Improved single-phase self-synchronised synchronverter with enhanced dynamics and current limitation capability

Inertia-less power converters are one of the main obstructions to increase the penetration level of distributed energy resources in the utility grid. The stability of the power system mainly depends on the system inertia. Virtual synchronous machine and synchronverter-based grid-tied inverters have been introduced as a solution to this problem. Here, a modified self-synchronised synchronverter is introduced to enhance the dynamic response of the active power loop and to limit the injected active/reactive power to the grid. Furthermore, the injected current to the grid is limited during faults employing proportional–resonant-based inner current loop. Feed-forward voltage is implemented in the current control loop to achieve seamless transfer between standalone and grid-connection modes of operation. Extensive simulation and experimental results are obtained to verify the proposed enhanced controller.