Electric railway traction. VII. Electromagnetic interference in traction systems

This article describes some classic problems of interference in electric railway traction systems together with mitigation and modelling techniques. This article describes some practical noise problems in traction systems, with emissions spanning the complete frequency spectrum. The production of low-frequency (LF) noise from conductive and inductive coupling of currents and fields flowing in the traction system is described in terms of simple circuit and field models. Radio frequency (RF) noise is usually assessed by practical measurement, for which the current state of the art is reviewed. The article is concluded by a summary of the effect of European Community EMI limits.