The purpose of this invention is to simplify the train control by eliminating a switching section. In the alternating current feeding system, one sub-station of a plurality of sub-stations is provided with a first three-phase alternating current power source that has a first frequency; a transformer that is used for changing the three-phase alternating voltage from the first three-phase alternating current power source to a two-phase alternating voltage, and for connecting one of the one-phase output terminal of the two-phase output terminal to a single phase alternating current feeding electric wire; a first power converter that has an alternating current output terminal connected to M seat of the two-phase output terminal of the transformer; a second power converter that has an alternating current output terminal connected to T seat of the two-phase output terminal of the transformer; a direct current smoothing capacitor connected to a common direct current terminal of the first andsecond power converters; a compensation current control means for controlling a compensation current generated from the first and the second power converters; a second three-phase alternating currentpower source that has a second frequency; and a diode rectifier for converting the three-phase alternating current of the second three-phase alternating current power source to a direct current and feeding direct current power to the direct current smoothing capacitor.