Using power system stabilisers in doubly fed induction generators

This article deals with the design and usage of a power system stabiliser (PSS) and its impact in the controller of a doubly fed induction generator (DFIG). Eigenvalue analysis and numerical simulations are used to design and tune the PSS for different types of input signals, and the suitability of the signals is assessed. The impact of large scale wind farms utilising DFIGs on the oscillations of a conventional power system is compared to the impact of conventional generators in a test power system. The dynamics of a wind farm can be represented by a third order DFIG model and a simple controller model. Modal analysis and dynamic simulations are used to demonstrate the contribution made by the wind farm to power system damping. Numerical simulations show that DFIGs, such as those found in wind farms, are capable of damping oscillations.