Research and analysis of a flexible integrated development model of railway system and photovoltaic in China

Greening of the railway energy supply chain is an irreversible trend, and photovoltaics (PVs) provide the most suitable type of renewable energy to integrate with railways. The integration of variable and uncertain PV power generation with the dynamic loads on a railway increases the flexibility needed to maintain load-generation balance. A new evolutionary model of a railway energy supply system (RESS) for railway PV integration systems (RPISs) is proposed by constructing a three-in-one “traction-storage-information integrated station” (TSIIS). A flexibility evaluation approach is proposed to estimate the system flexibility of both the individual TSIIS and the banded featured microgrid group through energy storage capacity configuration and dynamic scheduling via a multileader multifollower Stackelberg game. Finally, the Lanzhou-Xinjiang Railway is taken as an example to calculate the emission reduction and flexibility. The results show that through application of the storage configuration and scheduling strategy to the TSIIS network, the flexibility index of the Lanzhou-Xinjiang Railway increased by 8.40%, which promoted a corresponding decrease in carbon dioxide emissions and increase in PV permeability. In addition, with the gradual construction of PV and energy storage systems, an RPIS can basically achieve self-consistent energy utilization, offering environmental benefits and strong flexibility.