Abstract: The invention relates to a method for controlling a wind turbine system, more particular for a controlled sliding strategy to lower loads on the yaw system by controlling mechanical brakes and motor brakes in the yaw drive actuators. When the yaw system being in the non-yawing operational state, and the mechanical brake(s) being in an engaged state, and the yaw controller determines or receives a signal indicative of a yaw moment, and if the signal indicative of a yaw moment is above a signal threshold, then the yaw controller sends a braking signal to the yaw drive actuators to enter the motors into the brake state to apply a braking torque.

Abstract: Aspects of the present invention relate to a method of controlling a renewable power plant comprising a plurality of renewable power generators electrically connected by a local network and configured to supply active power to a main network. The method comprises: in response to receiving a signal requesting substantially zero active power supply to the main network: categorizing a generator as power-supplying, and the remaining generators as power-consuming; operating the power-consuming generators to generate no active power and to have their auxiliary systems draw power from the local network; and operating the power-supplying generator to supply active power to the local network such that the plant supplies substantially zero active power to the main network.

Abstract: A method of providing safety configuration parameters for a wind turbine is provided. The method comprises receiving a safety configuration file at a location of the wind turbine, and comparing a turbine ID associated with the safety configuration file to a turbine ID of the wind turbine stored at the location of the wind turbine. A tamper check is performed on the safety configuration file to determine if data in the safety configuration file has been modified. If the turbine ID associated with the safety configuration file matches the turbine ID of the wind turbine, and if the tamper check determines that the data has not been modified, a safety configuration parameter associated with a safety system of the wind turbine is extracted from the file and stored.

Abstract: A wind turbine including yaw control comprising a controller receiving an input signal, and providing an output control signal to a yaw actuator. The input signal to the controller is based on: a first feedback signal that is indicative of the relative wind direction determined with respect to the wind turbine, wherein the first feedback signal is filtered with a first low pass filter; and a second feedback signal that is indicative of the activity of the yaw actuator. The control technique of the invention significantly improves the ability of a yaw system to maintain a zero degree yaw error during steady state wind conditions, or in other words to maintain an accurate heading of the nacelle pointing into the wind, as well as reducing the maximum yaw error experienced during yaw system activation.

Abstract: A wind turbine including yaw control comprising a controller receiving an input signal, and providing an output control signal to a yaw actuator. The input signal to the controller is based on: a first feedback signal that is indicative of the relative wind direction determined with respect to the wind turbine, wherein the first feedback signal is filtered with a first low pass filter; and a second feedback signal that is indicative of the activity of the yaw actuator. The control technique of the invention significantly improves the ability of a yaw system to maintain a zero degree yaw error during steady state wind conditions, or in other words to maintain an accurate heading of the nacelle pointing into the wind, as well as reducing the maximum yaw error experienced during yaw system activation.

Abstract: To efficiently nm a wind turbine in varying wind speeds, the wind turbine may be configured to switch between two different electrical configurations that offer different efficiencies depending on wind speed. For example, a star configuration may be preferred during low wind speeds while a delta configuration is preferred for high wind speeds. Before switching, the power output by the turbine's generator may be driven to zero. Doing so, however, removes load from the rotor blades which cause the rotor speed to increase. Instead, the rotor speed may be controlled such that the speed stays at or above the speed of the rotor immediately before the generator power is ramped down. Maintaining rotor speed at or slightly above the current speed while switching between electrical configurations may mitigate the torque change experienced by the turbine and reduce the likelihood of structural failure.

Abstract: A method and associated control arrangement are disclosed for controlling a de-rated power output of a wind turbine generator, where the wind turbine generator is associated with a predetermined power ramp rate upper limit and operating with a de-rated rotor speed. The method includes ramping the power output from an initial power level to a target power level during a ramping interval. During a first portion of the ramping interval, the power output is ramped at a first power ramp rate less than the power ramp rate upper limit. The method further includes ramping the rotor speed to a predetermined rotor speed value contemporaneously with ramping the power output during the first portion of the ramping interval. The first power ramp rate is determined such that a difference between the power output and the target power level is monotonically decreasing during the entirety of the ramping interval.

Abstract: A method and associated control arrangement are disclosed for controlling a de-rated power output of a wind turbine generator, where the wind turbine generator is associated with a predetermined power ramp rate upper limit and operating with a de-rated rotor speed. The method includes ramping the power output from an initial power level to a target power level during a ramping interval. During a first portion of the ramping interval, the power output is ramped at a first power ramp rate less than the power ramp rate upper limit. The method further includes ramping the rotor speed to a predetermined rotor speed value contemporaneously with ramping the power output during the first portion of the ramping interval. The first power ramp rate is determined such that a difference between the power output and the target power level is monotonically decreasing during the entirety of the ramping interval.

Abstract: To identify abnormal behavior in a turbine blade, a failure detection system generates a “fingerprint” for each blade on a turbine. The fingerprint may be a grouping a dynamic, physical characteristics of the blade such as its mass, strain ratio, damping ratio, and the like. While the turbine is operating, the failure detection system receives updated sensor information that is used to determine the current characteristics of the blade. If the current characteristics deviate from the characteristics in the blade's fingerprint, the failure detection system may compare the characteristics of the blade that deviates from the fingerprint to characteristics of another blade on the turbine. If the current characteristics of the blade are different from the characteristics of the other blade, the failure detection system may change the operational mode of the turbine such as disconnecting the turbine from the utility grid or stopping the rotor.

Abstract: The invention refers to a method for de-icing a blade of a wind turbine. The de-icing is carried out by means of stalling the wind turbine and at least to a position where enough turbulence is created to induce vibrations in the blade allowing ice to break off.

Abstract: To efficiently nm a wind turbine in varying wind speeds, the wind turbine may be configured to switch between two different electrical configurations that offer different efficiencies depending on wind speed. For example, a star configuration may be preferred during low wind speeds while a delta configuration is preferred for high wind speeds. Before switching, the power output by the turbine's generator may be driven to zero. Doing so, however, removes load from the rotor blades which cause the rotor speed to increase. Instead, the rotor speed may be controlled such that the speed stays at or above the speed of the rotor immediately before the generator power is ramped down. Maintaining rotor speed at or slightly above the current speed while switching between electrical configurations may mitigate the torque change experienced by the turbine and reduce the likelihood of structural failure.

Abstract: To identify abnormal behavior in a turbine blade, a failure detection system generates a “fingerprint” for each blade on a turbine. The fingerprint may be a grouping a dynamic, physical characteristics of the blade such as its mass, strain ratio, damping ratio, and the like. While the turbine is operating, the failure detection system receives updated sensor information that is used to determine the current characteristics of the blade. If the current characteristics deviate from the characteristics in the blade's fingerprint, the failure detection system may compare the characteristics of the blade that deviates from the fingerprint to characteristics of another blade on the turbine. If the current characteristics of the blade are different from the characteristics of the other blade, the failure detection system may change the operational mode of the turbine such as disconnecting the turbine from the utility grid or stopping the rotor.

Abstract: The invention refers to a method for de-icing a blade of a wind turbine. The de-icing is carried out by means of stalling the wind turbine and at least to a position where enough turbulence is created to induce vibrations in the blade allowing ice to break off.