Enhancement of SDRU and RCC for low voltage ride through capability in DFIG based wind farm

Abstract

Grid-integrated wind turbine may experience low voltages during transient events in grid. An increase observed in inrush current leads to low voltage. To control the increased current, an enhancement in a low voltage ride-through (LVRT) capability is required. This study examines the impact of an LVRT scheme on grid-integrated doubly fed induction generator (DFIG)-based wind turbines which are represented with new stator-damping resistor unit (SDRU) and rotor current control (RCC). Besides, both stator and rotor circuits of DFIG were enhanced with electro-motor force (emk). Designed as hybrid with SDRU and RCC, DFIG was examined to analyses symmetrical and asymmetrical faults in the grid. Electro-motor-force dynamic modeling of both stator and rotor was developed. The responses of wind turbine against low voltage are investigated in terms of bus voltages, angular speed, electrical torque, stator and rotor current, and d–q axes current. The results of the study show that the system became stable in a short time when the SDRU and RCC were incorporated with the stator and rotor electro-motor-force models.