500 kV power transmission line “Kavkasion” is a unique engineering structure, which is of great importance for the country, its energy supply and security. It crosses Khida and Nakhari passes from Engurhesi through the valleys of Enguri, Nakra, Kodori, Klich and Kuban rivers, crosses the territories of the Karachay-Cherkessia and Adygea republics and enters the Krasnodar region at the Centralnaya substation.

The length of the power transmission line is 405 km and includes 991 masts. The length of the transmission line in the territory of Georgia from “Engurhesi” to Nakhari Pass is 105 km (236 masts). It was commissioned in 1984. In the Kodori valley, it passes to the main ridge of the Caucasus. Due to the difficult terrain of the track, its operation and repair is very difficult, especially in winter conditions. The emergency shutdown of the power plant leads to the deterioration of the stability of the Georgian energy system and the quality of electricity. So far, the 500 kV EGK “Kavkasion” represents an alternative, the only power transmission line, through which it is possible to export the surplus electricity produced at the hydroelectric power stations of Georgia to Russia in the summer, and to fill the deficit from Russia in the winter. It is also used as a transit transmission line for the exchange of electricity in other neighboring countries of Georgia.

Keeping “Kavkasion” in the open state is one of the priority directions of the company’s activity. With the transmission line, it is possible to work in parallel mode with the Russian power system and exchange 700 MW of power.

The wires and masts of the high-voltage power line passing through the harshest climatic and most difficult terrain conditions on the main ridge of the Caucasus were seriously damaged every winter due to freezing or avalanches and represented a significant problem for the energy system. It was almost impossible to stop an avalanche from a height of two and three thousand meters with artificial barriers. There were cases when the so-called “Caucasion” pylons passing through the Nakhari pass, in the same area, were toppled several times during the year by an avalanche. It was virtually impossible to find a safer place to place the masts in this area.

As a result of the above, a decision was made to hang the cables on ropes stretched between the mountains instead of masts in avalanche-prone areas, which, according to the difficulty, in the mountains, at an altitude of 2500 meters, carrying equipment and materials, drilling the rock on the steep side, fastening the ropes and stretching the cables was unprecedented and did not exist in Georgia. analogue. With the selfless work of the company’s specialists Shota Maisuradze, Yuri Nadiradze and others, in the most difficult section, wires were hung on ropes instead of a mast, thus avoiding the problem caused by avalanches and freezing of “Kavkasion” on the section passing through the Kodori valley.

As mentioned above, the so-called “Caucasus” passes through a difficult relief and meteorological climate area. Emergency shut-downs of EKG are mainly caused by atmospheric discharges. The situation is complicated by the fact that the so-called “Caucasion” is not equipped with modern fast-acting protections, single-phase and three-phase automatic reconnection devices. This ensured the sustainability of the parallel operation of the energy systems of Georgia and Russia, as well as the reliability of the units of the Engur HPP. Statistics of emergency shutdowns of “Kavkasion” power plant show that more than 90% of power outages are transient single-phase short-circuits, and if the above-mentioned protection and automatic devices were present on the line, the shutdown of all three phases of the power plant and violation of the parallel operation mode would have been avoided.

In connection with the protections to be implemented at Kavkasion power plant, JSC “Sakrusenergo” received an order from the Ministry of Economy and Sustainable Development of Georgia to equip “General Electric” power plant with production protection systems. In order to ensure the aforementioned, it was necessary to conduct studies using the microprocessor terminal “Multiline L90” to determine the possibilities of implementing relay protection on the so-called “Caucasus”, for which an agreement was signed with the Russian Scientific Research Institute of Relay Construction ОАО “ВНИИР”.

“ВНИИР” presented a report, based on the conclusion of which the works related to “General Electric” on the supply of fast-acting relay protection systems devices, including damage detection devices, their installation and assembly works, training of personnel and their on testing. Fast-acting relay protection systems will be installed on “Kavkasion” in substations “Zvari-500” and “Centralnaya”.

The section of 500 kV Egkh “Kavkasion” passing through the territory of Georgia is served by the Tsalenjikh operation-repair area of ​​JSC “Sakrusenergo”, and the Karachay branch of JSC “Sakrusenergo” on the territory of Russia, which is divided into Maikop and Karachaevsky operation-repair areas.

It should be noted that with the onset of winter another meteorologistAlong with water problems, one of the main dangers of emergency shutdown of the power line is icing. The layer of ice that forms on the power line wires and protective wire at this time exceeds their own weight several times. At this time, as a rule, there is a violation of the gauge and an emergency shutdown of the engine. It is easy to break them, which is why the power line can be out of order for a long time. Despite the fact that Georgia is not an intensive icing zone, isolated cases were recorded at 500 kV power stations “Imeret” and “Kartli-1”, which were followed by emergency shutdowns. In the case of “Imereti” Egkh, the ice caps are mostly found at the Rion river crossing of Egkh, and in the case of “Kartli-1” – near Tbilisi, near the village of Norio. Icing is the main problem in the sections of the so-called “Caucasus” passing through the Kodori Gorge and the territory of Russia, where ice melting devices were previously implemented, which failed over time. To date, with the funding of the company, a deicing point was built and put into operation on the 500 kV substation “Kavkasion” in the Zelenchuk district of the Republic of Karachay-Cherkessia, on the territory of Russia. Melting arrangement