Control systems for an electric drive
CA 1297149 C · Owner: Hill, Walter A. · Inventors: Hill, Walter A.; Schwalm, Charles L.; Creelman, Gregory S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, A control system for an icebreaker drive has a ship's telegraph for inputting a speed reference signal representing a desired speed at which the electric motors propelling the ship are to run. The motors receive power from a controllable converter which, in turn receives, power from an AC generator or generators driven by respective prime movers. The prime movers run at a governed rated speed but slow down with overload and may stall if the load is not decreased quickly. A sensor determines the frequency of the generator and provides a frequency feedback signal. This is compared to a set frequency signal related to the speed of the prime mover and the generator …
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 March 10, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 10, 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.