The Moscow–Kashira HVDC transmission system was an early

high-voltage direct current A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages betwe ...

(HVDC) connection between the town of

Kashira Kashira () is a types of inhabited localities in Russia, town and the administrative center of Kashirsky District, Moscow Oblast, Kashirsky District in Moscow Oblast, located on the Oka River south of Moscow. Population: History It was first ...

and the city of

Moscow Moscow is the Capital city, capital and List of cities and towns in Russia by population, largest city of Russia, standing on the Moskva (river), Moskva River in Central Russia. It has a population estimated at over 13 million residents with ...

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 in

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

at the end of

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. 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 5,163 at the 2020 census, a small decrease from 5,196 in 2010. It is the smallest city by area in the state. The name is derived from the occupations of early ...

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 Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...

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, Electric multiple unit, electric multiple units, trolleybuses or trams. The generic term used by the International Union ...

. 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 usually is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, which is usually an electrode of the device through which conventional current leaves the devic ...

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, 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 The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

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

{{DEFAULTSORT:Moscow-Kashira HVDC transmission system Electric power transmission Electric power infrastructure in Russia HVDC transmission lines Energy in the Soviet Union

See also

References