LSTM-NN Yaw Control of Wind Turbines Based on Upstream Wind Information

Abstract

Based on wind lidar, a novel yaw control scheme was designed that utilizes forecast wind information. The new scheme can reduce the power loss caused by the lag of accurate measurement data in the traditional yaw control strategy. A theoretical analysis of the power loss caused by the traditional wind measurement inherent error and the wind direction based traditional yaw control strategy was conducted. The yaw angle error and yaw stop/start frequency in an actual wind field were statistically analyzed, and a novel Long Short Term-Neural Network (LSTM-NN) yaw control strategy based on wind lidar information was proposed. An accurate forecast of the wind direction could reduce the power loss caused by the inherent yaw misalignment, while an accurate forecast of wind speed could increase the stop/start frequency in the medium speed section within the partial load range and reduce the frequency in the low speed section within the partial load range. Thus, the power captured could be increased by 3.5% under certain wind conditions without increasing the yaw duty. Based on a simple wind evolution model and a novel yaw control strategy, the validity of the yaw control strategy was verified in a FAST/Simulink simulation model.

XE112-2000 Wind Turbine Yaw Strategy With Adaptive Yaw Speed Using DEL Look-Up Table

“…The yaw system needs to adjust the nacelle position to follow the change of the wind direction until the allowable error range is reached. The power loss caused by yaw misalignment is as follows [26]:…”

“…The lower the wind speed, the more frequent the wind direction changes; on the contrary, the higher the wind speed, the weaker the turbulence effect and the more stable the wind direction. Since industrial wind turbines generally do not consider the differences of wind speed characteristics in different wind speed ranges, but adopt the same yaw control logic, the performance of the wind turbine yaw system in different wind speed ranges is quite different [26]. Taylor's frozen turbulence theory assumes that the turbulence measured upstream reaches the rotor unchanged [28].…”

A 2.5MW Wind Turbine TL-EMPC Yaw Strategy Based on Ideal Wind Measurement By LiDAR

“…TYC generally starts yaw execution when the yaw error threshold reaches a certain set value [9]. The wind direction and nacelle position sensors measure the yaw error and nacelle position respectively.…”

“…Eloss is the power loss caused by yaw misalignment when the wind turbine does not yaw in a sampling period, Dbear is the equivalent damage rate of the yaw bearing during the yaw alignment process in a sampling period. Eloss is shown in (9), it should be noted that the yaw alignment is assumed to be completed in an instant, so the state of yaw misalignment continues a whole sampling period. er ( , )= ( , )…”

“…The common wind turbine yaw controller in the industry usually adopts a simple control method of yaw operation when the yaw error angle reaches a certain threshold, in order to pursue stability and reliability [9]. During this period, improved control methods based on angle thresholds appeared.…”