Enhancing voltage stability and LVRT capability of a wind-integrated power system using a fuzzy-based SVC

 This paper studies the SVC performance in a single machine (doubly fed induction generator (DFIG) employed in a wind farm) infinite bus (SMIB) system. The SVC is employed to improve the voltage stability of the system and the low voltage ride-through (LVRT) capability of the wind farm. To enhance the effectiveness of the SVC, a supplementary fuzzy-based controller (FC) is proposed and is integrated into the SVC controller. The use of the proposed FC leads to the increasing the accuracy of the SVC controller that results in improving its performance in both transient and steady state. By using the proposed controller, the steady state voltage is enhanced and the maximum voltage drop under fault situations is decreased. Less voltage drop after the fault occurrence using the proposed FC results in improving the LVRT capability and makes the wind farm able to meet the grid code requirements in a larger range of load variations in the system. Using extensive simulations in MATLAB/ Simulink, the effectiveness of the proposed method in improving the voltage stability and LVRT capability is validated and its effects on the performance of the DFIG-based wind turbine are studied.