SNCF relations with the power supplies

EDF, the public utility national grid in France, requires its customers to observe rules so that unacceptable phenomena will not be generated on the high voltage network, the aim being to provide power to its adjacent customers under good conditions and without interference. These rules or technical conditions for connection are based on standards for electromagnetic compatibility such as IEC Standard 1000.2. Here the author describes how SNCF´s traction power system, in respect of the power supplier, and from the standpoint of interference, represents a railway load fed with 25 kV 50 Hz which can be characterised electrically as follows: a voltage unbalance on the three-phase network due to the single-phase load; a rate of voltage harmonics due to the return on the primary network of traction current harmonics; and a reactive power to be supplied