Đường dây trên không được hỗ trợ bởi các phần của tháp truyền tải.
Cột điện được sử dụng cho đường dây có điện thế cao hơn.
Và cột gỗ hoặc bê tông thường được sử dụng cho đường dây có độ căng thấp hơn.
Điều này là do các đường dây có độ căng cao hơn (đường dây căng cao nhất) phải được lắp đặt ở độ cao lớn, vì họ yêu cầu khoảng trống an toàn lớn hơn.
Chỉ có cột điện mới có thể mang được những dây điện nặng hàng chục tấn.
What you see along the road on the suburbs are usually transmission towers.
As for the types of towers, there are cat-head towers, wine-glass towers, gate-shaped towers, V-shaped towers, vân vân.
Voltage on overhead transmission lines
Rated voltage refers to the voltage between any two of the three ABC phases.
The standard domestic voltage of 220 volts is the voltage between any of the three phases to ground.
In reality, the line that transmits electricity to the house is 380 volts.
And the three phases are separated before entering the house.
Ví dụ, each of the three ABC phases is connected to each of the units in a building.
Overhead ground lines
Transmission lines are also divided into direct current and alternating current (DC and AC).
MỘT AC circuit is composed of phases A, B and C.
The top of the transmission tower is the lightning line, also called overhead ground wire.
Lines located in areas with many storms or high voltage have two lightning lines.
Lines with fewer storms or low voltage may use only one lightning line.
Lightning lines are connected to poles to direct the lightning current to the ground.
Overhead transmission lines
Below the lightning lines are the transmission lines.
The number of wires are all multiples of 3. The single-circuit line contains 3 dây điện, the two-circuit line contains 6 dây điện, and the four-circuit line contains 12 dây điện.
In each circuit there are three wires for each of the three phases A, B and C.
The reason why there are several circuits in a tower is mainly due to the consideration of transmission capacity and footprint. This is why the concepts of “line length” Và “circuit length” have also been developed.
For two-circuit lines, the circuit length is twice the line length and so on.
In the case of different voltage levels, the voltage of the upper conductor is higher than that of the lower conductor.
This is because the higher the voltage, the greater the required safety distance to ground.
Lightning lines are well distinguished from transmission lines.
The former is directly on top of the tower, while the latter must be suspended from the tower by insulators.
If there are no insulators, the conductor is shorted directly to the tower.
The insulator is an accessory for overhead wires (alambres aéreos) used to support and secure the conductor.
It can ensure proper distance and insulation between conductors or between conductors and ground.
Insulators should have sufficient electrical insulation strength and moisture resistance.
We hope this article will help you to understand overhead line and electric tower properly.
We provide high quality and low price of various overhead lines and their accessories.
Please contact us if you need them.
