Composition of overhead lines: conductors, insulators, fittings, towers and their foundations, lightning conductors and grounding devices, etc.
Wire: Conducts current, which is the fundamental part of a circuit.
Insulator: When conducting current in a wire, maintain insulation between the three phases and ground.
Tower: It is used to erect conductors so that there is a certain distance between the conductor and the ground and its three phases.
Hardware: A metal accessory used to connect wires, insulators, etc., and install them on the tower.
Lightning protection wire: to prevent direct lightning strikes on the conductor.
Grounding device: Connect the lightning wire to the soil and introduce lightning current underground.
Tips: Actually, besides the overhead power lines we can see in our daily lives, there are also many underground cables. The cable occupies a small area, has reliable power transmission, and strong anti-interference ability, but it is difficult for ordinary people to see it once.
2. How to define high voltage, ultra-high voltage, ultra-high voltage? Why are there so many voltage levels?
In the early stages of the development of the power industry, power plants were generally built near power users. With the expansion of power production scale and load center scale, the transmission capacity is also increasing, and the transmission voltage is getting higher and higher.
Globally, the voltage levels of transmission networks are generally divided into high voltage, ultra-high voltage. In the AC voltage level, high voltage refers to 110 kV and 220 kV; Ultra high voltage refers to 330 kV, 500 kV, and 750 kV; Ultra high voltage refers to 1000 kV. In the DC voltage level, ultra-high voltage refers to ± 500 kV and ± 660 kV, while ultra-high voltage refers to ± 800 kV. The 1000 kV AC voltage has become the national standard nominal voltage.
3. How to see through the voltage level of the circuit at a glance?
For ordinary non electrical professionals, how can different voltage levels be distinguished with the naked eye?
The more insulators there are, the higher the voltage level.
In areas with an altitude of 1000 meters or below, the minimum number of insulator pieces required for operating overvoltage and lightning overvoltage under different voltage levels for suspension insulator strings is: 7 pieces at 110 kV, 9 pieces at 132 kV, 13 pieces at 220 kV, 15 pieces at 232 kV, 17 pieces at 330 kV, 25 pieces at 500 kV, and 32 pieces at 750 kV.
High voltage level lines require a larger safety distance and must be erected high, and only iron towers can be capable of supporting lines weighing tens of tons.
In addition, the higher the voltage level, the greater the vertical distance between the upper and lower wires, and the higher the distance between the line and the ground.
Simple, direct, and effective: Look at the pole tower. The sign above the tower indicates the voltage level of the line. Generally, 1 starts at 110 kV, 2 starts at 220 kV, and so on. 5 starts at 500 kV.
4. Why are transmission towers of different shapes often seen?
The type of tower is related to many factors, such as transmission voltage, number of circuits, types of conductors and ground wires, and installation methods. In the eyes of ordinary people, the most intuitive difference is the appearance of the tower.
According to the global transmission tower design specifications, transmission towers worldwide can be mainly divided into wine glass towers, cat head towers, stem shaped towers, drum shaped towers, etc. according to tower types.
The wine glass tower is usually used for power transmission lines with voltage levels of 110 kV and above, especially suitable for heavy ice or thunderstorm areas.
Cat head type towers are also commonly used for power transmission lines with voltage levels of 110 kV and above. Its advantage lies in its ability to effectively save on route corridors.
The stem shaped iron tower is mainly used as a tension tower and corner tower due to its clear and direct force situation, economy and practicality. It is a commonly used tower type for power transmission lines with voltage levels of 220 kV and above.
The double circuit drum tower is a commonly used tower type for double circuit iron towers, and its wires are arranged in a drum shape, hence its name. Suitable for areas with heavy icing, it can avoid wire collision and flashover accidents during wire detachment and jumping.
5. With the increase in global energy demand, the power industry has also become a very important industry driving global economic development. However, in the process of development, we should also see that relevant measures need to be taken and continuously improved in the construction of global power facilities. Transmission towers are an important component of transmission lines, So the quality of its design also directly affects the normal operation of the transmission line. Hengfengyou Tower - With 30 years of experience in global power tower production and manufacturing, it has been successfully sold to over 50 countries worldwide, including Kazakhstan, Uzbekistan, Iraq, Kuwait, the United Arab Emirates, Oman, Qatar, Tanzania, Zimbabwe, South Africa, Uganda, Rwanda, Ethiopia, Ghana, Bangladesh, and more. For more information on power towers, please visit the official website of Hengfengyou http://www.hengfengyou.com ；
