Patent ID: 7635923
Filing Date: 2009-12-22
Classification: F03D,F05B,H02J,H02P,Y02B,Y02E,Y02P

Abstract:
1. In a wind-driven electrical generator comprised of a controller and a propeller coupled to a drive shaft, the propeller being comprised of a plurality of blades affixed to a central hub that rotates with the drive shaft and which houses at least one servo motor, the at least one servo motor being coupled to the controller and configured to rotate at least one propeller blade around a longitudinal axis of the propeller blade that extends outwardly from the central hub, the at least one servo motor controlling the blade's pitch under software control, a method of rotating the propeller when wind speed drops comprising the steps of: detecting a drive shaft deceleration; sending a first signal from the controller to the at least one servo motor, responsive to a detected drive shaft deceleration, the first signal causing the at least one servo motor to change the pitch of at least one of the plurality of propeller blades to reduce wind drag on the propeller; and responsive to the detected drive shaft deceleration, supplying rotational torque to the drive shaft from a motor mechanically coupled to the drive shaft in order to maintain drive shaft rotation.