Session: 09-01-07 Wind Turbine Aerodynamics - 2

Paper Number: 80883

80883 - Structural Load Estimation of Downstream Wind Turbines in an Offshore Wind Farm 

In the design of offshore wind turbines, the focus has been mostly on the aero-hydro-servo-elastic coupling analysis of one single turbine. However, there have been studies of fixed offshore wind turbines showing that the wake meandering among turbines in offshore wind farms affects both the power generation and the structural loading of downstream wind turbines.

 

To investigate the structural loads of fixed offshore wind turbines placed downstream, FAST.Farm, a new medium-fidelity wind farm modeling tool developed by the National Renewable Energy Laboratory, is used in this study. FAST.Farm is based on the Dynamic Wake Meandering model which includes passive tracer modeling of wake meandering, but FAST.Farm tackles some limitations of the previous Dynamic Wake Meandering methods. Previous studies of FAST.Farm have shown the validation with high fidelity models for small wind farms.

 

In this study, three IEA Wind 15MW offshore reference wind turbines with monopile support structures, are placed at the distance of eight rotor diameters in the prevailing wind direction. FAST.Farm responses are compared to large eddy simulation software of SOWFA under different wind conditions and sea states. The outputs suggest that mean generator power, rotor speed, and blade pitch angle resulted from FAST.Farm, reasonably agree with SOWFA results for upstream and downstream turbines above rated wind speeds.The difference in structural loads of downstream turbines are discussed and applicable use of FAST.Farm simulation is suggested.

 

This study provides references for using FAST.Farm in large-scale offshore wind farm load analysis and monitoring as a trade-off between accurate simulation and computational cost in the future.

Presenting Author: Yiqing Xia Tokyo Electric Power Services Co., Ltd.

Authors:

Yiqing Xia Tokyo Electric Power Services Co., Ltd.
Yosuke Matsumoto Tokyo Electric Power Services Co., Ltd.
Iman Yousefi Tokyo Electric Power Services Co., Ltd.
Kazuyoshi Oouchi Tokyo Electric Power Services Co., Ltd.
Shunsuke Kaneko Tokyo Electric Power Services Co., Ltd.
Michio Nittouji Tokyo Electric Power Services Co., Ltd.
Kenji Fujii Tokyo Electric Power Services Co., Ltd.
Kaho Machida Tokyo Electric Power Services Co., Ltd.