A Control Approach on Hybrid Floating Offshore Wind Turbines for Platform and Generated Power Oscillations Reduction at Below-rated Wind Speed

Abstract

This paper presents the use of four oscillating water columns integrated into the platform of a barge-type floating offshore wind turbine. A control strategy has been proposed to decrease the system’s oscillations and generated power fluctuations by adequately controlling the opening of the airflow valves. The switching time for below-rated wind speed has been calculated using the platform’s pitch response amplitude operator. The blades’ pitch has been adjusted to harness the maximum energy at below-rated wind speed and a constant torque method has been employed for the generator. A comparative study has been carried out between uncontrolled traditional barge-type and controlled oscillating water columns-based barge floating offshore wind turbine to determine the performance of the control technique. The findings demonstrate that the suggested control approach can effectively decrease both the oscillations in the system’s states and the fluctuations in the generated power. The results show a 26.6% fluctuation reduction in the generated power for the controlled OWCs-based barge platform, compared with the standard barge platform.