Method for controlling a wind turbine and corresponding wind turbine
AssigneeREpower Systems AG
InventorMatthias Schubert
Life of this patent
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Abstract
Reduction in power output or rotor speed of a wind turbine above a defined limit value, the reduction not being implemented based on the measured wind speed, but on an input value which on one hand is easily detected physically and by control technology and on the other hand is a good indicator of mechanical stresses on the wind turbine. The invention uses the rotor-blade angle as the input value in a manner that starting at the limit value, the reduction in power output or in rotor speed is adjusted as a function of the rotor-blade angle.
Claims15
A method, utilizing feedback control with a feedback loop, with which to regulate a wind turbine that can generate a nominal power output, and being fitted with a rotor including at least one rotor blade configured at an adjustable blade angle relative to said rotor, wherein the wind turbine is subjected to varying wind speeds, with the load on the turbine being less than the load at the turbine's nominal power-output due to low wind speeds (lower partial-load range), or the load is kept in a permissible range due to adjustment of the turbine at high wind speeds (upper partial-load range), the method comprising the steps of:
- within a nominal power-output range, namely the power output range between a nominal wind speed at which the wind turbine output for the first time corresponds to the turbine's nominal power output and the maximum wind speed at which the turbine may be operating when delivering nominal power, which range follows operation within the lower partial-load range, operating the rotor at a substantially constant nominal rotor speed at which the wind turbine reaches its nominal power output at the nominal wind speed, until reaching a defined limit value;
- and
- after having crossed said limit value due to increasing wind speeds, operating the rotor within an upper partial-load range at a reduced rotor speed that is less than the rotor speed at which the wind turbine is able to deliver nominal power output, and
- wherein upon reaching the limit value, the rotor speed and, through a predetermined setpoint procedure, the setpoint rotor speed of a feedback loop are adjusted as a function of the rotor-blade angle.
A wind turbine that can generate a nominal power output and utilizing feedback control with a feedback loop, fitted with a rotor, comprising at least one rotor blade which is mounted on this rotor at an adjustable angle to it,
- wherein the wind turbine is subjected to varying wind speeds, with the load on the turbine being less than the load at the turbine's nominal power-output due to low wind speeds (lower-partial load range), or the load is kept in a permissible range due to adjustment of the turbine at high wind speeds (upper partial-load range), wherein the wind turbine within a nominal power-output range, namely the power output range between a nominal wind speed at which the wind turbine output for the first time corresponds to the nominal power output and the maximum wind speed at which the turbine may be operating when delivering nominal power, which range follows operation with the lower partial-load range, is operated at a substantially constant nominal rotor speed at which the wind turbine reaches its nominal power output at the nominal wind speed, until reaching a defined limit value and,
- after having crossed said limit value due to increasing wind speeds, is operated, within an upper partial-load range, at a reduced rotor speed that is less than the rotor speed at which the wind turbine is able to deliver nominal power output,
- wherein the turbine comprises a controller, the controller adjusting, upon reaching the limit value, the rotor speed and, through a predetermined setpoint procedure, the set-point rotor speed of a feedback loop, as a function of the rotor-blade angle.
Dependencies are inferred from the claim text.