Elektrisitetsforsyningssystem for banestrom

An electricity supply system for traction comprises a supply conductor C, a return conductor R e.g. a rail, a positive feeder conductor P and a negative feeder conductor N, all four of said conductors being connected to a winding of each of a plurality of autotransformers 1 provided at intervals along said conductors. A current booster transformer 2 having one winding connected into the positive feeder conductor P and another winding connected into the negative feeder conductor N, and at least one further current booster transformer 3a, 3b having one winding connected into the supply conductor C and another winding connected into the return conductor R are provided in the or each interval between the autotransformers.