Abstract: The present disclosure relates to a system for determining at least one blade state parameter of a wind turbine blade, wherein the system is configured to: obtain blade data relating to the wind turbine blade from a sensor system associated with the wind turbine blade; compare at least one reference model of at least a portion of the wind turbine blade with the blade data; identify a reference model in dependence on the comparison; and determine at least one blade state parameter in dependence on the identified reference model. The blade data may take the form of an image, for example a 3-dimensional measurement such as a point cloud representing at least a portion of the blade.

Abstract: A method for monitoring a wind turbine comprises monitoring an acoustic signal and/or a vibrational signal within a tower of the wind turbine, analyzing the signal to identify one or more predetermined characteristic indicative of an event within the tower, recognizing the event has occurred based on the predetermined characteristic and generating an output based on the recognized event. The one or more predetermined characteristic being at least one of: an amplitude of the signal, a duration of the signal, a shape of the signal, one or more frequencies present in the signal and an energy of the signal.

Abstract: Controlling a wind turbine comprising a wind sensor, a number of pitch-adjustable rotor blades, a yawing system, and a control system for yawing the wind turbine rotor relative to the wind and for changing the pitch of the rotor blades. A wind parameter is measured by the wind sensor, and is indicative of the wind speed and/or the wind direction relative to the wind turbine. At least a first and a second set of wind correction parameters for different production modes of the wind turbine are obtained. The production mode of the wind turbine is then determined, which may be one of at least normal operation or non-production, and the measured wind parameter is then adjusted as a function of the set of wind correction parameters corresponding to the production mode at the time of adjusting. Hereby a more precise wind parameter is obtained which can be used in the controlling of the turbine.

Abstract: The invention relates to control of a wind turbine comprising a plurality of multi-axial accelerometers mounted at different positions in the nacelle and/or in a top portion of the tower. The position and orientation of each accelerometer as mounted is obtained, accelerations in at least two different directions by each accelerometer are measured during operation of the wind turbine. From a number of predetermined mode shapes for the movement of the wind turbine is then determined an absolute position of at least one of the accelerometers during operation of the wind turbine based on the measured accelerations, the mount position and orientation of each accelerometer and the pre-determined mode shapes. Hereby a more precise absolute position during operation is obtained which can be used in the controlling of the turbine.

Abstract: A yaw sensor for a wind turbine is described. The yaw sensor comprises a rotary switch, configured to be coupled to a yaw drive gearbox of a wind turbine nacelle, the rotary switch being operable to activate and deactivate an electrical contact in dependence on an amount of yaw rotation of the nacelle relative to a start position. The electrical contact is active at a plurality of first yaw rotation ranges with respect to the start position, and inactive at a plurality of second yaw rotation ranges with respect to the start position, the first and second yaw rotation ranges being interleaved, at least some of the first yaw rotation ranges having different lengths from each other and/or at least some of the second yaw rotation ranges having different lengths from each other. The electrical contact generates an electrical signal when active.

Abstract: Embodiments herein describe a system used to estimate the presence of water on a sensor. A parameter maintains a wind sensor temperature. The parameter can be tracked and evaluated to indicate a likelihood of water on the sensor. Alternatively, or in combination with the above, the sensor is adjusted intentionally or deactivated and reactivated to track a parameter response which is then used to indicate a likelihood of water on the sensor.

Abstract: According to an embodiment of the present invention there is provided an apparatus for controlling a sub-system of a wind turbine. The apparatus comprises a cooling system comprising first and second heat exchangers, and a fluid circuit arranged to enable a coolant to flow between the first and second heat exchangers; and a processor. The processor is configured to: monitor one or more operational parameters of the cooling system; determine an icing risk based on the one or more operational parameters; and generate a control signal for output to the wind turbine sub-system in dependence on the determined icing risk.

Abstract: The invention relates to a method of controlling a wind turbine comprising a wind direction sensor, a yawing system, and a control system for yawing the wind turbine rotor relative to the wind. The method comprises obtaining an estimate for a wind power parameter as a function of a relative wind direction, where the wind power parameter is determined as one of a power, a torque, a blade load, or a blade pitch angle of the wind turbine. At time intervals, a data set is established comprising a wind power parameter and a wind direction parameter as measured by the wind direction sensor. Over time a group of data sets is then obtained for a number of pre-defined wind direction intervals, and a wind direction offset is determined for each interval by comparing the average wind power parameter for that interval with the estimate of the wind power parameter.

Abstract: A wind turbine includes at least one wind speed sensor, a number of pitch-adjustable rotor blades, and a control system for changing the pitch of the rotor blades and/or a generator torque. The the control system determines at time intervals an error parameter as the difference between an estimated wind speed and a measured wind speed as measured by the wind speed sensor. Then, based on a number of pre-defined wind speed intervals, a group of error parameters is obtained over time for each wind speed interval. For each wind speed interval and for each group of error parameters a wind speed offset is determined based on the average of the error parameters within the group which wind speed offsets are used in adjusting the measured wind speed.

