Power Quality and Dynamic Performance Improvement of Wind Farms Using a STATCOM

This paper investigates the use of a static synchronous compensator (STATCOM) to improve the power quality and fault ride-through capability of a wind farm equipped with fixed- speed wind turbines driving squirrel-cage induction generators. Two different control schemes are developed to control the STATCOM; one is a conventional linear PI control scheme, and the other is an input-output feedback linearization (IOL) based nonlinear control scheme. Simulation studies are carried out in the PSCAD/EMTDC environment to examine the performance of the wind farm with and without the STATCOM. Results show that the STATCOM significantly reduces the voltage fluctuations caused by wind speed variations and enhances the fault ride- through capability of the wind turbines. Compared to the linear PI control, the nonlinear IOL control provides the STATCOM with the same performance for voltage fluctuation mitigation and transient PCC voltage regulation, but with an improved performance for transient dc-link voltage regulation.