Design And Control Of A Hybrid Energy DC Energy Router

A Direct Current(DC)micro-grid can integrate various renewable energy and energy storages for efficient power dispatching and scheduling.DC energy router provides energy management for DC micro-grid cluster within a broader geographical range,improving energy utilization and safety.Partial power converters offer high conversion efficiency,however,the steady-state operating range and fault-handling capabilities is relatively limited comparing to full(cascaded)power converters.To simultaneously enhance energy scheduling efficiency and engineering feasibility,this study will investigate a novel DC energy router with a hybrid energy transfer structure.Taking three DC energy communities as research objects,partial power converters are constructed using half-bridge basic units to realize multi-port DC energy routing.Between the floating potential of this partial power converter and the DC ground,a full-power converter is proposed to manage zero-sequence current,forming a hybrid energy transfer topology.The small signal model of the hybrid energy DC energy router was investigated,and a constant current scheduling control strategy and a constant voltage cut-in strategy were designed based on this model.The feasibility of the topology and power scheduling of the DC energy router was demonstrated,and circuit parameters were optimized.Since the system has two types of power transfer channels(cascaded and series),simulation was used to investigate operational efficiency optimization.The relationship between local loss and global loss was analyzed,a loss simulation model was constructed,and the system operation efficiency curve description was obtained by simplifying operating conditions.An efficiency-optimized DC energy scheduling strategy was designed.A hardware experimental platform was built,using supercapacitor to simulate the DC bus,and the feasibility of hybrid energy transfer was experimentally verified.Various scheduling experiments and mode swapping experiments were completed on the hardware platform,demonstrating that the hybrid energy transfer topology can provide flexible and reliable energy routing for DC energy communities.