基于主从能量控制的MMC-MTDC盈余功率消纳策略OA

Modular multilevel converter based multi-terminal direct current(MMC-MTDC)systems rely on energy-dissipating devices to handle surplus power caused by AC-side faults at the receiving-end,which suffers from poor economic efficiency and significant energy waste.To fully exploit the inherent surplus power absorption capability of MMC-MTDC systems and reduce dependence on energy-dissipating devices.A master-slave energy coordination strategy is proposed for interactive power absorption among multiple converter stations.Firstly,an MMC-MTDC control model is established,and the feasibility of surplus power absorption through energy-based control is analyzed.Subsequently,a three-dimensional energy model of the MMC is introduced to achieve decoupled energy control for each pole of the converter stations.Based on a simplified MMC-MTDC system model,active energy control schemes are designed for different types of converter stations.Furthermore,inspired by the master-slave control concept,a timing-based energy coordination logic is developed to address various AC-side fault scenarios at different receiving-end stations and two categories of surplus power levels,thereby enabling coordinated utilization of available energy margins across multiple converter stations.Finally,a MMC-MTDC system is implemented in PSCAD/EMTDC for simulation validation.Results demonstrate that the proposed strategy effectively coordinates multiple converter stations energy control without requiring energy-dissipating devices.The strategy can adapt to diverse surplus power conditions and successfully achieve fault ride-through.