Impact of variable speed wind farms on power systems oscillations

This paper presents a qualitative development for assess the main factors affecting the damping of the oscillation modes when wind farms based on variable speed turbines are incorporated in power systems. It will be shown that the main effects that determine the degradation or improvement of mode damping due to wind power generation lies in the alteration of the operating points of the involved synchronous generators and the nature of the oscillatory modes affected. It is also analyzed the effect of reactive power exchange between wind farms and the power grid on oscillatory behaviour. Such developments are validated by performing simulations on a 2017 peak scenario for the Uruguayan transmission system, which shows a strong interaction between the pre-existent hydro power plants and future wind farms to be incorporated¹.