Operating a wind turbine generator (WTG) comprising a pitch control system, the operation comprising: a) operating the WTG in a normal mode while the WTG is connected to an external grid; b) controlling the pitch angle of the blades using a normal pitch control mode while the WTG is operating in the normal mode; c) detecting a grid loss; d) operating the WTG in a standby mode during the grid loss; and e) controlling the pitch angle of the blades in dependence on a monitored speed parameter of the WTG using a standby pitch control mode different to the normal pitch control mode while the WTG is operating in the standby mode, wherein the standby pitch control mode is less responsive than the normal pitch control mode such that the power consumption of the pitch control system is reduced when the WTG is operating in the standby mode.

A method of operating a windfarm connected to an electric grid via a point of injection for injecting power from the windfarm to the electric grid, the windfarm including at least two generating units and a windfarm controller, the method comprising: measuring 302 voltage and/or frequency characteristics of an electrical signal of the electric grid at the point of injection, communicating 304 to at least two generating units of the at least two generating units of the windfarm at least one control signal based at least in part on the measured voltage and/or frequency characteristics of the electrical signal of the electric grid at the point of injection, the at least one control signal being indicative of a grid situation at the point of injection; controlling 306 the at least two generating units of the at least two generating units of the windfarm at least in part based on the communicated at least one control signal.

The present invention relates to a method for controlling a wind power plant, WPP, comprising a plurality of wind turbine generators, WTGs, connected to an electrical grid, the method comprising: setting a plant power reference (Ptotal) according to an electrical value of the electrical grid; determining an inertia delta power reference (IRdeltaP) required for the WPP to meet a power demand in response to a change in the electrical value; adding the inertia delta power reference and the plant power reference (Ptotal) to form a power reference (Ptotalref); deriving an overboost reference (PrefOB) as the difference between the power reference (Ptotalref) and an available power value; dispatching the power reference (Ptotalref) to each wind turbine generator; dispatching the overboost reference (PrefOB) to each wind turbine generator. The invention also relates to a wind power plant control system and a wind power plant comprising a control system.

The present invention relates to a wind turbine comprising an internal power supply grid for distributing power to a number of power consuming units of the wind turbine, the wind turbine further comprising a power backup system connected to the internal power supply grid for supplying power to said internal power supply grid during a grid fault, wherein the power backup system comprises a power storage module providing a total backup voltage that falls within a nominal voltage range of the internal power supply grid of the wind turbine.

A method for operating a wind turbine comprises capturing an actual value of a fed-in power (P.sub.act) and determining a power deviation based on the captured actual value of the fed-in power (P.sub.act). A signal value is set for a correction of a setpoint value for the rotor blade pitch angle when one of the power deviation exceeds a predetermined maximum value and the power deviation exceeds a maximum gradient threshold value over a specified period of time. The signal value is cleared when one of the power deviation falls below a predetermined minimum value and a grid voltage value is located in a predetermined band around a specified target voltage value. A correction value (dβ/dt*) is determined for the setpoint value of the rotor blade pitch angle depending on the power deviation and applied to a rotor blade pitch control when the signal value is set.

Various embodiments distributively control a wind park having a plurality of wind turbines. Each wind turbine controlled by its own turbine controller. Each turbine controller determines power production capability of its dedicated wind turbine. The power production capability of the single wind turbine is communicated with a plurality of other turbine controllers in the wind park. A consensus power distribution schedule to distribute power to a power grid is determined using votes from each turbine controller in the wind park. Energy is discharged from each wind turbine to a power grid according to the power distribution schedule. When one wind turbine fails, a new power distribution schedule is determined using votes from each remaining turbine controller and energy is discharged from each wind turbine to the power grid according to the new power distribution schedule.

The present invention relates to operation of a wind turbine using a power storage unit, such as a rechargeable battery, to power a group of power consuming units during grid loss. The wind turbine comprises a number of power consuming units being grouped into at least a first group and a second group, a first electrical converter for connecting the generator to the electrical grid, and a second electrical converter for connecting the electrical generator to the power storage unit. Upon detecting an occurrence of the grid loss, the generator is operated to ensure sufficient power of the power storage unit to operate the first group of power consuming units.

A method of operating a wind turbine comprising a generator in the event of a voltage dip is disclosed. The method comprises detecting an end of the voltage dip, determining an acceleration of a rotor of the generator, and increasing a torque of the generator when the end of the voltage dip is detected according to a selected torque profile. The selected torque profile is selected from a plurality predetermined torque profiles, wherein the predetermined torque profiles describe torque as a function of time. The selected torque profile is selected based on the determined acceleration of the rotor of the generator. Also provided are wind turbines configured for such methods.

A wind turbine system comprising a nacelle mounted on a tower, a rotor having a plurality of blades and a boundary layer control system configured to control airflow through blade surface openings in each of the blades. The wind turbine system includes a control system configured to: monitor an operational speed parameter of the wind turbine, and activate the boundary layer control system if it is determined that the operational speed parameter exceeds a predetermined speed parameter threshold; monitor tower motion and to activate the boundary layer control system based on a determination of excessive tower motion; monitor for a wind turbine shutdown condition, activate the boundary layer control system if it is determined that the shutdown condition has been identified; monitor the aerodynamic loads on the blades, and activate the boundary layer control system based on a determination of excessive blade loads.

A method for controlling an electricity distribution grid having a nominal grid voltage, in particular in a critical grid situation, wherein a grid control center is provided for controlling the electricity distribution grid and the electricity distribution grid has at least one control region that comprises a plurality of mutually geographically separate wind farms, comprising the steps of: querying power outputs available from the wind farms, in particular on the basis of a weather forecast; defining a control node within the control region, in particular on the basis of the queried available power out-puts, preferably performed by the grid operator; combining a number of wind farms at the calculated control node to form a wind power plant on the basis of the queried available power outputs and/or a probability distribution of the available power output; controlling the wind power plant, in particular through the grid control center, by way of a wind power plant control unit, such that a required voltage quality and/or frequency stability and/or uninterrupted availability is provided in the control region.