Active control system for high speed windmills

A pump control system for high speed windmills comprising

• a piston pump, a wind driven shaft, a gear box connected to the wind driven shaft, a crank connected to the gear box, an adjustable oscillating lever means, first connecting means for connecting the crank to the lever means and second connecting means for connecting the oscillating lever means to the piston pump, an auxiliary pump connected to the oscillating lever means for pumping hydraulic fluid in response to movement of the first connecting means, accumulator means connected to the auxiliary pump for accumulating hydraulic fluid under pressure from the auxiliary pump, hydraulic cylinder connected to one of the connecting means for controlling the length of the oscillating lever means from zero to a maximum, first and second hydraulic supply lines connected to the hydraulic cylinder for driving a piston within the cylinder in a first direction to effectively lengthen the oscillating lever means and in a second opposite direction to effectively shorten the oscillating lever means to zero length, valve means connected to the hydraulic conduit and to the hdyraulic cylinder supply lines for selectively pressurizing one of the supply lines and exhausting the other of the supply lines, valve control means connected to the valve means for controlling operative condition of the vlave means and speed responsive means connected to the shaft means and to the valve control means for controlling the valve control means according to speed of the shaft.

In a windmill having a wind driven element operating a piston pump, a control system comprising:

• lever means interposed between said element and said pump for varying the length of stroke of the piston in said pump,
• control means, responsive to changes in the velocity of the wind driven element to operate said lever means to vary the length of stroke and hence the effective displacement of said pump in accordance with available wind energy, said control means comprising means connected to the wind driven element for sensing speed of the wind driven element and response means connected to the speed sensing means and to the lever means for changing the lever means to vary length of the stroke of the pump in response to the speed of the wind driven element, wherein the response means comprises an auxiliary pump and means connecting the auxiliary pump to the wind driven element, conduit means connected to the auxiliary pump, accumulator means connected to the conduit means for accumulating hydraulic pressure applied to the conduit means by the auxiliary pump, hydraulic cylinder means connected to the conduit means and to the lever means for changing the lever means in response to application of hydraulic fluid to the hydraulic cylinder means and valve means connected to the conduit means for controlling flow of fluid to and from the hydraulic cylinder means and valve controlling means connected to the speed sensing means for controlling the condition of the valve means in response to sensed speed of the wind driven element, and wherein the conduit means comprises a hydraulic pump output line connected to the auxiliary pump and to the accumulator and check valve means connected in the pump output line for permitting flow of hydraulic fluid from the auxiliary pump toward the accumulator and for preventing flow of hydraluic fluid from the accumulator toward the auxiliary pump, a pressure supply line connected to the accumulator for supplying hydraulic fluid under pressure to the valve means and first and second actuator lines connected to opposite ends of the hydraulic cylinder and wherein the valve means comprise first and second valve means for connecting the first and second actuator lines respectively to the pressure line and to the return line and respectively in response to changing position of the valve control means to connect one actuator line to the hydraulic pressure line and the other actuator line to a hydraulic pump return line.