High resistance ground fault protection
CA 1311044 C · Owner: Asea Brown Boveri Ab · Inventors: Ljung, Stefan; Bergman, Sten
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A protection device for high resistance ground faults in a power network according to the invention has a fault detection principle which is based on an indirect study of non-harmonic frequency components of the phase currents. When such a fault has occurred, a considerable change of the energy contents of these frequencies arises. This change can be detected by a device according to the invention. If by comparison (4e) between digitized input signals (I') and a harmonic Fourier model (4d) of the same signals, i.e. generation of the residuals of the system, it is found that a difference exists and if the corre-, sponding loss function VN (4f) for a certain time exceeds a lower limit value - …
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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
- Granted December 1, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 1, 2009.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.