Inertial and Damping Based Optimal Control for Grid-Forming Converter

The grid-forming converter need to balance its dynamic response capability and static control accuracy, which is controlled by inertia and damping coefficient. Normally inertia works as grid frequency changes, while damping coefficient suppress its oscillation. This paper improves restoring stability by increasing damping channel for grid-forming converter, meanwhile its inertia channel is improved to speed up the restoration of stability time. Based on the active small-signal zero-pole distribution determine the damping, and determine the time constant and proportional coefficient respectively based on the Bode plot and root—locus distribution before and after improvement. The simulation results verify that the inertial and damping based optimal control balance the contradiction between stability and steady-state accuracy as grid-forming converter response to frequency regulation.