AN OPTIMAL DC MOTOR/CONTROLLER CONFIGURATION

Optimal constructions for two motor/controller configurations are disclosed. The controller structure includes an H-bridge for controlling field current using synchronous-rectification of MOSFET devices, and a circuit for chopping the armature current using synchronous-rectification of MOSFET devices arranged in a half bridge. The controller may be configured with a series-wound or a separately excited DC traction motor. In the series-wound motor/controller configuration, the field and the armature current are separately controlled. In the separately excited motor/controller configuration, the field of the motor is preferably wound so that the rated field current is achieved at about 20% of the rated battery voltage. This provides a separately excited motor in which the field current can be boosted by a factor of 5 to achieve high start-up and low speed torques which match the torque outputs of a series-wound motor under similar operating conditions.