Method for operating or controlling a wind turbine and method for providing primary control power by means of wind turbines
View Patent ↗A method for operating at least one wind turbine with a rotor and an electric generator coupled to the rotor for delivering electrical power into an energy distribution system with the aid of a control device ensures that the wind turbine operates within its operating range. The wind turbine is controlled in response to the change of a system operating parameter and for a period of time, in such a manner that a higher power is fed into the system than belongs to the operating range of the steady-state operation. The same conditions also apply to a method for providing control power or primary control power for an electric energy generator and distributor system to which a multiplicity of power stations including wind turbines is connected, and to a wind turbine.
1. A method for operating a generating system comprising at least one wind turbine with a rotor and an electric generator coupled to the rotor for delivering electrical power into an energy distribution system with a control device which ensures that the wind turbine operates within its operating range, comprising:
a) operating the wind turbine in a non-throttled mode that corresponds to a best usable characteristic of the wind turbine;
b) detecting an unpredicted change in an operating parameter of the energy distribution system;
c) reacting to the unpredicted change by feeding a higher amount of power into the energy distribution system, the higher amount of power being greater than is permitted by wind conditions by an excessive amount, the excessive amount of power being taken from the kinetic energy of the rotor; and
d) returning to the non-throttled mode after the feeding of the excessive amount of power is completed.
2. The method of claim 1 , further comprising determining a minimum rotational speed and automatically ending the feeding of the excessive amount of power when the minimum speed is reached.
3. The method of claim 2 , the reacting to the unpredicted change occurs in response to an occurrence of a limit value or fault signal, and wherein the limit value or fault signal is generated either locally at the wind turbine or at a distance from the wind turbine in the energy distribution system.
4. The method of claim 1 or 2 , wherein a multiplicity of wind turbines is driven by a multiplicity of different signals and wherein the different signals can be generated by a central system control.
5. The method of claim 1 or 2 , wherein a system frequency, a system voltage or a rate of change of the system frequency or system voltage is used as the system operating parameter.
6. The method of claim 1 or 2 , wherein the the reacting to the unpredicted change occurs in response to at a frequency drop within a range of below 0.2 Hz or with a decrease of above approx. 0.05 Hz in 1 second.
7. The method of claim 1 or 2 , comprising selecting a time of approx. 0.05 to 60 seconds as a period of time during which the higher power is fed into the energy distribution system.
8. The method of claim 1 or 2 , further comprising continuously delivering the signals to the wind turbines on the basis of measurements, statistics or empirical data.
9. The method of claim 1 or 2 , comprising, when the speed is reduced by increased power delivery, correcting the blade pitch angle in such a manner to enable optimum power to be taken from the wind for the prevailing wind and speed conditions.