Abstract: A method of determining torsional deformation in a drivetrain e.g. of a wind turbine. To provide a reliable and simple deformation assessment, the method comprises the step of generating a first signal representing first rotational speed of a low speed shaft, generating a second signal representing the second rotational speed of a high speed shaft, and determining torsional deformation based on changes in the ratio between the first and second signals.

Abstract: A method of detecting a fault mode of a sensor is provided. The sensor may be, for example, a bending moment sensor and may sense a bending moment of a blade on a wind turbine generator (WTG). The method includes comparing data output by a first sensor with reference data indicating what is expected to be output by the first sensor to produce a first comparison result and comparing data output by the first sensor with data output by a second sensor to produce a second comparison result. A determination of whether the first sensor has entered a fault mode is made based at least in part on the first and second comparison results.

Abstract: A wind turbine includes a wind direction sensor, a yawing system, and a control system for yawing the wind turbine rotor relative to the wind. The control system measures a wind direction parameter by the wind direction sensor Over time a group of data sets is obtained and a wind direction offset is determined from the group of data sets which is used to adjust the wind direction parameter. The adjusted wind direction parameter is then used in the controlling of the wind turbine.

Abstract: A control system for yawing a wind turbine rotor relative to the wind and for changing the pitch of rotor blades. A wind direction parameter is measured by a wind direction sensor. The wind direction is calibrated as a function of a predetermined offset parameter, and then adjusted as a function of a wind direction compensation parameter. The adjusted relative wind direction is then used in the determining of a control parameter of the wind turbine. The parameters for the calibration and adjustment of the relative wind direction are obtained from a set of data comprising the wind direction relative to the wind turbine over time and as measured by the wind direction sensor on the wind turbine and as measured by a second wind direction sensor.

Abstract: The invention relates to control of a wind turbine comprising a plurality of multi-axial accelerometers mounted at different positions in the nacelle and/or in a top portion of the tower. The position and orientation of each accelerometer as mounted is obtained, accelerations in at least two different directions by each accelerometer are measured during operation of the wind turbine. From a number of predetermined mode shapes for the movement of the wind turbine is then determined an absolute position of at least one of the accelerometers during operation of the wind turbine based on the measured accelerations, the mount position and orientation of each accelerometer and the pre-determined mode shapes. Hereby a more precise absolute position during operation is obtained which can be used in the controlling of the turbine.

Abstract: A yaw sensor for a wind turbine comprises a plurality of rotary switches, each configured to be coupled to a yaw drive gearbox of a wind turbine nacelle, the rotary switches each being operable to activate and deactivate respective associated electrical contacts in dependence on an amount of yaw rotation of the nacelle relative to a start position. Each electrical contact is active at a plurality of first yaw rotation ranges with respect to the start position, and inactive at a plurality of second yaw rotation ranges with respect to the start position, the first and second yaw rotation ranges being interleaved.

Abstract: Controlling a wind turbine comprising a wind direction sensor, a yawing system, and a control system for turning the wind turbine rotor relative to the wind. Over one or more time intervals a data set comprising a direction of the wind relative to the wind turbine as measured by the wind direction sensor and a wind power parameter determined as one of a power, a torque, or a blade load of the wind turbine are obtained. The data sets are sorted into a number of bins of different intervals of wind power parameter. For each power bin, a statistical representation of the wind power parameter as a function of the relative wind direction is determined and then used in estimating a wind direction offset corresponding to the relative wind direction where the wind power parameter attains a peak value. The relative wind direction is then adjusted as a function of the set of wind direction offsets to yield more accurate wind direction data which can be used in controlling the turbine.

Abstract: Method of controlling a wind turbine. A data set is obtained that includes a direction of the wind relative to the wind turbine and a pitch angle parameter representing a pitch angle of at least one of the wind turbine blades. Based on the obtained data sets, a statistical representation of the pitch angle parameter as a function of the relative wind direction is determined, which is then used in estimating a wind direction offset corresponding to the relative wind direction where the pitch angle parameter attains a maximum. The relative wind direction of the wind turbine is then adjusted as a function of the wind direction offset.

Abstract: The present disclosure relates to a control system for a wind turbine that is configured to: obtain a 3-dimensional image of at least a portion of a wind turbine blade; recognise a target feature of the wind turbine blade in the obtained image and identify the position of the target feature; and monitor the state of the wind turbine blade and/or control operation of at least one blade in dependence on the identified position of the feature.

Abstract: The present disclosure relates to a system for determining at least one blade state parameter of a wind turbine blade, wherein the system is configured to: obtain blade data relating to the wind turbine blade from a sensor system associated with the wind turbine blade; compare at least one reference model of at least a portion of the wind turbine blade with the blade data; identify a reference model in dependence on the comparison; and determine at least one blade state parameter in dependence on the identified reference model. The blade data may take the form of an image, for example a 3-dimensional measurement such as a point cloud representing at least a portion of the blade.

Abstract: A method of determining torsional deformation in a drivetrain e.g. of a wind turbine. To provide a reliable and simple deformation assessment, the method comprises the step of generating a first signal representing first rotational speed of a low speed shaft, generating a second signal representing the second rotational speed of a high speed shaft, and determining torsional deformation based on changes in the ratio between the first and second signals.