The application of DC grids to enhance the operation of 25 kV, 50 Hz railway systems

Supplying 25 kV, 50 Hz railway systems is a challenging task due to the load characteristics of those systems. Hence, several approaches are developed to improve their grid integration with the static frequency converter based substations. However, this supply system can be further refined by the application of a dc grid. Hence, this paper presents and discusses one possible approach to enhance the supply of 25 kV, 50 Hz railway systems by applying a dc grid.