The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 05, 2007
Filed:
Jul. 14, 2005
Mahesh M. Swamy, Gurnee, IL (US);
Brian Geoffrey, New Berlin, WI (US);
Yoshiaki Yukihira, Buffalo Grove, IL (US);
Mike Rucinski, Kenosha, WI (US);
Mahesh M. Swamy, Gurnee, IL (US);
Brian Geoffrey, New Berlin, WI (US);
Yoshiaki Yukihira, Buffalo Grove, IL (US);
Mike Rucinski, Kenosha, WI (US);
Yaskawa Electric America, Inc., Waukegan, IL (US);
Abstract
A motor control for a reciprocating load includes overvoltage suppression. The motor control comprises a variable frequency drive (VFD) operatively connected to a power source for operating a motor to drive the reciprocating load. A sensor determines motor torque. A control unit is connected to the VFD and to the sensor and is adapted to control the VFD in a normal mode to operate the motor at a select reference frequency. The control unit predicts occurrence of a negative motor torque condition based on sensed motor torque and in response to a negative motor torque condition controls the VFD in a negative motor torque mode to operate the motor at a higher frequency than the select reference frequency to prevent the motor from entering a negative slip condition.