Power Transmission Systems

Without power lines unthinkabletechnocratic landscape. With this web of humanity, the whole world is covered. The transmission line is one of the elements of electrical systems that transmits energy through a current. By the way of transportation,

cable and overhead power lines.The first are hidden from human eyes, the latter we see daily, leaving the house. In the conditions of dynamically developing civil and industrial construction, the number of power transmission line systems is increasing every year. The requirements to them with regard to capacity and safety are also increasing, as the loads on intersystem components are increasing. The transmission lines are also used to transmit information using high-frequency signals. In the territory of the former USSR, 60 HF and FOC channels are used.

Строительство линий электропередач – сложнейшая engineering problem, which includes the following processes: design, installation, commissioning and maintenance. LEPs are distinguished by the nature of the current: constants and variables. By appointment: distribution,

trunk, ultra-long (as a rule,high-voltage power lines) and consumer (below 20 kV). By voltage: low, medium, high, ultra-high and ultra-high. The highest voltage transmission line is the Ekibastuz-Kokchetav line (1150 kV). According to the mode of operation of neutrals: isolated, compensated, effectively grounded, deafly earthed. By operating modes of power lines: normal, emergency or installation.

The first experiment on the formation of power lines was carried out in the XIX century. Russian engineer Fedor Pirotsky in 1874 used rails of iron

roads to transfer current to a distance.On one rail the current went in one direction, on the second - it came back. The experiment had a positive result, and for several years a car wandered along the route. But several pedestrians received electric shocks, and the project was closed. By the way, the experiment was not lost in vain - today's metro operates exactly on this principle.

In those years, scientists around the world were busydevelopment of various methods of current transmission over long distances. The most effective system was proposed and created by the Russian inventor Mikhail Dolivo-Dobrovolsky. In 1891, under his leadership, the first three-phase current line was built at a distance of 170 kilometers. The energy losses decreased by a quarter. At the International Electrotechnical Exhibition in Germany, scientists around the world recognized that the problem was solved. In St. Petersburg, the Electrotechnical Institute was opened, which developed a system of electrification of Russia and trained specialists.

Initially, Russia did not have its own industrialbases for electrification of the country - the wires were brought from abroad, and the supports were made from improvised material - wood. During the First World War, the revolution and civil war, the construction of power lines was suspended. And since 1923 the students of Mikhail Dolivo-Dobrovolsky, who stayed in Russia, continued the work of their teacher.