Using Fast Frequency Response Services to Improve Frequency Stability of Low Inertia Power Systems

The increasing penetration of non-synchronous renewable energy sources (NS-RES) has led to a decrease in power systems inertia which introduces major challenges to frequency stability. This paper investigates impacts of inertia location and network topology on frequency stability of power systems by the means of time domain simulations. We assess the contribution of fast frequency response (FFR) services on frequency performance of the system by considering the impact of FFR controller activation time delay. Furthermore, we derive analytical expressions to approximate rotor frequency and rate of change of frequency (RoCoF) which show that the impacts of reduced inertia can be studied by avoiding computationally extensive simulations. The results show that the FFR services provided by the NS-RES are attractive options in low inertia power systems.