Research on the Control Method of a Three-Port Energy Router Considering Regenerative Braking Energy in Railways

With the continuous expansion of electrified railway operating mileage, achieving energy-efficient railway operations has become imperative. The effective utilization of regenerative braking energy is key to reducing energy consumption. This paper proposes a regional Three-Port Energy Router (TPER) to facilitate the conversion and control of energy flows between the railway traction power supply system, microgrid, and Energy Storage System (ESS) across various forms of electrical energy and voltage levels. The TPER employs a communication-based hierarchical control approach for energy dispatch, enabling effective energy management and scheduling. To address the presence of multiple power electronic devices in the microgrid, the secondary grid-connected inverter control adopts a PQ control strategy based on Hilbert transform with a phase-locked loop (PLL) free structure, eliminating the errors and noise effects introduced by traditional PLLs and enhancing the precision and reliability of power quality control. Finally, through simulation analysis and the establishment of a hardware-in-the-loop (HIL) simulation experiment, the effectiveness and feasibility of the proposed method are verified.