Thury direct current transmission system

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DC motors in a Thury system. The insulators under the base plate are clearly visible. (Saint-Maurice – Lausanne transmission line)
DC generator with insulated couplings for the Thury system at the Biberist paper mill

The DC transmission after the system Thury was the Swiss engineer René Thury developed method for the transmission of electrical energy with dc over longer distances. The system used from the 1890s to the 1930s is regarded as the forerunner of high-voltage direct current transmission (HVDC). It is also sometimes referred to as a DC series system .

history

Despite the success of high-voltage transmission with alternating current , which began with three-phase transmission from Lauffen to Frankfurt , the development of transmission of direct current continued.

The first attempts were made by René Thury in Isoverde in 1898, where the Società Anonima dell'acquedotto De Ferrari Galliera was looking for a way to transfer excess energy from a hydroelectric power station to Genoa . A year later, Italy's first power plant, the Galvani power plant , went into operation and transported the electricity over a 14.4 km long line to the San Quirico district of Genoa. The same operator built two more power plants, each with its own transmission line. The one from the Volta power station was 46.2 km long and extended to the center of Genoa, while that of the Pacinotti power station was 32.7 km long and extended to the train station in Sampierdarena .

Further systems based on the Thury system were built in Switzerland in the Jura for the energy supply of La Chaux-de-Fonds and Le Locle and in Valais for the energy supply of Lausanne , in France for the Lyon tram , England, Hungary, Russia and Spain.

The advantages of the Thury system over AC transmission were the lower line losses and the simpler control of the system, so that the speed of the motors could be kept constant. Furthermore, at the beginning of AC technology, there were no motors available that could start up against a load.

technology

Scheme of a Thury system with an output of 1.2 MW

The Thury system consisted of several electric generators and electric motors connected in series , which were connected with a ring line . The electrical current in the ring line was kept constant at a value of around 100  A , while the electrical voltage was adapted to the power requirement and could be up to 12  kV .

Each generator and engine had a bypass switch that was used to shut down the machine without breaking the loop when it was not needed. If a generator was to be put into operation, it was first started up until the electrical current it generated was the same as that in the ring line, and only then was the bypass switch opened. Motors were connected to the network with no load and then accelerated to the desired speed.

The insulation in the Thury system was a challenge because every generator and every motor in the system had to be set up isolated from earth potential . This required insulated foundations for the machines as well as insulated couplings to the turbines and the working machines . The foundations were insulated with asphalt , the base plates of the devices stood on oil insulators .

See also

Web links

Commons : direct current transmission system Thury  - collection of pictures, videos and audio files

Individual evidence

  1. ↑ JL La Cour: Construction, calculation and method of operation . Springer-Verlag, 1927, ISBN 978-3-642-48556-5 , p. 571 ( limited preview in Google Book search).
  2. ↑ Maria Pia Turbi: Le Centrali Idroelecttriche degli Acquedotti di Genova 1883-2008 . June 13, 2009, p. 9 ( cai.it [PDF]).
  3. ↑ a b E. Bossard, Ch. Kunz, E. Baumann: Report on an excursion of the 3rd and 4th annual courses of the mechanical-technical department at the Federal. Polytechnic . 1900, p. 110–112 , doi : 10.5169 / SEALS-21960 (description of the La-Chaux-de-Fonds facility).
  4. ↑ E. Mattern: The utilization of water power: Technical and economic basics . W. Engelmann, 1908, p. 325 ( archive.org ).
  5. ↑ G. Cauderay: Les installations électriques de la ville de Lausanne . 1922, p. 61, 63 , doi : 10.5169 / SEALS-37395 .
  6. ^ A. Rey: Transport d'énergie Moutiers-Lyon par courant continu à 50,000 volts . In: La Houille Blanche . No. October 10 , 1908, ISSN  0018-6368 , p. 229-235 , doi : 10.1051 / lhb / 1908068 .
  7. ↑ A. Denzler: The electrical power transmission of the paper mill Biberist . 1893, p. 73 , col. Left , doi : 10.5169 / SEALS-18175 .
  8. ↑ a b c Rodrigo Teixeira Pinto: Multi-Terminal DC Networks . System integration, dynamics and control. CPI Koninklijke Wöhrmann, Zutphen 2013, ISBN 978-3-659-48663-0 , p. 16 ff .