Operational Analysis of Traction Substations Cluster Continuous Co-Phase Traction Power Supply System with Photovoltaics and Energy Storage

The traction substations cluster continuous co-phase traction power supply system (TPSS) offers an effective solution for power grids with limited access position, enabling long-distance power supply, eliminating the neutral sections in the traditional AC 25kV TPSS, improving the direct utilization of regenerative braking energy, and increase the access flexibility for photovoltaic and energy storage. Firstly, various schemes for photovoltaic and energy storage access to the traction substation for the continuous co-phase TPSS are introduced. Then, a unified power flow calculation model for the continuous co-phase TPSS containing photovoltaic, energy storage, and co-phase power supply devices is developed. Additionally, the TPSS's operational characteristics are analyzed based on an actual urban rail transit line. The results show that the utilization rate of regenerative braking energy reaches 100% by the continuous co-phase TPSS. The photovoltaic and co-phase power supply devices can both improve the power supply capacity of the TPSS while suppressing three-phase voltage unbalance.