Analysis of Synchronverter Self-Synchronization Dynamics to Facilitate Parameter Tuning

This paper proposes a self-synchronizing synchronverter controller design that leverages the addition of a virtual resistance (along with a suitable coordinate transformation) to compute feedback signals during self synchronization prior to grid connection. With respect to analysis, we exploit separation-of-time-scales arguments and develop appropriate reduced-order models, which are well-suited for studying phase-angle and voltage-magnitude self-synchronization dynamics independently. Our work provides analytical justification for the effects of pertinent controller parameters and system initial conditions on self-synchronization dynamics observed empirically in time-domain simulations. As such, it offers practical guidance on favourable parameter-value settings to achieve fast self synchronization, and it yields accurate estimates for self-synchronization times with well-tuned parameters. Through numerical simulations and experiments, we illustrate the efficacy of the proposed controller design and verify the validity of subsequent analyses.