Stability of Future Low-Inertia Power Systems with Different Grid-forming Control Schemes

Different grid-forming and grid-following inverter control and synchronization schemes can affect and support the low-inertia power system frequency stability in different ways. It is of key importance, however, that frequency stability can be always secured with varying shares of grid-forming and grid-following inverters as well as rotating generators. This paper presents case studies with variable shares of two different type of grid-forming inverter-based resources, grid-following inverters and synchronous generators. Case studies are done with a simple power system modelled with PSCAD to study the effect of these resources on frequency stability after a load increase. In overall, paper presents multiple proposals to further improve frequency stability by enhanced control of the studied grid-forming inverters in the simulated cases.