풍력터빈 스피너에 설치된 3축 초음파풍속계의 회전측정기법을 활용한 풍향풍속 측정

Abstract

In previous studies, a measuring technique for wind direction and speed with a roll-rotating horizontal three-axis ultrasonic anemometer was proposed and verified by wind tunnel tests. In this study, it was applied to a 4.3 MW wind turbine that has a nacelle anemometer and a wind lidar. In subsonic flow, the upstream is affected by downstream blockage such as a spinner, wind turbine blades, and a nacelle. From a blockage effect study with CFD analysis, the measuring point of the ultrasonic anemometer was selected and blockage correction equations were derived. At the measuring point, the wind speed and wind direction relative to the wind turbine, the so-called yaw error, were measured by the proposed technique and corrected with the derived equations. As a result, the blockage correction reduced the deviation of yaw error but overcorrected wind speed. So, the proposed method may be efficient for wind turbine yaw control because it has smaller yaw error fluctuation than a nacelle anemometer and a wind lidar. Blockage correction with met mast tests instead of CFD would produce better results. Various environmental tests such as in rain, snow, and dust in wind would also be a prerequisite for actual utilization.