Improved Grid Fault Ride through capability of DFIG using Fuzzy controlled Dual Output Converter

Abstract

Doubly Fed Induction Generator (DFIG) based wind energy conversion system (WECS) are affected due to power quality problem under voltage sag condition. Voltage sag occurs in grid side due to heavy load is interfaced with the normal load or grid faults. The proposed system is modified connection of doubly fed induction generator (DFIG) with Grid Fault ride through capability for wind energy conversion systems (WECSs) using Dual output inverter during LLLG fault. The Dual Output Converter (DOC) can provide two set of independent output terminals, the first set of output terminals are connected to the grid to produce reliable output to grid during regular operating mode and during grid fault mode, the second set of output terminals are connected to finishing end of the stator windings to provide Grid Fault Ride-Through (GFRT) ability to the modified architecture of DFIG. Grid Fault Ride Through (GFRT) is obtained using Fuzzy based intelligent control algorithm for proposed system during all kind of grid faults and maintain the grid voltage profile with increase reactive power during voltage sag. This proposed system improve overall power quality at a lesser number of converter switches and reduced cost compared with DVR. The value of the system is estimated through detailed simulation studies using MATLAB.