A feedforward control for increasing the damping effect of enhanced current-controlled virtual synchronous generator

•Enhanced current-controlled virtual synchronous generator with feedforward controller is proposed.•Feedforward controller affects mainly the low-frequency roots without worsening VSG inertial response.•Enhanced CC-VSG ensures stable operation in a wide range of grid strength conditions. Novel grid-forming control strategies based on the virtual synchronous generator (VSG) algorithm are becoming a key technology for power converters in modern hybrid power systems. This paper considers an alternative current-controlled VSG structure (CC-VSG). However, this structure is complex third-order system and is characterized by the lack of damping torque when the grid strength changes. Therefore, in this paper an enhancement of the CC-VSG damping properties via a feedforward controller is proposed. The analysis of the closed-loop transfer function demonstrates the reduction of the model order to the second order due to the proposed controller. By analyzing the state-space model, the predominant impact of the gain of the developed controller on the low-frequency roots is proved. As a result, it is concluded that the enhanced CC-VSG structure is efficient, stable and can be flexibly tuned to obtain any desired dynamic response under different grid strength conditions and load variation.