The Moscow–Kashira HVDC transmission system was an early

high-voltage direct current A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curre ...

(HVDC) connection between the town of

Kashira Kashira (russian: Каши́ра) is a town and the administrative center of Kashirsky District in Moscow Oblast, Russia, located on the Oka River south of Moscow. Population: History It was first mentioned in 1356 as the village of Koshira ...

and the city of

Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million ...

in Russia, where the terminal was at . The system was built using

mercury-arc valve A mercury-arc valve or mercury-vapor rectifier or (UK) mercury-arc rectifier is a type of electrical rectifier used for converting high-voltage or high- current alternating current (AC) into direct current (DC). It is a type of cold cathode gas-f ...

s and other equipment removed from the

Elbe Project The Elbe Project (german: Elbe-Projekt) was the name of the first commercial, static high voltage direct current transmission system constructed in the world. The scheme was based on mercury arc valves. Experimental installations between Wettin ...

Berlin Berlin is Capital of Germany, the capital and largest city of Germany, both by area and List of cities in Germany by population, by population. Its more than 3.85 million inhabitants make it the European Union's List of cities in the European U ...

at the end of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. Although primarily experimental in nature, the system was the first true static, electronic, high-voltage DC scheme to enter service. Earlier DC transmission schemes had either used electromechanical converters based on the Thury system, such as the Lyon–Moutiers DC transmission scheme or had been at only medium voltage, such as the 12 kV frequency converter scheme at

Mechanicville, New York Mechanicville is a city in Saratoga County, New York, United States. The population was 5,196 at the time of the 2010 census. It is the smallest city by area in the state. The name is derived from the occupations of early residents. The city is lo ...

in the United States. The scheme had a nominal power rating of 30 MW and was operated at different times as a bipole at ±100 kV or a monopole, with earth return, at 200 kV. For most of the transmission distance of 125 km, the transmission conductor was underground cable but some sections were converted to

overhead line An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipm ...

. The route of the line was between Kashira and Moscow parallel to the existing 110 kV overhead AC line. Initial operating experience was gained using three series-connected, single

anode An anode is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device. A common mnemoni ...

mercury arc valves in each converter arm, but by 1959 experience had been gained with operating with either one or two mercury arc valves in series per arm.Nekrasov, A.M., Posse, A.V., Work done in the Soviet Union on High-Voltage Long-Distance DC power transmission, A.I.E.E. Transactions, Vol. 78, part 3A, August 1959, pp515–521. The experience gained with multiple valves in series in each arm was not wholly successful and the little available literature suggests that the reliability of the scheme was poor. This may have been because the valves, unlike those being developed in Sweden by Dr

Uno Lamm August Uno Lamm (May 22, 1904 – June 1, 1989) was a Swedish electrical engineer and inventor. He was sometimes called "The Father of High Voltage Direct Current" power transmission. During his career, Lamm obtained 150 patents. In 1980 the ...

, lacked the external anode voltage divider networks which were found necessary to obtain reliable operation at high voltage. Nevertheless the scheme provided valuable experience for designing the much larger ±400 kV Volgograd–Donbass project which was completed in 1965 using mercury arc valves of entirely Soviet design. In 1969 the first thyristor valve built in the Soviet Union was installed in the converte

The scheme is however today not in use any more, whereby it is unknown when it was shut down. It is unknown, if the cable is still in place and if the converter hall in Kashira is still standing.

References

Electric power transmission Electric power infrastructure in Russia HVDC transmission lines Energy in the Soviet Union {{powerline-stub

See also

References