Proper selection of the traction drive system to meet the requirements of an electric passenger vehicle is of prime importance. Choice may be made among alternating current, direct current or combined systems.
Each approach can be implemented by utilizing various control techniques and power elements. For instance, an AC system may use an adjustable voltage inverter (AVI) or a pulse-width-modulated inverter (PWMI) for the power processor; and an induction motor or a synchronous motor for the rotating element. Similar alternatives exist for a DC system. The choice of a suitable manner of implementation must be based on information characterizing the various elements and tradeoffs matching them to the vehicle requirements.
This paper describes various AC and DC techniques, characterizes AVI, PWM and representative DC chopper power processors and examines their interface with a variety of motors such as series, shunt, induction, etc. A review of characteristics relating to electric car requirements is made in an attempt to orient the designer and user with information necessary for selection of drives.