Use of power semiconductors to control locomotive traction motors in the French national railways

The application of semiconductor rectifiers and thyristors in the control of power to ac, dc, and diesel powered locomotives in the French National Railways is presented. A total of 260 locomotives have been equipped with 60 000 semiconductor rectifiers since 1959. The failure rate of these rectifiers has been 0.12 percent or 1.35 percent for every million kilometers traveled. Four locomotives have been equipped with thyristor control circuits and it is anticipated that all future single-phase ac powered locomotives will use thyristors.