Theoretical foundations for optimal control of floating offshore wind farms
department or school: Applied Science, Faculty of
department or school: Mechanical Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Cherom Kheirabadi, Ali
issued: 2021-05-17T17:17:42Z
issued: 2020
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Due to a phenomenon termed the wake effect, wind turbines that are placed in close proximity within wind farms interact aerodynamically. In short, each turbine generates a wake within which wind speeds are reduced, and these wakes overlap with the rotors of machines located downstream. This interaction diminishes power production in wind farms by up to 60%. Using a process referred to as wind farm control, individual wind turbines may be operated in a manner that increases power production from the collective. This thesis investigates the potential of a wind farm control strategy named yaw and induction-based turbine repositioning (YITuR) that is specifically compatible with floating offshore wind farms. Since floating platforms are anchored to the seabed using slack mooring line cables, each turbine may be repositioned in real-time using the aerodynamic forces exerted on its rotor. By relocating floating platforms accordingly, the overlap area between the wakes generated by upstream turbines and the rotors of downstream machines may be reduced; leading to an increase in wind farm efficiency. The potential of YITuR is assessed through several steps. First, a steady-state model of floating offshore wind farms is constructed and stationary optimization studies are carried out to determine the potential of YITuR under idealized steady wind conditions. Major findings from this study are that wind farm efficiency may increase by more than 40% using YITuR over traditional wind farm operation; however, these benefits are strongly influenced by mooring system designs. Second, a dynamic floating wind farm model is developed to evaluate the performance of real-time control systems. Third, due to the non-convexity of the YITuR control problem, novel distributed economic model predictive control (DEMPC) theory is developed to guarantee power maximization. Existing DEMPC algorithms do not offer such a guarantee in the presence of non-convex objective functions. Finally, the DEMP…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/76830
note: Theoretical Foundations for Optimal Control of FloatingOffshore Wind FarmsbyAli Cherom KheirabadiB.Eng., Dalhousie University, 2014M.A.Sc., Dalhousie University, 2016A THESIS SUBMITTED IN PARTIAL FULFILLMENTOF THE REQUIREMENTS FOR THE DEGREE OFDoctor of PhilosophyinTHE FACULTY OF GRADUATE AND POSTDOCTORALSTUDIES(Mechanical Engineering)The University of British Columbia(Vancouver)December 2020© Ali Cherom Kheirabadi, 2020The following individuals certify that they have read, and recommend to the Fac-ulty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled:Theoretical Foundations for Optimal Control of Floating Offshore WindFarmssubmitted by Ali Cherom Kheirabadi in partial fulfillment of the requirementsfor the degree of Doctor of Philosophy in Mechanical Engineering.Examining Committee:Ryozo Nagamune, Mechanical EngineeringSupervisorRajeev Jaiman, Mechanical EngineeringSupervisory Committee MemberGuy Dumont, Electrical EngineeringUniversity ExaminerMartin Ordonez, Electrical EngineeringUniversity ExaminerJan-Willem van Wingerden, Mechanical, Maritime, and Materials Engineering,Delft University of Technology, The NetherlandsExternal ExaminerAdditional Supervisory Committee Members:Anasavarapu Srikantha Phani, Mechanical EngineeringSupervisory Committee MemberBhushan Gopaluni, Chemical EngineeringSupervisory Committee MemberiiAbstractDue to a phenomenon termed the wake effect, wind turbines that are placed inclose proximity within wind farms interact aerodynamically. In short, each turbinegenerates a wake within which wind speeds are reduced, and these wakes overlapwith the rotors of machines located downstream. This interaction diminishes powerproduction in wind farms by up to 60 %. Using a process referred to as wind farmcontrol, individual wind turbines may be operated in a manner that increases powerproduction from the collective.This thesis investigates the potential of a wind farm control strategy namedyaw and induction-based turbine reposit…
has type: Thesis/Dissertation
date issued: 2021-05
is shown at: 10.14288/1.0395318
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/76830