Method and device for preventing understabilization of longitudinal differential protection in case of external fault and current transformer saturation
CA 2136341 C · Owner: Wennerlund, Per · Inventors: Wennerlund, Per; Saha, Murari Mohan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and a device for preventing understabilization of longitudinal differential protections in case of external faults and current transformer saturation. The invention comprises an extension of the state of the art with regard to stabilization of longitudinal differential protections in such a way that the values (A1 A2, ... An), (.PHI.1, .PHI.2, ... .PHI.n) obtained via current measurement, (C1, C2 ... Cn) and Fourier filters (4, 5, 6), for determining the function characteristic of the protection under certain conditions as regards current amplitude and current transformer saturation are given corrected values (A1k A2k, ... Ank), (.PHI.1k, .PHI.2k, ... .PHI.nk).
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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 May 7, 1993 and granted November 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 7, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.