Transient Stability Enhanced Control of GFMC-GFLC Paralleled Connected to Grid System

The grid-following converter (GFLC) has a relatively fast dynamic response speed but cannot provide voltage-frequency support. The grid-forming converter (GFMC) has a slow dynamic response speed and requires additional energy storage to support the DC voltage. Therefore, microgrids composed of both grid-forming converters (GFMC) and grid-following converters (GFLC) is a vital structure of dual high-power systems. However, the complex interaction of heterogeneous converters leads to a sharp increase in the risk of instability. The current synchronization control of grid-connected converters is all based on the SMIB system, without considering the heterogeneous interaction. To bridge this gap, this paper proposes a transient damping control to mitigate the adverse effects of interaction and thus enhance transient stability. Simulation and RT-Lab-based hardware in the loop experiments verify the superiority and the robustness of the proposed stability-enhanced control.