| 摘要 |
<p>A control system (10) for an electric vehicle golf car having a shunt wound motor including an amarture coil (22) and a field coil (24). The system includes one MOSFET (34) connected in parallel across the armature coil, along with a freewheel diode (42), and another MOSFET (36) connected in series with the armature coil. When the motor is operating below its based speed, i.e., when the back EMF is below the power supply voltage, current flow can be induced by momentarily turning on the series MOSFET, shorting the armature coil. Current flow in the counterclockwise direction is thus initiated, at which point the series MOSFET is turned off, resulting in a large voltage spike across the motor, causing current flow back into the battery pack. By quickly turning the series MOSFET on and off, current flow can be maintained, and regenerative braking occurs at slow speeds.</p> |
