Evaluation of half wave induction motor drive for use in passenger vehicles. Final report

This report describes research performed to devise and design a lower cost inverter-induction motor drive for electrical propulsion of passenger vehicles. A two-phase inverter-motor system is recommended. It is predicted to provide comparable vehicle performance, improved reliability and nearly a 10% cost advantage for a high production vehicle because of the reduction in total parts count, decreased total rating of the power semiconductor switches and somewhat simpler control hardware compared to the conventional three-phase bridge inverter-motor drive system. The major disadvantages of the two-phase inverter-motor drive are that the tow-phase motor is larger and more expensive than a three-phase machine, the design of snubbers for the power switches is difficult because motor lead and bifilar winding leakage inductances produce higher transient voltages, and the torque pulsations are relatively large because of the necessity to limit the inverter switching frequency to achieve high efficiency. An actuall model of the two-phase system must be constructed and evaluated. The most challenging engineering design task will be to design the inverter, motor and snubber circuits to minimize transient voltages with high system efficiency.