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:
Sep. 11, 2012
Filed:
Mar. 17, 2008
Jörg Kretschmann, Kempen, DE;
Jörg Kretschmann, Kempen, DE;
Woodward Kempen GmbH, Kempen, DE;
Abstract
The invention relates to a method and a device for operating an asynchronous motor () with double feeds, having a stator () connected to a grid and a rotor () connected to an inverter (), said inverter () being designed such that it impresses a target value for an electrical variable in the rotor (). In a method according to the invention, after detecting a transient grid voltage change, a target value for the electrical variable determined from at least the rotor flux and the stator flux is impressed in the rotor () such that an active reduction in the torque occurring during the transient grid voltage change is achieved. The target value of the electrical variable is preferably determined from a suitable weighting of the stator flux, rotor flux, stator voltage, stator current, rotor current, and, if available as a measured variable, stator voltage.; In this manner, torque peaks are similarly prevented for various types of grid faults, and the maximum time value of the rotor current is optimally reduced, and a rapid return to regular operation of the asynchronous motor is made possible.