Overvoltages Induced in the Supplying Line by an Electric Railway Vehicle

The paper focuses on a railway traction system. A railway vehicle, driven by a.c. three-phase asynchronous motors supplied through inverters from a single phase transformer, is connected to it. A brief description of the single phase a.c. (50 Hz, 25 kV) driving system is provided. The traction substation consists in down step voltage transformers supplied from the power system. The single phase traction system, when connected to the three-phase supplying system, introduces non-symmetries and current harmonics. A 50 km line segment from a simple supplying line was considered for simulation of overvoltages at current harmonics. A correct design of the railway vehicle driving system must meet the requirements imposed by the standard EN 50388 relative to its connection to the supplying line. Practical validation concerning overvoltages is discussed.