Protection system and method for high voltage direct current transmission system
CA 1061861 A · Owner: Hitachi, Ltd. · Inventors: Watanabe, Atsumi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure One of two converters connected by a direct current transmission line is made to operate as a rectifier and the other is made to operate as an inverter under normal operation. When a fault occurs on the transmission line and is detected two of the series connected thyristor arms in one of the converters are made to operate as a bypass pair while the other converter is made to operate as a rectifier controlled by a constant current control means with a suitable reference. This enables the fault to be cleared without stopping current flow in the line.
Read the whole patent
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 September 4, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 4, 1996.
- 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.