Fault-Ride-Through Capability of VSG-Based Grid-Forming Converters

Grid-forming virtual synchronous generator (VSG)-based converter has a promising potential to be used as an interfaced converter for high penetration of renewable energy resources. Although emulating inertia and oscillation damping features in the control scheme of converters is possible, the short-circuit behavior of synchronous machines during fault conditions or other large-signal disturbances is not replicable in these converters, as their semiconductor devices are current-sensitive. This paper proposes a modified control technique for grid-forming VSG-based converters, enabling their fault-ride-through capability during fault situations. The proposed control technique limits converter current to its allowable amount while prevents windup in the outer control loops. To validate the performance of the proposed control technique, simulation results in Matlab/Simulink are provided and discussed in detail.