Abstract: A method of operating a wind turbine. The wind turbine is operated over an operating period in accordance with a control strategy. A sensor signal is received over the operating period from a sensor measuring an operational parameter of the turbine. A model is used to obtain a modelled fatigue value based on the sensor signal. The modelled fatigue value provides an estimate of fatigue loading applied to a component of the turbine over the operating period. The control strategy is modified based on the modelled fatigue value.

Abstract: A method for controlling a wind energy farm is disclosed. A wake state of the wind energy farm is determined, including determining wake chains defining wake relationships among the wind turbines of the wind farm under the current wind conditions. For at least one of the wind turbines of the wind energy farm, a lifetime usage is estimated, based on an accumulated load measure for the wind turbine. In the case that the estimated lifetime usage is below a predefined lifetime usage limit, the wind turbine is operated in an overrated state, while monitoring wake effects at each of the wind turbines. In the case that a downstream wind turbine detects wake effects above a predefined wake threshold level, at least one wind turbine having an upstream wake relationship with the downstream wind turbine is requested to decrease the generated wake, e.g. by decreasing power production.

Abstract: A method for planning repowering of a wind energy plant is disclosed. The wind energy plant is positioned at a site and comprises a plurality of original wind turbines arranged at distributed positions within the site. Historical data related to the original wind turbines is retrieved. The historical data is collected over a previous time period and during operation of the original wind turbines. Meteorological conditions at the site of the wind energy plant are estimated based on the retrieved historical data. The repowering of the wind energy plant is planned based on the estimated meteorological data, including planning replacement of the original wind turbines by replacement wind turbines to be positioned at the positions of the original wind turbines.

Abstract: A method of controlling a wind turbine is provided, comprising identifying an out-of-vertical load acting in a first direction on the wind turbine. A direction of a wind load acting on the wind turbine is determined. If there is a degree of alignment between the direction of the wind load and the first direction, the wind turbine is controlled to reduce the wind load.

Abstract: A method of controlling a wind turbine for the avoidance of edgewise vibrations. The method comprises the steps of determining a whirling mode frequency of a rotor blade of the wind turbine; determining a rotational frequency of the rotor blade corresponding to the speed of the rotor blade; determining a threshold value for the whirling mode frequency based on the rotational frequency; and, reducing the speed of the rotor blade if the whirling mode frequency substantially equals or is less than the threshold value.

Abstract: A control system and method of control are disclosed. A model predictive control, MPC, unit is configured to determine a control signal for controlling an operation of the wind turbine based at least in part on a cost function comprising a wear cost relating to one or more types of wear of the winding turbine, and a corresponding cost weighting, which defines a relative weighting of the wear cost in the cost function. A weighting determination unit is configured to receive a reference signal comprising a target wear, receive a feedback signal comprising a wear measure of the wind turbine, and determine, based at least in part on a difference between the target wear and the wear measure, a weighting adjustment for at least part of the cost weighting of the cost function. The MPC unit then sets the cost weighting based at least in part on the weighting adjustment.

Abstract: A method of controlling a wind turbine for the avoidance of edgewise vibrations. The method includes the steps of determining a whirling mode frequency of a rotor blade of the wind turbine; determining an avoidance zone based on the whirling mode frequency, the avoidance zone being a rotor speed range; receiving a rotor speed setpoint; and either adjusting the rotor speed to a value outside the rotor speed range if the rotor speed setpoint is within the rotor speed range or adjusting the rotor speed to a value corresponding to the rotor speed setpoint if the rotor speed setpoint is outside the rotor speed range.

Abstract: The present disclosure relates to controlling an operation of a wind turbine. A first plurality of extreme load measures indicative of extreme loads experienced by at least part of the wind turbine during the first period of time are determined and a load probability characteristic is then determined based on a statistical analysis of the distribution of the first plurality of extreme load measures. A control strategy for controlling the operation of the wind turbine is then modified based at least in part on a comparison of the load probability characteristic and a design load limit and the wind turbine is then subsequently controlled in accordance with the modified control strategy for a second period of time.

Abstract: A method of operating a wind turbine. The wind turbine is operated over an operating period in accordance with a control strategy. A sensor signal is received over the operating period from a sensor measuring an operational parameter of the turbine. A model is used to obtain a modelled fatigue value based on the sensor signal. The modelled fatigue value provides an estimate of fatigue loading applied to a component of the turbine over the operating period. The control strategy is modified based on the modelled fatigue value.

