롤 회전하는 3축 초음파 풍속계를 활용한 풍향 풍속 측정기법(II)

Abstract

In a previous study, a technique for measuring wind speed and direction by using a roll-rotating three-axis ultrasonic anemometer was proposed and verified by wind tunnel tests. In the tests, instead of a roll sensor, roll angle was trimmed to make no up flow in the transformed wind speeds. Verification was done in point of the residual error of the rotation effect treatment. In this study, roll angle was measured from the roll motor encoder and the transformed wind speed and direction on the test section axis were compared with the ones provided to the test section. As a result, up to yaw 20° at a wind speed of 12 m/sec or over, the RMS error of wind speed was within the double of the ultrasonic anemometer error. But at yaw 30°, it was over the double of the ultrasonic anemometer error. Regardless of wind speed, at yaw 20° and 30°, the direction error was within the double of the ultrasonic anemometer error. But at yaw 10° or less, it was within the error of the ultrasonic anemometer itself. This is a very favorable characteristic to be used for wind turbine yaw control.