Estimation of rotor-effective wind speed from turbine-mounted LiDAR for real time applications

摘要

One of the major issues regarding development of wind energy is to reduce the energy production costs. Advanced control techniques are one of the levers to optimize performances of wind turbines. Wind turbine control can be improved through the use of a turbine-mounted light detection and ranging (LIDAR) device, which provide a reliable measure of he wind speed ahead of the rotor plan. Thus, these remote sensors give an advance notice of the approaching wind field and avoid sensing the wind in the close, highly disturbed, vicinity of the rotor plan (as performed by the nacelle-mounted cups). Therefore, many recent control strategies use the knowledge of the incoming wind for blade pitch control design (through model predictive control or feedforward control) to reduce significantly mechanical loads on the structure. Due to optical properties of such device, several error sources deteriorate the measured signal, thus, one of the major challenge is to enhance quality of the measured wind speed. Classical estimation strategies consist to delay the Lidar output by a time depending on the LIDAR orientation and mean wind speed usually justified by the Taylor frozen hypothesis. Then to recover the longitudinal speed, a scaling is applied to remove the influence of the projection of the wind vector over the Lidar beam. Our approach is to design real time filter that also takes a wind model, the LIDAR dynamics and the wind field into account. The implementation aspects of the proposed solution in industrial context is also studied to provide an easy to implement filter.