A Review of Energy Management for Distributed PV-Storage-Integrated Railway Traction Power Supply Systems: Architectures, Interfaces, and Control Strategies

Railway traction power supply systems (TPSSs) are evolving from passive grid-fed infrastructures into active energy systems with local photovoltaic (PV) generation capacity, energy storage systems (ESSs), and converter-based regulation. Unlike conventional microgrids, TPSSs feature single-phase, highly dynamic traction loads; short-duration regenerative braking bursts; and strict constraints on voltage quality, stability, and protection. These characteristics make the energy management of distributed PV-storage-integrated TPSSs a distinct research problem. This review examines the field from three coupled perspectives: supply architecture, power electronic interfaces, and energy management strategies. First, representative integration architectures are classified into substation-side, wayside-distributed, and hybrid multi-port schemes. Second, converter interfaces and flexible traction substations are analyzed as the enabling layer for coordinated control of PV, ESS, the utility grid, and traction feeders. Third, major energy management strategies, including rule-based, optimization-based, hierarchical multi-timescale, and uncertainty-aware methods, are compared. The review further discusses power quality, stability, protection, and battery degradation constraints that shape practical deployments. Finally, research gaps and future directions are identified to further the development of more robust, railway-specific, and implementation-oriented PV-storage energy management.