A Feedback Control Loop Optimisation Methodology for Floating Offshore Wind Turbines

Abstract

Wind turbines usually present several feedback control loops to improve or counteract some specific performance or behaviour of the system. It is common to find these multiple feedback control loops in Floating Offshore Wind Turbines where the system perferformance is highly influenced by the platform dynamics. This is the case of the Aerodynamic Platform Stabiliser and Wave Rejection feedback control loops which are complementaries to the conventional generator speed PI control loop when it is working in an above rated wind speed region. The multiple feedback control loops sometimes can be tedious to manually improve the initial tuning. Therefore, this article presents a novel optimisation methodology based on the Monte Carlo method to automatically improve the manually tuned multiple feedback control loops. Damage Equivalent Loads are quantified for minimising the cost function and automatically update the control parameters. The preliminary results presented here show the potential of this novel optimisation methodology to improve the mechanical fatigue loads of the desired components whereas maintaining the overall performance of the wind turbine system. This methodology provides a good balance between the computational complexity and result effectiveness. The study is carried out with the fully coupled non-linear NREL 5-MW wind turbine model mounted on the ITI Energy’s barge and the FASTv8 code.

TMD stroke limiting influence on barge-type floating wind turbines

“…The approaches taken in the current existing literature cover a wide range of areas of specialization, depending mainly on the objectives to be achieved (Pimenta et al, 2020). The general goal has been to provide a robust and maximized energy production (Olondriz et al, 2019;Rubio et al, 2019;Sierra-García and Santos, 2020a;Sierra and Santos, 2021). More specifically, the application of structural control to offshore wind turbines has been a topic of interest the last years (Sierra-García and Santos, 2020b;Park et al, 2019;Zuo et al, 2020).…”

Optimal Control of Hybrid Systems and Renewable Energies

“…The overall control problem is a nonlinear optimization problem which involves discrete and continuous variables, and is characterized by a model predictive controller, and a fuzzy algorithm is used to select the adequate operation mode. Wind turbines are instead considered in [2], and particular attention is focused on floating offshore wind turbines (FOWT). A novel optimization methodology, based on the Monte Carlo method, is developed for the manually tuned FOWT feedback controllers to improve the system performance minimizing a cost function.…”

Analysis of the Effects of the Location of Passive Control Devices on the Platform of a Floating Wind Turbine

“…The floating offshore wind technology is currently under development, with some prototypes or small floating farms already being installed. The floating wind turbines are powerful, but strongly non-linear and complex, systems [6], with important engineering problems to face, such as the transport of electricity to large distances by underground cables, the effects of the power control strategies on the stability and efficiency of the turbine [7][8][9], vibrations in the structure due to strong loads from wind, waves, currents, ice, [10], mooring lines [11], etc. This implies, on the one hand, great structural wear and fatigue, and the necessity of using more long-lasting, and possibly more expensive materials.…”