Electromagnetic Compatibility of the Railway System. Basis, Context, and Reference Documents

Running a rail convoy presupposes that each of its components (tramway, locomotive, towed equipment, railcar, TGV trainset, etc.) has a certain ability to integrate into the convoy (rolling stock subsystem), the railway infrastructure and, more generally, its environment. Conversely, other moving parts in circulation, the railway structure as a whole, and systems external to the railway domain must all respect the circulation of the convoy in question. In other words, putting together and operating a vehicle or a rail convoy requires compliance with the basic rules of electromagnetic compatibility (EMC) between sub-systems.

Ensuring EMC between subsystems is all the more important given that railroads involve large subsystems, that they make increasing use of electric traction, and that the power of traction units increases with towed loads and commercial speeds, and with increased traffic, particularly in urban areas.... Furthermore, electric traction requires static energy conversion equipment capable of switching on and off high currents at high voltages. This EMC issue concerns both electric mass transit in urban areas and railroads in general. The railway system has an international dimension, and the globalization of the industrial railway market is more topical than ever. Designers must therefore harmonize their products, taking into account the varying characteristics of different countries: power supply voltages and frequencies, safety equipment, mechanical gauges, operating modes, etc.

The railway sector is home to :

• harmonic currents directly linked to the operating frequencies of converters and the power supply network;

• intensity variations that generate magnetic fields;

• rapid voltage variations, which generate capacitive currents.

The railway sector also includes low-current installations used for control functions and information systems. These subsystems are sensitive to the influence of strong currents. The dimensions of each of these sub-systems are considerable: a few tens or hundreds of meters for the train itself, tens of kilometers for the power supply sub-system, as well as for the infrastructure in general, particularly the information system supports.

In this context, traction equipment is often seen as the main disrupter or "aggressor", while low-current equipment is generally regarded as the "victim".

This presentation, presented in two joint articles, will focus on compatibility specific to the railway sector, i.e. the interaction between the subsystems that make it up... It does not deal with EMC issues internal to each of the subsystems,...