Abstract: Techniques for determining the presence of ice at a wind farm with a number of wind turbines. The controller receives a current ambient temperature of the wind farm. The controller also receives a measured current wind speed from wind speed sensors of the wind turbines. The controller also receives an estimated current wind speed of each of the wind turbines that is based on measured performance parameters of the associated wind turbine. The controller determines a current wind speed difference between the measured current wind speed and the estimated current wind speed for each of the wind turbines, and determines a current delta distribution based on the current wind speed differences. The controller also determines whether an ice event has occurred, the determination being in dependence on the current ambient temperature and in dependence on the current delta distribution, and then outputs an outcome of the ice event determination.

Abstract: Techniques for determining the presence of ice at a wind farm with a number of wind turbines. The controller receives a current ambient temperature of the wind farm. The controller also receives a measured current wind speed from wind speed sensors of the wind turbines. The controller also receives an estimated current wind speed of each of the wind turbines that is based on measured performance parameters of the associated wind turbine. The controller determines a current wind speed difference between the measured current wind speed and the estimated current wind speed for each of the wind turbines, and determines a current delta distribution based on the current wind speed differences. The controller also determines whether an ice event has occurred, the determination being in dependence on the current ambient temperature and in dependence on the current delta distribution, and then outputs an outcome of the ice event determination.

Abstract: A method of estimating a parameter relating to an upgrade of a wind turbine software includes toggling the wind turbine alternatingly between two modes, where the upgrade is implemented in one but not the other. Data is collected during toggling and divided into pairs of data parts, one from each mode. The data from the two modes is ordered separately and a quantile-to-quantile comparison is made.

Abstract: A method of estimating a parameter relating to an upgrade of a wind turbine software, the method comprising toggling the wind turbine alternatingly between two modes, where the upgrade is implemented in one but not the other. Data is collected during toggling and divided into pairs of data parts, one from each mode. The data from the two modes is ordered separately and a quantile-to-quantile comparison is made.