Overview of resilient traction power supply systems in railways with interconnected microgrid

In recent years, the achievement of a renewable and sustainable traction power supply system (TPSS) in the rail sector has become a significant challenge. Focusing on this issue, this paper firstly provides a comprehensive overview and classification of the state-of-art TPSSs in DC and AC railway. Then, together with low voltage (LV) DC, medium voltage (MV) DC, LV AC, and hybrid AC/DC interconnected microgrid (IMGs), various architectures of resilient TPSSs are proposed for renewable energy integration into DC and AC railway. The resilient TPSS offers on-site access and local consumption of renewable sources alongside railways and guarantees a sustainable power supply in the case of grid disturbances and failures, e.g., voltage unbalance, harmonic and violent fluctuation, power outage, and extreme events in the wake of natural disasters and extreme weather. This approach also helps facilitate the development of the next generation TPSSs for enhanced flexibility and sustainability. Then, based on a comparative analysis of different resilient TPSSs, a brief outlook of the future trend is given. Finally, it is concluded that resilient TPSS provides a universal solution for both renewable energy integration and high-quality power supply against grid disturbances and failures.