TRACTION DRIVES AND CONVERTERS

This paper describes the electrical traction drives available for electric & diesel-electric locomotives, multiple-unit trains and light rail vehicles. It commences with a review of the function of traction converters and consideration of the available converter power electronic switching devices. Then chopper and rectifier commutator motor drives are considered, followed by AC induction & synchronous motor drives with DC-fed voltage- and current-source inverters and the AC-fed four-quadrant converter. Finally, diesel-electric drives with generators, alternators, DC motors and AC induction motors are described. Examples are given of each drive within a mainly European and North American context. The focus of the paper is on generic drive properties and utilisation under the various types of traction power supply rather than the detailed operation of traction machines and converters.