Current chopping strategy for switched reluctance machines
CA 2010673 C · Owner: General Electric Company · Inventors: Turnbull, Fred Gerdes; Macminn, Stephen Richard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus are provided for controlling the switching devices in a switched reluctance machine bridge inverter having at least two switching devices per phase. One switching device is used for hysteresis band current chopping to regulate phase current magnitude while the other, switching device, in combination with a flyback diode provides a circulating path for phase current. Alternatively current chopping and circulating are, alternated between both switching devices during each conduction interval of the corresponding machine phase. Ripple current is decreased thereby reducing the required, size of the DC link capacitor. Switching losses are also reduced.
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
- Filed February 22, 1990 and granted May 18, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 22, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 22, 2012.
- 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.