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:
Nov. 06, 2001
Filed:
Feb. 29, 2000
Peter W. Hammond, Greensburg, PA (US);
Richard Osman, Pittsburgh, PA (US);
Robicon Corporation, New Kensington, PA (US);
Abstract
An electric drive apparatus and method for controlling AC motors wherein the motor output is a function of the AC input power to the electric drive. Means are provided for detecting the voltage being supplied by the source of AC power to a drive circuit, and for controlling the output to the multi-phase AC load based on the detected power level. A controller monitors the motor voltage, current, and speed or frequency while also receiving a command for torque or torque-producing current. The method provides for the operation of the drive circuit in the event of either a partial or complete loss of AC input power. During such an occurrence, the controller will cause the circuit to generate sufficient negative torque to cause a power flow from the motor to the drive circuit to substantially equal the inherent losses in the drive and motor to avoid loss of energy from the DC filter of the drive circuit. Motor torque and speed can be quickly restored when the input power is re-established.