Improving power quality and stability of wind energy conversion system with fuzzy-controlled STATCOM

Abstract

Fixed speed induction generator (FSIG)-based wind farms have poor low voltage ride through (LVRT) capacity and poor power quality and stability due to insufficient reactive power support during disturbances. Flexible AC transmission systems (FACTS) devices such as static synchronous compensator (STATCOM) can improve the LVRT capacity and power quality and stability of FSIG-based wind energy conversion system (WECS). Proportional and integral (PI) controllers are often used to control the operation of the STATCOM. However, since WECS is highly non-linear and subject to various disturbances, the PI-controlled STATCOM cannot provide optimal performance for different operating points. More robust controllers such as controllers based on fuzzy logic approach are required for the STATCOM to provide adequate dynamic voltage control and to improve power quality and stability of the WECS. This paper presents the design of fuzzy logic-based controller of a STATCOM for improving the power quality and stability of a WECS. Comparison study of PI-controlled and fuzzy logic-based STATCOM is carried out using SimPowerSystem in MATLAB/Simulink environment. The simulation results show that the fuzzy logic-based STATCOM controller provides better system dynamic response and hence improves power quality and stability for the WECS.