage. . High-voltage overhead transmission lines will generate an induced electrostatic field on the surface of the earth. In order to weaken the intensity of this electrostatic induced electric field to the extent that it will not endanger personal safety, the conductor must be suspended at the proper height. When the line is running normally, especially when a short-circuit fault occurs, the magnetic field of the conductor current will generate electromagnetic induction to the adjacent power or telecommunication system, and it is necessary to keep a sufficient distance between the conductor and it to reduce this electromagnetic induction. The above requirements constitute the conditions that should be considered when determining the route corridor.

As the voltage level of transmission lines increases, the extent of line corridors expands significantly. For example, for a single-circuit 500 kV ultra-high voltage transmission line, the height of the tower is generally 30 meters, and the width of the line corridor is about 45 meters. Therefore, occupying the line corridor becomes one of the difficulties in the development of overhead transmission lines. When the overhead line needs to cross buildings and densely populated areas, mountains, forests, rivers, and areas such as landscaping, the problem of line corridors is more prominent.