Frequency control based on sensing voltage fed to an induction motor
CA 2017074 C · Owner: Seibel, Brian J. · Inventors: Kerkman, Russel J.; Seibel, Brian J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A frequency control method is incorporated in a motor drive to prevent overcurrent trips when an induction motor is subjected to impact loads or reconnection under load. The drive includes a current regulator loop to control stator current and a voltage regulator loop to control the command to the current regulator. Motor voltage is sensed and a voltage error is developed. This voltage error is processed through a proportional-integral control loop which controls an operating frequency signal to the current regulator. The drive responds during current limit conditions to reduce operating frequency and speed until the current limit conditions subside. The motor can then be re-accelerated up …
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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 17, 1990 and granted March 12, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 17, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 17, 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.