SYSTEM AND METHOD FOR DETERMINING THE WIND YAW MISALIGNMENT OF A HORIZONTAL AXIS ON-SHORE WIND TURBINE

摘要

This invention relates to system for determining the wind yaw misalignment of a horizontal axis on-shore wind turbine comprising the wind turbine, a lidar, a topographical station, an external computing unit and a telecommunication network connecting them. Said wind turbine further comprises two target points made of reflective materials placed on the external surface of the nacelle on its side facing the ground, such that be detected by the topographic station. The lidar is configured to determine wind direction angle in respect to the north and wind speed, the topographic station is configured to determine the geographical position and orientation of the pair of target points. The lidar and the topographical station communicate the values determined to the external computing unit.;The invention further relates to a method for determining the wind yaw misalignment of a horizontal axis on-shore wind turbine using the system of the invention. In the first step the wind direction angle in respect to the north, the wind speed and the geographical position and orientation of the pair of target points are determined and sent to the external computing unit. Then, in the second step, the external computing unit receives the values determined. In the third step, the external computing unit determines the angle of the geographical orientation of the nacelle in respect to the Geographical North. In the fourth step, the external computing unit applies a validation condition and a first compass rose condition and determines based on them an adjusted angle of the wind. Then, in the fourth step, the external computing unit averages the instant values of the adjusted angle of the wind direction and of the wind speed resulting the averaged angle of the wind direction and the averaged wind speed. Steps 6 and 7 of the method are carried only as long as the averaged wind speed v_is comprised within the predetermined interval of wind speeds v₁ - v₂. In step 6 of the method, the external computing unit determines the wind yaw misalignment σ of the turbine T in respect to the wind direction as a difference between the averaged angle of the wind direction and the angle of the orientation of the nacelle. In the last step of the method, at the expiry of the duration of the method, the external computing unit determines the averaged wind yaw misalignment of the turbine as an arithmetic mean of the plurality of values of the wind yaw misalignment during the duration of the method.;The invention further comprises a computer program for the external computing unit for carrying out the steps of the method as well as an external computing unit for carrying out the steps of the method.