Active heave compensation of floating wind turbine installation using a catamaran construction vessel. (January 2021) - Ren, Zhengru
Abstract: The application of floating wind turbines is limited by the high cost that increases with the water depth. Offshore installation and maintenance continue to consume a high percentage of the project budget. To improve the installation efficiency of the floating offshore wind turbine, a novel concept is proposed by the SFI MOVE project. Several wind turbine superstructure components are preassembled onshore and carried to the installation site by a catamaran construction vessel. Each assembly can then be installed using only one lift, and the concept is less sensitive to weather conditions. In this paper, a control algorithm of the proposed hydraulic active heave compensator system is developed using singular perturbation theory to cancel the relative motion between the spar top and gripped preassembly bottom. Closed-loop stability is proven, and the simulation results show that the installation efficiency is improved with an increase in the acceptable weather conditions. Highlights: Floating offshore wind turbine preassembly installation using a catamaran installation vessel. Hydraulic active heave compensator is developed to cancel the relative motion between the spar top and gripped preassembly bottom. Two sections are included in the trajectory planning module for the hydraulic cylinder. Closed-loop stability is proven with singular perturbation theory. More than 95% and 93% relative displacement and relative velocity are reduced, respectively, in most scenarios.