The Evolution of Railway Power Supply Systems Toward Smart Microgrids: The concept of the energy hub and integration of distributed energy resources

In recent years, the achievement of sustainable energy systems has become one of the foremost challenges of experts around the world. In this context, the reduction of energy consumption while providing optimum power flow to the end users is a substantial challenge in various fields of generation, transmission, and distribution. Environmental concerns like global greenhouse gas emissions and other problems related to fossil fuels, together with deficiency of resources, are other significant aspects.