Optimal Energy Dispatch of Energy Storage System as a Shared Infrastructure between DC Railway Network and DC Micro Grid

Urban railways and electric vehicles will be critical in achieving city sustainability. EV shows great potential for improving railway energy efficiency. At the same time, the integration of a Photovoltaic (PV) system and an Electric Vehicle (EV) charging system is a common method of utilizing renewable resources on-the-spot. An energy storage system (ESS) can work as a shared infrastructure to combine railway, PV, and EV into a DC micro-grid. In this paper, an energy dispatch model based on the structure of the DC micro-grid and the function of each component is built and solved with Mixed-integer linear programming (MILP). To investigate the model’s rationality and the effects of each part on the overall cost and operation pattern, three specific cases are tested. The global cost minimization that can be obtained by using EV and ESS to absorb the energy from PV and railway has been assessed. The utilization of ESS capacity can be promoted by the integration of EV charging demand and renewable energy.