Development of linear models of Static Var Compensators suitable for enhancing performance of power systems including wind farms

In this work, the design of fixed-gain Proportional–Integral–Derivative (PID) controllers with multiple stage lead-lag compensators are investigated for improving further the dynamic impact of Static Var Compensators (SVCs). The analysis is based on the linearisation of the power system under study and the proper shift of critical eigenvalues, associated with the SVC and electric network, to the desired locations. In order to linearise the SVC an established fourth order model is used and the development of more complex models is attempted. This study deals with the development procedure of two different high order models for the SVC. Finally, one of them is adopted along with the fourth order model in order to design two different fixed-gain PID controllers with the multiple stage lead-lag compensator. The suitability and effectiveness of the resulted fixed-gain PID controllers is tested by performing digital simulations of a Greek power system including a wind farm under investigation.