Author : Mehran Ahmadi
Publisher :
ISBN 13 :
Total Pages : 99 pages
Book Rating : 4.:/5 (879 download)
Book Synopsis Analysis and Study of Floating Offshore Wind Turbines by : Mehran Ahmadi
Download or read book Analysis and Study of Floating Offshore Wind Turbines written by Mehran Ahmadi and published by . This book was released on 2013 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Floating wind turbines offer a means to vastly expand the number of possible sites for offshore wind energy plants. By using a floating support platform secured by mooring lines, a wind turbine can be installed in waters exceeding the 30m depth that limits installation of conventional bottom-fixed offshore wind turbines. However, to be economically viable advances in floating offshore wind turbine system design and deployment are necessary to significantly reduce the cost and improve the reliability of floating wind turbines. This thesis develops a model-based simulation of floating offshore wind turbines in the MATLAB/Simulink environment. When necessary, the National Renewable Energy Laboratory's FAST code is used to conduct wind turbine simulations. Methods to link FAST to Simulink are developed in this thesis to accomplish this task. Modeling the wind turbine in the Simulink environment enables an efficient system level view of the entire wind turbine system. A number of design approaches to reduce the cost of offshore turbines are proposed in this thesis and studied in this modeling environment. A doubly-fed induction generator (DFIG) is proposed for wind turbine application. The primary advantage of DFIGs for wind turbines is that they allow the amplitude and frequency of their output voltages to be maintained at a constant value, no matter the wind speed. Because of this feature, DFIGs can be directly connected to the AC power network and remain synchronized at all times with that power network. Another advantage is the ability to control the power factor while keeping the power electronic devices in the wind turbine at a moderate size. In order to link a Simulink DFIG model to FAST, the model must be expressed in time domain. This thesis develops the time-domain modeling and simulation of DFIGs. Floating offshore wind turbines encounter greatly increased loading, which decreases fatigue life. One method to reduce the cost and mitigate offshore wind turbine structural loads is the application of structural control techniques commonly used in skyscrapers and bridges. Tuned mass dampers have been used to reduce loads in simulations of offshore wind turbines. This thesis discusses expanding the structural control methods by developing a set of optimum passive and active tuned mass dampers for offshore wind turbine platforms. Additionally, a new, high-efficiency, DC/DC bidirectional converter for a power quality conditioner for floating offshore wind turbines is proposed and analyzed. The power quality conditioner is used to smooth the variable turbine power and the DC/DC bidirectional converter acts as an interface circuit between the DC bus and ultracapacitors to manage the power flow during charging and discharging modes. Simulation results and experimental results are presented to verify the operation of the converter.