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. 15, 2014
Filed:
Sep. 11, 2008
Stephan Engelhardt, Sonsbeck, DE;
Joerg Kretschmann, Kempen, DE;
Stephan Engelhardt, Sonsbeck, DE;
Joerg Kretschmann, Kempen, DE;
Woodward Kempen GmbH, Kempen, DE;
Abstract
The invention relates to a method to control power output of a doubly-fed induction machine to a grid including the steps of measuring grid voltage and grid current in a three phase coordinate system, transforming grid voltage and grid current into a stator frame coordinate system, decomposing the grid voltage and grid current in the stator frame coordinate system in a positive sequence system and in a negative sequence system, calculating active and reactive power in the positive and negative sequence system, and controlling active and reactive power in the positive and negative sequence system. The object to provide a method to control power output of a doubly-fed induction machine which provides good dynamics and is able to allow fault-ride-through operations when unbalanced grid voltages occurs is solved in that active and reactive power in the positive and negative sequence system are used as independent state variables in a state controller, whereas the state controller generates manipulated values in the positive and negative sequence system separately which are subjected as manipulated state vectors to a state feedback in a stator frame coordinate system without further control loops before the manipulated vector resulting from state feedback is used to set the rotor voltage.