Abstract: A method for controlling a wind energy farm is disclosed. A wake state of the wind energy farm is determined, including determining wake chains defining wake relationships among the wind turbines of the wind farm under the current wind conditions. For at least one of the wind turbines of the wind energy farm, a lifetime usage is estimated, based on an accumulated load measure for the wind turbine. In the case that the estimated lifetime usage is below a predefined lifetime usage limit, the wind turbine is operated in an overrated state, while monitoring wake effects at each of the wind turbines. In the case that a downstream wind turbine detects wake effects above a predefined wake threshold level, at least one wind turbine having an upstream wake relationship with the downstream wind turbine is requested to decrease the generated wake, e.g. by decreasing power production.

Abstract: A method of operating a wind turbine having a rotor. Sensor data is received from one or more sensors of the wind turbine and maximum load values are obtained on the basis of the sensor data. The maximum load values are indicative of maximum loads acting on a component of the wind turbine such as a rotor blade. An estimated extreme load value, such as a 50-year return load, is obtained on the basis of the maximum load values and compared with a reference value. A maximum thrust limit is set on the basis of the comparison, and the wind turbine is operated in accordance with the maximum thrust limit so that a wind thrust force acting on the rotor does not exceed the maximum thrust limit.

Abstract: A method of controlling a wind turbine for the avoidance of edgewise vibrations. The method comprises the steps of determining a whirling mode frequency of a rotor blade of the wind turbine; determining a rotational frequency of the rotor blade corresponding to the speed of the rotor blade; determining a threshold value for the whirling mode frequency based on the rotational frequency; and, reducing the speed of the rotor blade if the whirling mode frequency substantially equals or is less than the threshold value.

Abstract: A method of controlling a wind turbine for the avoidance of edgewise vibrations. The method comprises determining a whirling mode frequency of a rotor blade of the wind turbine; determining an avoidance zone based on the whirling mode frequency, the avoidance zone being a rotor speed range; receiving a rotor speed setpoint; and either adjusting the rotor speed to a value outside the rotor speed range if the rotor speed setpoint is within the rotor speed range or adjusting the rotor speed to a value corresponding to the rotor speed setpoint if the rotor speed setpoint is outside the rotor speed range.

Abstract: A method of operating a wind turbine having a rotor. Sensor data is received from one or more sensors of the wind turbine and maximum load values are obtained on the basis of the sensor data. The maximum load values are indicative of maximum loads acting on a component of the wind turbine such as a rotor blade. An estimated extreme load value, such as a 50-year return load, is obtained on the basis of the maximum load values and compared with a reference value. A maximum thrust limit is set on the basis of the comparison, and the wind turbine is operated in accordance with the maximum thrust limit so that a wind thrust force acting on the rotor does not exceed the maximum thrust limit.

Abstract: A control system and method of control are disclosed. A model predictive control, MPC, unit is configured to determine a control signal for controlling an operation of the wind turbine based at least in part on a cost function comprising a wear cost relating to one or more types of wear of the winding turbine, and a corresponding cost weighting, which defines a relative weighting of the wear cost in the cost function. A weighting determination unit is configured to receive a reference signal comprising a target wear, receive a feedback signal comprising a wear measure of the wind turbine, and determine, based at least in part on a difference between the target wear and the wear measure, a weighting adjustment for at least part of the cost weighting of the cost function. The MPC unit then sets the cost weighting based at least in part on the weighting adjustment.

Abstract: The invention concerns a method and corresponding apparatus of transferring a piece of cloth from a pair of spreader clamps to a conveyor via a transverse boom, where the piece of cloth is first suspended and straightened between the spreader clamps, then delivered to the transverse boom, and subsequently delivered from the transverse boom to the conveyor. Apart from that, a straightening of the fore edge of the piece of cloth is performed, seen in the direction of conveyance of the conveyor, after its delivery from the clamps to the transverse boom has been initiated, but before it is delivered to the conveyor.

Abstract: By supplying a dentist's unit with joint made supports in the shape of arms (5, 7, 13), as carriers of respectively a bracket table (9) and a lamp (16), built in actuators can be programmed for adjustment of the supports. Furthermore, signal transmitters in the shape of light transmitters (17) can be mounted to the underside of the bracket table (9) and the lamp (16) for visual display of desired data for the treatment, in form of the patient's condition or instrumental data for display (19) onto the patient (21).

Abstract: The present disclosure relates to a rotatable tube rack holder for a tube rack rotator device, comprising: one or more plate(s) extending radially from an axis of rotation; one or more compartment(s) for tightly holding one or more tube rack(s) configured to hold a plurality of tubes, said compartment(s) is/are attached to at least one side of said plate(s); and one locking mechanism for each of said compartment and configured such that when said tube rack(s) holding a plurality of said tubes is/are placed inside said compartment, said tubes are restricted from moving in a direction perpendicular to said plate.