Comparison of MMC-HVDC Control Operation Modes and System Influences

The focus of the paper is on the analysis of the impact of an embedded MMC HVDC link on the dynamic stability of the AC system with different load flow scenarios and control strategies. The effect of operating point of a VSC HVDC link and the control strategies employed in VSCs are analyzed in particular. It is shown that both these factors can substantially affect the damping performance of the AC network. Both modal analysis and transient stability analysis are used, in a complementary way, to study the electromechanical performance of the integrated AC/DC model. The 53-bus, 24-generator, AC network developed based on a real network, but sufficiently simplified to allow fundamental phenomena to be explored, is used in the study.