Grid Forming MMC-HVDC for Enhanced Renewable Energy Integration in Interconnected Power Systems

With the increasing penetration of renewable energy generation, the fluctuating power output and widespread use of power electronic devices pose significant challenges to power grid stability. Enhancing the grid integration and long-distance transmission capacity of largescale renewable energy has become a critical technical challenge. Existing research primarily focuses on the gridconnected characteristics of individual inverters, while research on the overall stability of power systems with largescale renewable energy inverter integration remains relatively limited. This paper establishes an electromagnetic transient simulation model of a large-scale power grid with a high proportion of renewable energy integration. Furthermore, it investigates the dynamic response characteristics of various grid-forming control strategies under unified inverter control architecture within an MMC-HVDC based DC partitioned grid system. Simulation results based on the IEEE 39-bus system demonstrate that the proposed system enables power sharing between geographically separated grid partitions, effectively reduces energy storage requirements and short-circuit current levels, and provides a novel approach for planning and control strategies for large-scale renewable energy grid integration.