Changes
|bgcolor = "#DCE6F1"|French Keywords
|bgcolor = "#DCE6F1"|Claims, Title, and Abstract
|bgcolor = "#DCE6F1"|((((doubl<nowiki>*</nowiki>3 OR dual<nowiki>*</nowiki>3OR ADJ two OR deux) NEAR4 (nourris OR feed<nowiki>*</nowiki>3 OR puissance OR sortie<nowiki>*</nowiki>1 OR contrôle<nowiki>*</nowiki>1)) NEAR4 (induction OR asynchroneasynchron<nowiki>*</nowiki>1) NEAR4 (générateur<nowiki>*</nowiki>1 OR generator<nowiki>*</nowiki>1 OR machine<nowiki>*</nowiki>1 OR dynamo<nowiki>*</nowiki>1)) OR dfig or doig)
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==Sample Analysis==
A sample of 139 patents from the search are analysed analyzed based on the taxonomy.
Provided a link below for sample spread sheet analysis for doubly-fed induction generators.<br>
===Patent Analysis===
|bgcolor = "#DCE6F1"|Method of and apparatus for operating a double-fed asynchronous machine in the event of transient mains voltage changes
|bgcolor = "#DCE6F1"|The short-circuit-like currents in the case of transient mains voltage changes lead to a corresponding air gap torque which loads the drive train and transmission lines can damages or reduces the drive train and power system equipments.
|bgcolor = "#DCE6F1"|The method presents that the stator connecting with the network and the rotor with a converter. The converter is formed to set a reference value of an electrical amplitude in the rotor, by which a reference value of the electrical amplitude is setted set in the rotor after attaining a transient mains voltage change, such that the rotor flux approaches the stator flux.
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|Variable speed wind turbine with doubly-fed induction generator compensated for varying rotor speed
|The DFIG system has poor damping of oscillations within the flux dynamics due to cross coupling between active and reactive currents, which makes the system potentially unstable under certain circumstances and complicates the work of the rotor current controller. These oscillations ca damage the drive train mechanisms.
|A comprensation compensation block is arranged, which feeds a compensation control output to the rotor of the generator. The computation unit computes the control output during operation of the turbine to compensate partly for dependencies on a rotor angular speed of locations of poles of a generator transfer function, so that the transfer function is made independent of variations in the speed during operation of the turbine which eliminates the osicllations and increases the efficinecy of the wind turbine.
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