Improved low voltage ride-through of wind farm using STATCOM and pitch control

Nowadays, wind farms are confronted with increasing demands for power quality and fail-safe operation at grid voltage failure. Grid codes currently demand for low voltage ride-through capability to a very low value (10% of its nominal value) and support of the grid voltage by supplying reactive current until fault clearance. This paper emphasizes on the analysis of torque-slip characteristics of induction generator. STATCOM, in combination with pitch control is considered to improve the LVRT capability of wind farms with fixed speed induction generators (FSIG). The simulation model for low voltage ride through developed in PSCAD/EMTDC is presented. Simulation results demonstrate that these methods can enhance wind farms low-voltage ride through (LVRT) capability and the wind turbines can restore to normal operation under the specified control scheme.