후류에 의한 풍력터빈의 피로하중 특성

Abstract

The wake generated by a wind turbine has an effect on performance of a downstream wind turbine as well as mechanical loads, and therefore lifetime of the wind turbine. The wake effects also increases in offshore wind farms where the turbulence intensity is lower and wake is longer since there is less turbulence to mix the flow behind an upstream wind turbine. This paper examines the importance of the wake effects with respect to fatigue damage. In the same context, this paper also investigated characteristics of fatigue load at the blade root due to the wake effects and quantitatively analyzed its effects at operating condition of a 5MW tripod offshore wind turbine using Bladed 4.1 software. The aim of this study is to analyze the wake effects on calculated fatigue load on the wind turbine installed at a wind farm. The wake effects was studied the way the wake's center position move from the rotor center to the blade tip to the far-away position where the wake doesn't affect the wind turbine. When wake's center was located on the blade tip or the rotor center, damage equivalent fatigue load was higher than other positions. It was up to 10∼14% compared to those of non-wake case. Results of this study would be helpful to design wind turbines and wind farms to have lifetimes more than 20 years of the wind turbine.