A transformer boosts the power supplied by the generator and connects it to the transmission line using control devices like a circuit breaker.
There are two types of transmission lines:
- Overhead lines and
- Cable lines.
Overhead Transmission Lines
Overhead transmission lines are power transmission lines that are placed on the ground and attached with transmission insulators to the pole towers standing on the ground to convey electrical energy.
Overhead wires are a popular technique of power transmission.
Cable Line
Cable line is an electrical signal transmission system made up of power transmission cables and associated equipment including cable lugs, connectors and wire terminals.
Path Selection
Path selection and surveying are critical to the overall line design.
The scheme’s rationality is crucial in terms of economic and technical metrics, as well as line construction and operation.
To fairly cut the length of the route, reduce the route’s investment while ensuring safety, reliability, and convenience.
Survey Work
In the survey work, the economic rationality of pole positions & the feasibility of building critical pole positions (such as corners, junctions, and specific areas where pole towers must be built, etc.) are considered.
The repeated measurement and comparison must be carried out in some special parts so that the position of the pole & tower can avoid the traffic challenging area as much as possible, resulting in better construction conditions for the assembly of towers & tight lines.
Tower Type Selection
Different tower types differ in terms of cost, site use, construction, transportation, and operational safety.
The tower project costs approximately 30% to 40% of the overall project budget. The objective is to make a reasonable choice of tower type.
For lines with numerous circuits of the same tower and built along the intended route, the steel tube tower with reduced floor space is commonly utilised for the tower.
However, if steel towers are used for huge corner towers, the top of the pole can easily distort due to structural reasons, and the foundation construction cost would be twice that of an angle steel tower.
So the straight tower employs a steel pipe tower, whereas the corner tower uses an angle steel tower, which is more sensible.
Foundation Design
The tower foundation is a significant component of the transmission line structure, as are its cost, construction time, and labour requirements.
The construction period accounts for around half of the total construction time, the transportation capacity accounts for 60% of the total project, and the cost accounts for 20% to 35% of the total project.
The tower foundation’s selection, design, and construction have a direct impact on the line project.