A Novel Method for Synchronizationof DFIG in an Unbalanced System

Due to the increasing installations of wind turbines worldwide and their specialinstalling conditions, study of the impact of power quality parameters on these turbinesseems to be necessary. Analysis of DFIG model shows unbalance in this system couldhave three effects, which one of them is the wrong detection of the net phase. This paperpresents a new phase locked loop structure, which solves this problem and detects thepositive phase sequence correctly. In this structure the effect of unbalanced voltage onPLL performance is eliminated by subtracting the unbalanced value of d and q signalsfrom main voltage, so unbalanced effects don’t scenes by PLL. Simulation results ofproposed method compared with similar structure proved its performance.

Keywords:

DFIG , PLL , Synchronization