Enhancing LVRT capability of FSIG wind turbine using current source UPQC based on resistive SFCL

Abstract

This paper presents a current-source converter based unified power quality conditioner (UPQC) is used for a fixed-speed induction generator (FSIG) wind turbines in order to enhance the low voltage ride through (LVRT) capability. When voltage sag occurs due to grid side fault, the series compensator of the UPQC injects required voltage to prevent disconnecting of FSIG wind turbine. On the other hand, faults produced by wind turbine generator systems will impact not only the wind farms but also the interconnected system including the grid if proper protection is not ensured. Therefore, the resistive SFCL incorporated in series with the dc-link inductance of UPQC is proposed to limit excessive current in the event of the generator side fault. Detailed simulation studies implemented in PSCAD/EMTDC confirm that both of resistive SFCL and large dc-link inductance are effective in decreasing the fault current thereby reducing the voltage dip at the generator terminal.