Fuzzy Airflow-Based Active Structural Control of Integrated Oscillating Water Columns for the Enhancement of Floating Offshore Wind Turbine Stabilization

Abstract

This paper presents the modeling and stabilization of a floating offshore wind turbine (FOWT) using oscillating water columns (OWCs) as active structural control. The novel concept of this work is to design a new FOWT platform using the ITI Energy barge with incorporated OWCs at opposite sides of the tower, in order to alleviate the unwanted system oscillations. The OWCs provide the necessary opposing forces to the bending moment of the wind upon the tower and the waves upon the floating barge platform. However, the forces have to be synchronized with the tilting of the system which will be ensured by the proposed fuzzy airflow control strategy. Using the platform pitch angle, the fuzzy airflow control opens the valve of one side and closes the valve of the other side accordingly. Results of simulation in comparison with the standard FOWT and a PID-based airflow control show the efficiency of the fuzzy airflow control and its superiority to decrease the platform pitching and the top tower fore-aft displacement.