Interaction between power supply and rolling stock

The catenary, made up of a set of electrical conductors, is located just over five meters above the ground. From the traction operator's point of view, it provides the energy required by the traction unit. From an EMC point of view, it behaves like a distributed constant line made up of inductances and capacitances. The inductance is of the order of a millihenry per kilometer, and the capacitance of the order of 15 to 25 nF per kilometer.

Fixed electrical traction systems (FETS) must supply traction energy to any point on the railway line, while complying with quality criteria. The traction unit must consume this energy as efficiently as possible, without polluting it. These two subsystems are therefore intimately interdependent. Various physical phenomena have been observed, some of them of such magnitude that they can lead to disruptions in railway operations,...