Impact of steady-state grid-frequency deviations on the performance of grid-forming converter control strategies

The aim of this paper is to investigate the impact of steady-state deviations in the grid-frequency on the performance of grid-forming converter control strategies. In particular, the virtual synchronous machine (VSM) control structure has been the focus of study in this paper. Two alternative solutions to address the issue with the conventional VSM structure are suggested, and their impact on the active power response and the power dissipation properties of the converter are compared. For the latter, the ac-side input admittance of the grid-connected converter is derived for the different control structures under consideration. Finally, the dynamic performance of the different control structures is verified through the time-domain simulations.