Session: 09-01-12 Wind Energy: System Optimization 1

Paper Number: 126010

126010 - Mooring Optimization of Floating Offshore Wind Turbines Using Genetic Algorithm 

Most global wind resources are found in water depths exceeding 60 meters, where using bottom-mounted structures is challenging and costly. Thus, increased the studies on floating offshore wind turbine (FOWT) solutions characterized by complex dynamics between the floating structures and turbines. Nowadays, one key challenge is designing optimum mooring arrangements for large-scale FOWT.

A meta-heuristic solution is recommended to solve a complex optimization problem, such as the mooring arrangement of a floating wind turbine. Among these, the Evolutionary Algorithms (EA) use mechanisms inspired by biological evolution. Genetic Algorithm (GA) is a multi-objective search and optimization algorithm based on the concept of Darwin’s theory of evolution, and it belongs to the class of Evolutionary Algorithms. It combines the idea of survival of the fittest with randomized information exchange.

Based on the literature, multi-objective optimization algorithms, such as the GA, are commonly used with hydrostatic and frequency-domain models, which are less accurate than a time-domain model for optimization purposes of FOWT.

This work addresses the optimization of the mooring system of a FOWT using time-domain simulations in OpenFAST. An in-house code is developed to handle calculations on OpenFAST and apply GA to find the optimal mooring arrangements for specific design variables meeting predefined multi-objectives, respecting all specific constraints for the FOWT. Finally, the optimized arrangements are checked against Ultimate Limit State (ULS) and Accidental Limit State (ALS), performed for the mooring system in damaged condition.

The developed optimization process is applied to the UMaine VolturnUS-S semisubmersible platform to maximize power quality and minimize the costs of the lines.

Presenting Author: Milad Shadman Federal University of Rio de Janeiro

Presenting Author Biography: Visiting Professor of the Ocean Engineering Department at COPPE / Federal University of Rio de Janeiro (UFRJ). D.Sc. in Ocean Engineering from COPPE / UFRJ (2017). Post-doctorate at COPPE / UFRJ (2017-2020). Working in the field of offshore renewable energy systems. Member of the COPPE’s Offshore Renewable Energy Group (GERO). Director at Pan-American Marine Energy Association (PAMEC.Energy). Coordinator of the Brazilian committee of the Marine Renewable Energy and member of the Brazilian committee of wind energy of ABNT. Member of the Technical Committee of the Offshore Wind and Ocean Renewable Energy of the Brazilian Society of Naval Engineering (SOBENA). His main research areas include design and analysis of offshore renewable energy systems including wave energy converters, floating offshore wind turbines, thermal gradient converters, offshore solar, hybrid system of offshore wind-wave and wind-solar, offshore renewable-powered desalination, and hydrogen production form offshore wind.

Authors:

Lucas Machado Federal University of Rio de Janeiro
Milad Shadman Federal University of Rio de Janeiro
Mojtaba Amiri Federal University of Rio de Janeiro
Segen Estefen Federal University of Rio de Janeiro