Hierarchical energy management of multi-train railway transport system with energy storages

Railway transport systems are complex technical systems that consume significant amounts of energy and are suitable for advanced energy management approaches to make them more proactive participants in the next generation electrical smart grids. In the considered smart railway system, each train is controlled to achieve minimum travel costs while maintaining the timetable and passengers comfort. Meanwhile, the cost of electricity can be quite different in time, depending whether it is sourced from another train in braking, local energy storages or from the electrical power grid. The higher-level railway transport coordination system is introduced here for trains coordination with respect to external grid conditions, routes conditions, timetable requirements and current position on the route. This work is focused on the problem of train driving through the area supplied by a single power supply station that comprises a local microgrid with energy storage components. A concept of hierarchical decomposition for coordination of microgrid energy management and on-route train energy consumption with the main goal of maximising the economic benefit is presented. It is shown that the concept is extendable on several trains driving through the same power supply area.