Patent ID: 8296036

Claim:
An electric power management system for a vehicle, the electric power management system comprising: a power plant configured to generate electrical power and to supply a voltage to a power bus; a battery interconnected with the power bus, the battery configured to be charged from current generated by the power plant and supplied from the power plant to the battery via the power bus; a propeller drive unit interconnected with the power bus, and drawing power from the power plant via the power bus to cause movement of the vehicle; and a controller configured to direct the power management system in a plurality of distinct modes of operation, each distinct mode of operation controlling the propeller drive unit in a different manner, wherein the controller is configured to maintain bus voltage within a range defined by a maximum and minimum voltage while bus current remains approximately at a set point, wherein a first distinct mode of operation is a slow throttle mode and a second distinct mode of operation is a fast throttle mode; in the slow throttle mode, the flow of power is substantially only from the power plant and into the propeller drive unit and the battery; and in the fast throttle mode, the flow of power is from the battery and the power plant and into the propeller drive unit, and an increase in propeller drive unit speed that is requested is initially powered generally entirely by the battery, such that in the fast throttle mode, the propeller drive unit speed is not limited by a present level of power being generated by the power plant.