Key Parameters Design of Grid-Forming VSC-HVDC Station with Inertia Supporting Function

With the increasing penetration of non-synchronous energy sources, the insufficiency of power system inertia has become a critical challenge. Grid-forming VSC-HVDC station can emulate synchronous generators characteristics through virtual synchronous control to enhance grid stability, yet their inertia support capability is inherently constrained by the overload tolerance of switching devices. This paper establishes a small-signal model of the VSM, derives analytical expressions for station power response under frequency step disturbances, and reveals the mapping relationships between key parameters and the overload current of switching devices. The study demonstrates that the inertia constant positively correlated with the overload current of switching devices, and bridge arm inductance exerts a reverse regulatory effect on overload current by modulating the synchronizing power coefficient. The accuracy of the theoretical analysis is validated through PLECS simulations. The findings offer theoretical guidance for parameter design and device selection in Grid-Forming VSC-HVDC station.