OVERVIEW OF LOW-VOLTAGE RIDE-THROUGH SOLUTIONS FOR DFIG WIND TURBINE SYSTEM

Abstract

Doubly-fed induction generator wind turbines are very sensitive to grid disturbances, especially to voltage dips, since they are connected directly to the grid. The ability of a wind turbine to survive a short voltage dip without tripping is referred to as the low-voltage ridethrough (LVRT) capability. Crowbar, dynamic voltage restorer (DVR) and energy storage system (ESS) are the solutions which are adopted in this study. In order to test the LVRT capability of the wind turbine system, the PSCAD/EMTDC simulation has been performed for a 2 MW DFIG wind turbine system. In comparison of the LVRT techniques, although the ESS, with relatively high cost, outperforms the crowbar, the DVR system presents the best performances of the wind turbines through keeping the stator voltage at constant under grid fault condition despite the balanced and unbalanced voltage dips as well as normal condition.

Keywords: Crowbar, doubly-fed induction generator (DFIG), dynamic voltage restorer, energy storage system, voltage sag.