Extreme typhoon loads effect on the structural response of offshore meteorological mast and wind turbine

Recently, Taiwan started to evaluate the potential of wind energy production on its West coast. The concern was raised about employing existing solutions validated by experience for mild environment regions to Taiwan which is frequently subject to Typhoon. This study investigated the strength under typhoon condition of two offshore wind farm units: a meteorological mast supported by a monopile and a 3.6 MW wind turbine supported by a 4-leg jacket. Especially, two critical load cases were analyzed. First, the study provided a simplified approach to evaluate the wave run-up load on a monopile. The dynamic structure response of the meteorological mast evaluated through finite element analyses showed that large vibrations excited the tower after the slamming. In a second time, the study evaluated the extreme wind loads exerted on the blades of the parked wind turbine considering a blade pitch control fault. As a result, for a constant gust wind speed of 70 m/s, the loads at the nacelle increased tremendously by approximately 220% compared to the parked wind turbine without fault condition. ? Copyright 2016 by ASME.