Dynamic analysis and control design of a tension leg platform floating wind turbine system

Abstract

In this report it is intended to investigate potential controller improvements for an experimental wind turbine mounted on a TLP floating platform. Floating wind turbines are a novelty in the wind sector and as such, they require further research to improve their reliability and performance. It is already known that controllers designed for bottom-fixed structures can induce unwanted responses in the floating ones, for example negative damping. With this in mind and through numerical simulations, this report intends to find weak points in the controller currently in use in the mentioned turbine, and upgrade it for the floating turbine. In order to achieve this, several approaches are taken, including undermining the stability principle (leg tension), testing different environmental conditions, and tuning the controller. Despite this, the only relevant and realistic degradation in performance was found in the controller switching process between partial load and full operational modes. The floating wind turbine proved to have a robust performance even though it is fitted with a controller for bottom-fixed turbines.