Patents by Inventor Robert R. Zeranski

Robert R. Zeranski has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5550450
    Abstract: Polarity change of a feed-forward compensation signal for compensating for a dead-time voltage disturbance is synchronized with zero crossings of a load current reference. The load current reference is advanced in time by adding a fixed phase angle, scaled by the synchronous frequency, to the synchronous coordinates angle. The load current reference is time-advanced only for timing the polarity change of the feed-forward compensation signal and not for application to the current regulators; the current regulators still use the load current reference (unadvanced). For a converter, the load current would be an AC mains input current. For an inverter, the load current could, for example, be an induction motor stator current. The shape of the feed-forward compensation signal is approximately trapezoidal and is obtained from the limited, amplified, advanced load current reference.
    Type: Grant
    Filed: April 28, 1993
    Date of Patent: August 27, 1996
    Assignee: Otis Elevator Company
    Inventors: Joseph Palko, Robert R. Zeranski