Modelling yaw-drive utilization for floating wind turbines in changing metocean conditions

Description

This paper investigates yaw-drive utilization for the IEA 15MW offshore reference wind turbine and the implications of moving from a bottom-fixed to floating platform sub- structure. The wind turbine is exposed to large wind direction changes based on wind measurements from the Østerild test center site. The wind samples contain only the slow- moving averages of the measured data, representing the main direction of the incoming wind, that the implemented yaw controller should track. By simulating the turbine response for 11 one hour wind samples, the yaw-utilization and resulting loads are in- vestigated for both fixed and floating substructure. As the transition to floating wind turbines adds six new degrees of freedom to the system, potential instabilities are accessed and mitigated as far as possible. The most significant differences in loads between the fixed and floating simulations are highlighted and the level of importance is discussed. The evaluation process of the yaw-drive utilization focuses on comparing the fixed and floating substructure simulations with the main parameters being mean yaw error and load statistics (mean, minimum and maximum) from relevant load channels. This study serves as a baseline for yaw-drive utilization of floating wind turbines, an area which has not yet been fully discovered. The simple, slow-moving winds implemented here are very useful for preliminary analysis of the functionality of the yaw-controller, however the addition of wind turbulence and waves are needed to obtain a greater understanding of the wind turbine response in changing metocean conditions.

Period	Jan 2023 → Jun 2023
Examinee	Mathias Valentin Hemmingsen
Examination held at	Department of Wind and Energy Systems
Degree of Recognition	National