A traction system for a train, the traction system having: plural transformers for stepping down a voltage level of AC electric power provided from an overhead wire; and plural converter units for supply of electric power to motors of the train, each converter unit including an AC/DC convertor for converting the stepped down AC electric power provided by one of the transformers to DC electric power and an inverter for converting the DC electric power provided by the AC/DC convertor to multiphase AC electric power, wherein the AC/DC converters are configured to use pulse width modulation to convert the stepped down AC electric power on the basis of respective pulse signals which each have the same switching frequency but are phase shifted from each other to substantially cancel out second order harmonic noise from the pulse signals, characterised by: plural first switches which are closable to respectively connect high voltage sides of the transformers to the overhead wire, the closing of each first switch provoking an inrush current into the respective transformer; wherein the traction system further has a controller that is configured to control the timing of the closing of the first switches such that the first switches are closed in sequence with a first predetermined time interval between closures; and wherein the controller is further configured to control the timing of the start of power conversion using pulse width modulation by each of the AC/DC converters such that the starts are simultaneous and after the first switches have closed. plural transformers for stepping down a voltage level of AC electric power provided from an overhead wire; and plural converter units for supply of electric power to motors of the train, each converter unit including an AC/DC convertor for converting the stepped down AC electric power provided by one of the transformers to DC electric power and an inverter for converting the DC electric power provided by the AC/DC convertor to multiphase AC electric power, wherein the AC/DC converters are configured to use pulse width modulation to convert the stepped down AC electric power on the basis of respective pulse signals which each have the same switching frequency but are phase shifted from each other to substantially cancel out second order harmonic noise from the pulse signals, characterised by: plural first switches which are closable to respectively connect high voltage sides of the transformers to the overhead wire, the closing of each first switch provoking an inrush current into the respective transformer; wherein the traction system further has a controller that is configured to control the timing of the closing of the first switches such that the first switches are closed in sequence with a first predetermined time interval between closures; and wherein the controller is further configured to control the timing of the start of power conversion using pulse width modulation by each of the AC/DC converters such that the starts are simultaneous and after the first switches have closed. plural first switches which are closable to respectively connect high voltage sides of the transformers to the overhead wire, the closing of each first switch provoking an inrush current into the respective transformer; wherein the traction system further has a controller that is configured to control the timing of the closing of the first switches such that the first switches are closed in sequence with a first predetermined time interval between closures; and wherein the controller is further configured to control the timing of the start of power conversion using pulse width modulation by each of the AC/DC converters such that the starts are simultaneous and after the first switches have closed.