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Expired Canadian patentCanada

Method and apparatus for limiting current in a direct voltage network of a power transmission system

CA 2218941 C · Owner: Asplund, Gunnar · Inventors: Asplund, Gunnar

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Abstract From the Canadian patent

Apparatus and method for limiting current in a direct voltage network of a HVDC power distribution system. A direct voltage network is connected to an alternating voltage network through a VSC-converter. At least one parallel connection including a semiconductor switching element is connected in series with the direct voltage network. A surge diverter is connected in parallel with the semiconductor switching element. During a high current condition in the direct voltage network the switching element is switched off interrupting the current flow which is then diverted through the surge diverter which reduces the current flowing in the direct voltage network. By inserting a plurality of …

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed November 12, 1997 and granted April 17, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 12, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 12, 2019.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledNovember 12, 1997
GrantedApril 17, 2001
Term endedNovember 12, 2017
Patent numberCA 2218941 C
Classification (IPC)H02H3/08 +1 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedNov 12, 1997Patent grantedApril 17, 2001Term endedNov 12, 2017

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.