Abstract: A utility grid is provided, the utility grid including a centralized controller; an intermittent renewable energy source for generating electrical power; at least one further power generation system; and a local controller for controlling the total power output of the intermittent renewable energy source and the at least one further power generation system, wherein the centralized controller is connected with the local controller and adapted to request a desired total power output from the local controller.

Abstract: The invention relates to Method of operating a wind turbine, wherein rotor windings of an induction generator, which comprises stator coils coupled to a voltage grid, fed with rotor currents by a feed-in unit are driven by a rotor of the wind turbine; wherein the frequencies of the fed-in rotor currents are controlled depending on the rotor rotation frequency and the feed-in unit is electrically decoupled from the rotor windings in the case predetermined variations of the grid voltage amplitude and the rotor current feed-in is resumed after the decoupling caused by the variation of the grid voltage amplitude, when the currents generated in the rotor windings by the variation have declined to a predetermined value.

Abstract: A utility grid is provided, the utility grid comprising a centralized control means, an intermittent renewable energy source for generating electrical power: at least one further power generation system; and at least one local controller for controlling the total power output of said intermittent renewable energy source and said as least one further power generation system, wherein the centralized control means is connected with the at least one local controller and adapted to request a desired total power output from the local controller.

Abstract: The invention relates to Method of operating a wind turbine, wherein rotor windings of an induction generator, which comprises stator coils coupled to a voltage grid, fed with rotor currents by a feed-in unit are driven by a rotor of the wind turbine; wherein the frequencies of the fed-in rotor currents are controlled depending on the rotor rotation frequency and the feed-in unit is electrically decoupled from the rotor windings in the case predetermined variations of the grid voltage amplitude and the rotor current feed-in is resumed after the decoupling caused by the variation of the grid voltage amplitude, when the currents generated in the rotor windings by the variation have declined to a predetermined value.

Abstract: A method of operating a wind turbine, wherein the wind turbine may include rotor windings of an induction generator, which includes stator coils coupled to a voltage grid, fed with rotor currents by a feed-in unit are driven by a rotor of the wind turbine; wherein the frequencies of the fed-in rotor currents are controlled depending on the rotor rotation frequency and the feed-in unit is electrically decoupled from the rotor windings in the case predetermined variations of the grid voltage amplitude and the rotor current feed-in is resumed after the decoupling caused by the variation of the grid voltage amplitude, when the currents generated in the motor windings by the variation have declined to a predetermined value.

Abstract: The invention relates to Method of operating a wind turbine, wherein rotor windings of an induction generator, which comprises stator coils coupled to a voltage grid, fed with rotor currents by a feed-in unit are driven by a rotor of the wind turbine; wherein the frequencies of the fed-in rotor currents are controlled depending on the rotor rotation frequency and the feed-in unit is electrically decoupled from the rotor windings in the case predetermined variations of the grid voltage amplitude and the rotor current feed-in is resumed after the decoupling caused by the variation of the grid voltage amplitude, when the currents generated in the rotor windings by the variation have declined to a predetermined value.

Abstract: Two independent adjusting systems are recommended for each rotor blade (6) for blade angle adjustments of the rotor blades (6) of the rotor of a wind power plant, assuring full redundancy of the blade angle adjustment. By suitable control of the individual adjustment paths of the two adjustments systems, additional advantageous effects can be gained, such as good lubricant distribution and/or even load distribution over time (FIG. 1).

Abstract: Two independent adjusting systems are recommended for each rotor blade (6) for blade angle adjustment of the rotor blades (6) of the rotor of a wind power plant, assuring full redundancy of the blade angle adjustment. By suitable control of the individual adjustment paths of the two adjustment systems, additional advantageous effects can be gained, such as good lubricant distribution and/or even load distribution over time (FIG. 1).