Virtual Inertia Control Using Modular Multilevel Converters: Application to Constant Voltage Constant Frequency Terminal of HVDC Systems

This paper applies a virtual inertia control using the stored energy in a modular multilevel converter (MMC) to a constant voltage constant frequency (CVCF) terminal of HVDC systems. The authors analyze the relationship between CVCF control of the MMC and the virtual inertia created by the MMC. The theoretical analysis reveals that the MMC can increase inertia by decreasing output voltage of MMC by the CVCF control even if there is no additional energy storage in MMC. The effectiveness of the proposed control method is verified by computer simulations.