International audienceSince power electronics is used in railway traction, harmonic interactions between rolling stock and power supply installations have been observed. In the 25 kV-50 Hz French railway network, due to the traffic increasing, these problems can cause high traffic disturbances. To study and solve these problems, a systematic approach, based on simulation tools using a library of elementary models, is proposed. The first step is to develop a circuit modelling of railway power supply including all devices. Secondly, locomotive electrical models, including internal control loops, are inserted in the circuit and harmonic interactions can be analysed. Thanks to this method, the origin of voltage disturbances is more easily ident...