Control strategies for DFIG wind turbines under grid fault conditions

摘要

The classical control techniques for regulatingudthe active and reactive power delivery in doubly fedudinduction generators (DFIG), for wind power applications,udare normally based on voltage oriented control (VOC)udstrategies. Among these algorithms, those that work in audsynchronous reference frame, attached to the magneticudflux vector, became very popular. In spite of the goodudbehaviour of such algorithms their performance dependsudhighly on an accurate detection of the stator flux position,udsomething that can be critical under unbalanced oruddistorted grid voltage conditions. This paper presents audnew VOC strategy able to control the operation of a DFIGudin the αβ reference frame, with no need of flux positionudestimation, something that conducts to a more simple andudrobust algorithm. In order to evaluate the advantages ofudthis new control proposal, namely VOC-RRF, theirudperformance will be compared with the response obtainedudwith a classical VOC algorithm by means ofudPSCAD/EMTDC® simulation models.