DC transmission between Kriegstetten and Solothurn

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The DC transmission between Kriegstetten and Solothurn was put into operation on December 18, 1886. It is considered to be one of the first commercial systems for the transmission of electrical energy in Europe. The eight kilometer long overhead line was operated with a direct voltage of 2000  V and was used to supply the Müller-Haiber screw factory from the Kriegstetten power plant in the Swiss canton of Solothurn .

history

Bevel gear over the Girard turbine in the power plant
The two direct current generators in the power plant
Concession plan with the course of the transmission line

The screw factory founded in 1876 in the old Schanzmühle was expanded several times, so that the drive power provided by a mill wheel was soon no longer sufficient. A steam engine was out of the question for the energy supply because its uneven speed would have endangered the quality of the screws made for the watch industry. In 1886, the entrepreneurs therefore commissioned Maschinenfabrik Oerlikon (MFO) to set up a power plant in an empty paper factory on the Ösch in Kriegstetten and to transmit the electricity to the factory in Solothurn via an overhead line.

The execution of the system was supervised by the then chief engineer Charles EL Brown , who later, together with Walter Boveri, founded the electrical engineering group Brown, Boveri & Cie. founded. Extensive measurements of its efficiency were carried out on the system, which were published in various specialist publications and were intended to convince skeptics of electrical energy transmission of its high efficiency . For this reason, it was also important to only provide evidence using mechanical measured variables. The system was regarded as a reference for the technical abilities of the MFO to build such systems, which later enabled her to work on the three-phase transmission between Lauffen and Frankfurt .

The Kriegstetten – Solothurn transmission line was one of the first systems of this type that was not built for an experiment or an exhibition, but had a commercial use and was in permanent operation until 1908. It was not the oldest system of its kind, because in 1884 electricity was transferred from the Taubenloch Gorge to a clock factory 1.2 km away and the Thorenberg power plant near Lucerne started operation just a few months before the Kriegstetten – Solothurn plant. However, the aforementioned systems did not reach the length of eight kilometers.

A generator and a motor have been preserved from the system, which are owned by the Deutsches Museum in Munich . The building of the power plant has been demolished, in its place there is an information board.

technology

A Girard turbine supplied by Josef Meyer drove two generators that worked at 700  revolutions per minute and delivered around 18 kW at a terminal voltage of 1 kV to 1.25 kV. The direct current generators were connected in series and supplied a three-wire system that was operated with 2 kV to 2.5 kV between the two outer conductors . In the factory, two DC motors, identical in construction to the generators, were installed, which - also connected in series - drove transmissions for the belt-driven lathes .

The overhead line between the power station and the factory was laid on poles 40 m apart. The three conductors used copper wires with a diameter of 6 mm and attached to oil insulators . A silicon bronze ladder was used to cross the Aare , where the distance between the poles was 120 m . At the beginning and end of the line, surge arresters were installed as lightning protection. In the factory there was also a main oil switch in front of each engine . In the event of a generator failure, one of the two outer conductors could be interconnected with the neutral conductor , so that the overall resistance of the line could be reduced.

See also

literature

  • Walter Moser: On the history of public lighting in the city of Solothurn from the first half of the 19th to the first quarter of the 20th century . In: Historischer Verein des Kanton Solothurn (Hrsg.): Yearbook for Solothurn history . tape 68 , 1995, pp. 200–204 , doi : 10.5169 / SEALS-325152 ( e-periodica.ch ).
  • CEL Brown: The electrical power transmission from Kriegstetten-Solothurn . In: Schweizerische Bauzeitung . tape 8 , no. 26 , 1886, p. 156–158 , doi : 10.5169 / SEALS-13714 ( e-periodica.ch ).

Web links

Commons : Kraftwerk Kriegstetten  - Collection of images, videos and audio files

Individual evidence

  1. ^ CEL Brown, page 158, 1st column
  2. ↑ Gugerli, David: Redeströme: for the electrification of Switzerland; 1880-1914 . Chronos, Zurich 1996, ISBN 3-905311-91-7 , p. 65 .
  3. ^ A b C. EL Brown, page 157, 1st column
  4. ↑ Anonymous: Electrical power transmission Kriegstetten-Solothurn. In: Polytechnisches Journal . tape 268 , 1888, pp. 169–171 ( hu-berlin.de ).
  5. ↑ Marco Jaggi: When a Solothurn power line caused a sensation across Europe. SRF, May 23, 2016 (caption for the 4th image in the gallery.).;
  6. ^ Christoph Zürcher: Fritz Blösch. In: Historical Lexicon of Switzerland , accessed on November 20, 2019 .
  7. ↑ Thury, René . Obituary. In: Schweizerische Bauzeitung . tape 112 , no. 5 , July 30, 1938, p. 57 , col. left .