Inverter drive system for a battery car

Since an electronic inverter is not far removed from the ‘chopper’ modulated dc voltage controller, it has bean suggested that the dc motor be replaced by an ac machine in a battery vehicle. The advantage of using a more robust and cheaper motor hat to be weighed against an increase in the complexity and cost of the additional electronic equipment. It may also be possible to achieve a better motor characteristic with respect to the requirements of the drive. A system is described which employs a synchronous motor driven by a transistorized inverter. The experimental results of the combination show a promising torque-speed characteristic with a large starting torque provided armature reaction is reduced. The inverter is arranged to incorporate voltage control so that the motor may be operated at maximum flux per pole over its entire speed range. The results show that it is necessary to control voltage and internal angle to retain the advantages of the system.