Emerging Frequency Control Mechanisms in IBR Dominated Power Systems.

As inverter-based resource (IBR) penetration increases, system inertia levels are decreasing and the type of frequency response available is changing. This paper explores the adequacy of emerging technologies in providing post-contingency frequency control in the absence of traditional synchronous generators (SGs). The three technologies considered are (1) the fast frequency response (FFR) of a wind turbine generator, (2) the FFR of grid-scale battery systems and (3) the inertial contribution of synchronous condensers (SCs). The model incorporating these technologies is built using the aggregated swing equation and includes the primary frequency responses of steam and hydro generators. The findings indicate that although no individual technology can adequately improve the frequency response, combinations of them can. For example, SCs and batteries were seen to maintain the rate of change of frequency (RoCoF) and nadir within safe operating levels. This suggests that a more granular set of grid services is required to maintain system stability and that these services can be offered by a range of new technologies.