Wind turbine rotor control system
AssigneeNorth Wind Power Company, Inc.
InventorsClint Coleman, Hugh D. Currin
Life of this patent
Estimating the term…
Abstract
In a pitch control system for a wind turbine, a mechanical control system changes pitch angle of the rotor blades collectively in response to blade pitch moment. The control system is designed to be used with a downwind constant speed two-bladed horizontal axis teetering hub wind turbine. Pitch placement controls torque for a synchronous alternator connected to the electrical power grid. The pitch control system is manually lockable from the ground in run or shutdown modes. An automatic shutdown mode provides fullfeathering for protection from large amplitude vibrations or loss of the electrical grid.
Claims16
A constant speed wind turbine of the type comprising
- a tower-mounted free yawing carriage having vane means for aligning said carriage with the wind,
- a drive shaft defining a substantially horizontal rotor axis mounted for rotation in said carriage, and
- a wind-powered electrical generator operatively coupled to one end of said drive shaft having electrical terminals adapted to be connected to an electrical power grid, wherein the improvement comprises
- a rotor with variable pitch blades drivingly coupled coaxially to the other end of said drive shaft, and
- mechanical control means connected between said rotor and said carriage for establishing the pitch angle of said rotor blades collectively as a direct predetermined function of the blade pitch moment.
A downwind horizontal axis two bladed wind turbine of the type comprising a free yawing carriage having vane means for aligning said carriage with the wind, a drive shaft defining a substantially horizontal rotor axis mounted for rotation in said carriage and a wind-driven electrical generator operatively coupled to one end of said drive shaft, wherein the improvement comprises
- a downwind rotor assembly including a rotor teeter hub assembly with an inner teeter shaft member affixed to said drive shaft for rotation therewith and having a pair of aligned opposite radial arms defining a teeter axis, an outer teeter hub resiliently privotally mounted on said radial arms for limited teetering action on said teeter axis and carrying a pair of space parallel blade mounting hinges extending in opposite directions defining parallel pitch axes transverse to and displaced from said teeter axis in a plane nominally normal to drive shaft,
- a pair of rotor blades having inboard blade roots connected respectively to said blade mounting hinges, and
- elastic control means for establishing the pitch angle of said rotor blades as a function of the blade pitch moment.
Dependencies are inferred from the claim text.