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:
Apr. 10, 2012
Filed:
Jun. 10, 2009
George B. Yundt, Andover, MA (US);
David S. Colson, Wakefield, MA (US);
George B. Yundt, Andover, MA (US);
David S. Colson, Wakefield, MA (US);
Kollmorgen Corporation, Radford, VA (US);
Abstract
A system and method are provided for improved dynamic braking in AC motors with an electronic drive, and more particularly to using a current regulation circuit to control the current supplied to the motor to be in phase with the internal EMF voltage of the motor such that the braking torque of the current is maximized per ampere of dynamic braking current when needed to stop the motor in case of a control failure or emergency. A current regulator produces a voltage command to the motor based on the current command input. The motor is still controlled by a d-q current regulator and the q-axis (torque axis) voltage is driven to zero while the d-axis (non-torque axis) is left in current control with a zero current command. This way the motor internal voltage drives a current in the terminals of the motor but the current is in phase with the internal voltage of the motor. Since the current loops are still active, current limiting may be implemented and the dynamic brake current amplitude can be well controlled and entirely goes into stopping the motor.