REFLECTIONS ON THE FUTURE OF ELECTRIC TRACTION

A brief survey of the options available for electric traction, with descriptions of controlled rectifier/d.c. motor; controlled rectifier/inverter/asynchronous motors and controlled rectifier/inverter/synchronous motors. The synchronous motor is seen as the preferred present solution but future improvements in power semiconductors will allow the asynchronous motor to be an alternative. The ability of three phase motors to undertake a wide variety of duties is an important advantage and a more flexible approach to the operation of freight trains is forseen. Mechanical aspects are mentioned such as bogie design (monomotor and body motor/cardan) and motor surface speed.