Development of linear models of static var compensators and design of controllers suitable for enhancing dynamic/transient performance of power systems including wind farms

In this work the design of controllers with fixed-gain PID and multiple-stage lead-lag compensators is investigated for improving further the dynamic impact of static var compensators (SVCs). The analysis is based on the linearization of the power system under study and the proper shift of critical eigenvalues, associated with the SVC and electric network, to desired locations. In order to linearize the SVC an established 4th order model is used and the development of a more complex model is attempted. Finally, a 16th order linear model is developed for the SVC by implementing system identification methods, and this model is used along with the 4th order model to design two different controllers with fixed-gain PID and a multiple-stage lead-lag compensator. The suitability and effectiveness of the resulted controllers are tested by performing digital simulations of a Greek power system which includes a wind farm.