# US 10,865,771 B2 · Control of a wind turbine having adjustable rotor blades > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,771 B2 - Document ID: US10865771B2 - Status: Granted - Kind: B2 - Application number: 15/775,727 - Filed: 2016-11-17 - Published: 2018-11-15 - Granted: 2020-12-15 - Earliest claimed: 2015-11-18 - Assignees: Wobben Properties GmbH - Applicants: Wobben Properties GmbH - Inventors: Andree Altmikus; Wolfgang De Boer; Ralf Messing - Web page: https://patentgrep.com/patent/US10865771B2 ## CPC - F03D 7/0224: {Adjusting blade pitch} - F03D 1/06: Rotors - F03D 7/024: {of individual blades} - F03D 7/026: {for starting-up} - F03D 17/00: Monitoring or testing of wind motors, e.g. diagnostics (testing during commissioning of wind motors F03D13/30) - F05B 2220/30: in turbines - F05B 2240/221: with horizontal axis - F05B 2260/74: by turning around an axis perpendicular the rotor centre line - F05B 2260/83: Testing, e.g. methods, components or tools therefor - F05B 2270/1033: Power (if explicitly mentioned) - F05B 2270/20: to optimise the performance of a machine - F05B 2270/309: Rate of change of parameters - F05B 2270/32: Wind speeds - F05B 2270/322: the detection or prediction of a wind gust - F05B 2270/327: Rotor or generator speeds - F05B 2270/331: Mechanical loads - F05B 2270/335: Output power or torque - Y02E 10/72: Wind turbines with rotation axis in wind direction - F03D: WIND MOTORS - F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A method for controlling a wind turbine having rotor blades with an adjustable blade angle, comprising the steps operating the wind turbine in a partial load mode for wind velocities up to a nominal wind velocity, wherein in the partial load mode, a fixed partial load angle is provided for the blade angle, operating the wind turbine in a full load mode for wind velocities above the nominal wind velocity, wherein in the full load mode the blade angle is enlarged with increasing wind velocity and has values above the partial load angle, and wherein in the partial load mode, starting from a predetermined operating state, the blade angle is reduced as compared with the partial load angle. ## Claims ### Claim 1 A method for controlling a wind turbine having rotor blades with adjustable blade angles, the method comprising: operating the wind turbine in a partial load mode for wind velocities up to a nominal wind velocity, wherein in the partial load mode: a first partial load angle is provided for the adjustable blade angle, and starting from a predetermined operating state, the adjustable blade angle is reduced as compared with the first partial load angle, and operating the wind turbine in a full load mode for wind velocities above the nominal wind velocity, wherein in the full load mode the adjustable blade angle is enlarged with increasing wind velocity and has values above the first partial load angle, wherein in the partial load mode, a power is set as a function of the rotational speed of a rotor of the wind turbine, and, starting from at least one of a predetermined rotational speed and a predetermined power, the adjustable blade angle is adjusted as compared with the first partial load angle, and wherein the adjustable blade angle is reset to the first partial load angle before the full load mode is reached, wherein sensors are provided to detect torsion of at least one of the rotor blades about its longitudinal axis, wherein the detected torsion is used as a criterion for adjusting the adjustable blade angle, and wherein the adjustable blade angle is adjusted to have a sharper rise as a value of the detected torsion increases. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein in the partial load mode, the adjustable blade angle is adjusted as compared with the first partial load angle as a function of torsion of the rotor blades about the blade longitudinal axis, a blade loading, or both. ### Claim 3 (depends on 2) The method as claimed in claim 2, wherein the adjustable blade angle is adjusted as the rotational speed rises or as the power rises as a function of the rotational speed or the power. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein the adjustable blade angle is reduced so highly as compared with the first partial load angle that the blade angle assumes a negative value. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein, as the wind velocity increases, the adjustable blade angle in the partial load mode initially has the first partial load angle in a lower range, in the partial load mode is reduced as compared with the first partial load angle in an upper range, and in the full load mode, is increased as compared with the first partial load angle. ### Claim 6 (depends on 5) The method as claimed in claim 5, wherein in the partial load mode, following the upper range, a third range is provided, wherein the third range follows the full load mode in that the adjustable blade angle is increased at least as far as the first partial load angle. ### Claim 7 (depends on 5) The method as claimed in claim 5, wherein the upper range in the partial load mode, the adjustable blade angle is reduced as a function of: the power, the rotational speed of the rotor of the wind turbine with a predetermined gradient, or a predetermined relationship of the power or rotational speed. ### Claim 8 (depends on 1) The method as claimed in claim 1, wherein in the partial load mode, the adjustable blade angle is adjusted as compared with the first partial load angle as a function of at least one property of the air. ### Claim 9 (depends on 8) The method as claimed in claim 8, wherein in the partial load mode, the adjustable blade angle is adjusted as compared with the first partial load angle as a function of the air density or of a wind gust. ### Claim 10 (depends on 1) The method as claimed in claim 1, wherein the wind turbine has a plurality of rotor blades, and each rotor blade is configured to be adjusted individually. ### Claim 11 (depends on 10) The method as claimed in claim 10, wherein the wind turbine has three rotor blades. ### Claim 12 (depends on 10) The method as claimed in claim 10, wherein each rotor blade is configured to be adjusted cyclically in rotation such that the individual blade angle or a blade angle set point comprises a basic angle that is the same for all the rotor blades and an additional angle provided individually for each rotor blade. ### Claim 13 (depends on 1) The method as claimed in claim 1, wherein a minimum blade angle is provided, wherein the minimum blade angle is smaller than the first partial load angle, and wherein the adjustable blade angle for each rotor blade is configured to be individually adjusted to the minimum blade angle. ### Claim 14 (depends on 1) A wind turbine, configured to perform a method as claimed in claim 1.