Low voltage ride-through of wind farms using STATCOM combined with series dynamic breaking resistor

Wind farms are confronted with increasing demands for power quality and fail-safe operation at grid fault. State-of-art techniques applied to meet low voltage ride-through (LVRT) requirements for fix speed wind farms are blade pitching and dynamic reactive power compensation. Besides, breaking resistor and energy storage unit is also helpful to LVRT performance. However, these approaches have their own limitations. A hybrid of STATCOM and series dynamic breaking resistor (SDBR) to realize LVRT performance is proposed in this paper. Utilization of STATCOM overcomes the drawback of SDBR while the SDBR greatly reduces STATCOM rating. Comparisons of the proposed system and some other systems were presented and validated by SABER with a representative model. Simulation results indicate that good LVRT performance can be achieved with low rating of STATCOM. It is also shown that the combination shares the electrical stress of the three phases during unbalance fault.