Offshore Wind Power Technology Development and Testing of a Downscaled Pitch Controlled Wind Turbine

Masteroppgave i mekatronikk - Universitetet i Agder, 2015The energy demand of the world increases day by day, and at the same time people become more aware of the impact fossil energy sources have on the climate. This leads to an increased focus on renewable energy sources, such as wind power, which has been pointed out as an important contributor to the production of renewable energy. In recent years the focus has shifted from land based wind farms towards the possibilities of the large energy potential that exist in the open ocean along the coast line. The background of the thesis is motivated by the increased focus on offshore wind power technology. State of the art technology in the field of floating offshore wind power was reviewed in the first part in addition to relevant background theory regarding design and operation of wind turbines. The main objective has been to develop and test a downscaled pitch controlled wind turbine. A pitch mechanism was designed to turn the blade pitch angle to a given angle with a stepper motor. The stepper motor transfers rotational movement with a leading screw to translational movement of a sliding mechanism. The sliding mechanism rotates the angle of the blade shaft to the optimal calculated angle. Control of the stepper motor is achieved by a PLC step drive and a ladder diagram describing the desired functionality. Optimized pitch angles are calculated and implemented as a function with the current wind speed as input. The wind speed is measured with an anemometer and connected to the PLC as an analogue signal. From the PLC the signals are logged with an OPC server and processed in Excel. The wind turbine was tested on the campus roof top. The cut-in speed was as expected, and the turbine require between 3 and 5 m/s to start to rotate depending on the angle of the wind, while cut-out speed is around 17 m/s, due to high risk of malfunction and destruction of parts or components. The voltage was measured to be around 150-250 mV at optimal wind speed 9 m/s and the maximum obtained shaft speed generated about 280 mV. More extensive testing should be performed in order to obtain more reliable results and complete verify the model. Some improvements has been discussed, including implementing a gearbox, redesigning the blades with a different profile as well as material. A proper test site with more easily controllable wind speeds is preferable

MOD-1 Wind Turbine Generator Analysis and Design Report, Volume 2

The MOD-1 detail design is appended. The supporting analyses presented include a parametric system trade study, a verification of the computer codes used for rotor loads analysis, a metal blade study, and a definition of the design loads at each principal wind turbine generator interface for critical loading conditions. Shipping and assembly requirements, composite blade development, and electrical stability are also discussed

Assessment of a Space Shuttle trajectory evaluation system (DOLILU II)

DOLILU II is a ground control system that generates space shuttle\u27s launch trajectories, first stage guidance commands and verifies whether the generated trajectories are safe for the flight. It is a safety critical system and a high degree of confidence in its safety and reliability must be gained through assessment. We addressed three issues related to its safety and reliability assessment. We developed a reliability assessment framework for DOLILU II system. We proposed techniques to speed up test case execution and designed methodologies for the generation of input conditions needed to test the system.;We used a Bayesian statistical framework for reliability assessment. Bayesian statistics uses knowledge about the system to be incorporated into the reliability model before testing. DOLILU II has been operational for nearly five years. We use this information when developing the reliability model. This information is introduced in the form of prior beliefs.;DOLILU II system requires an average time of 30 minutes for each test run. This translates into a large time period required for testing to demonstrate that DOLILU II exhibits the required failure rate. Vertical slicing, a semantic transformation technique, is used to prove the possibility of parallel execution and enhance each test case execution.;DOLILU II is an on-demand system. Many test trajectories are needed for its assessment. Regression methods were used to develop models for the generation of input data

Application of Reynolds Stress Model Using Direct Modeling and Actuator Disk Approaches for a Small-Scale Wind Turbine

The Reynolds Stress Model (RSM) has been avoided for turbulence closure in CFD simulations of wind turbines, largely due to the computational expense and the high potential for numerical instability. The advantage of using RSM is having access to shear stresses that are not available from two-equation RANS-based closure models like k-e and k-w. Access to the shear stresses will aide in the understanding of how the blade design will affect the wake, particularly in the near-wake region. In this research, the RSM turbulence model has been successfully applied in simulating a three-bladed small-scale wind turbine through a direct-model approach and an actuator disk approach. In the direct-model method, the turbine blades were discretized within a rotating subdomain and in the actuator disk method, the turbine blades were modeled as a rotating disk using the Virtual Disk model available in Star CCM+. The transient Rigid Body Motion (RBM) simulation was able to accurately predict velocity deficit and tip vortices that compared well with hot-wire measurements and high speed images. The actuator disk method is more practical in simulating wind farms due to the simplified mesh and requires accurate information for lift and drag coefficients. Experimental results showed interaction between the tower and rotating blades can create significant turbulence in the wake. Experiments with multiple turbines showed how each turbine contributed to the velocity deficit and total turbulence intensity. For the experimental blade design, the velocity deficit recovered and turbulence intensity had dissipated within three rotor diameters

Mathematical model for lift/cruise fan V/STOL aircraft simulator programming data

Simulation data are reported for the purpose of programming the flight simulator for advanced aircraft for tests of the lift/cruise fan V/STOL Research Technology Aircraft. These simulation tests are to provide insight into problem areas which are encountered in operational use of the aircraft. A mathematical model is defined in sufficient detail to represent all the necessary pertinent aircraft and system characteristics. The model includes the capability to simulate two basic versions of an aircraft propulsion system: (1) the gas coupled configuration which uses insulated air ducts to transmit power between gas generators and fans in the form of high energy engine exhaust and (2) the mechanically coupled power system which uses shafts, clutches, and gearboxes for power transmittal. Both configurations are modeled such that the simulation can include vertical as well as rolling takeoff and landing, hover, powered lift flight, aerodynamic flight, and the transition between powered lift and aerodynamic flight

A World-Class University-Industry Consortium for Wind Energy Research, Education, and Workforce Development: Final Technical Report

During the two-year project period, the consortium members have developed control algorithms for enhancing the reliability of wind turbine components. The consortium members have developed advanced operation and planning tools for accommodating the high penetration of variable wind energy. The consortium members have developed extensive education and research programs for educating the stakeholders on critical issues related to the wind energy research and development. In summary, The Consortium procured one utility-grade wind unit and two small wind units. Specifically, the Consortium procured a 1.5MW GE wind unit by working with the world leading wind energy developer, Invenergy, which is headquartered in Chicago, in September 2010. The Consortium also installed advanced instrumentation on the turbine and performed relevant turbine reliability studies. The site for the wind unit is InvenergyÃÂÃÂÃÂâÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂs Grand Ridge wind farmin Illinois. The Consortium, by working with Viryd Technologies, installed an 8kW Viryd wind unit (the Lab Unit) at an engineering lab at IIT in September 2010 and an 8kW Viryd wind unit (the Field Unit) at the Stuart Field on IITÃÂÃÂÃÂâÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂs main campus in July 2011, and performed relevant turbine reliability studies. The operation of the Field Unit is also monitored by the Phasor Measurement Unit (PMU) in the nearby Stuart Building. The Consortium commemorated the installations at the July 20, 2011 ribbon-cutting ceremony. The ConsortiumÃÂÃÂÃÂâÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂs researches on turbine reliability included (1) Predictive Analytics to Improve Wind Turbine Reliability; (2) Improve Wind Turbine Power Output and Reduce Dynamic Stress Loading Through Advanced Wind Sensing Technology; (3) Use High Magnetic Density Turbine Generator as Non-rare Earth Power Dense Alternative; (4) Survivable Operation of Three Phase AC Drives in Wind Generator Systems; (5) Localization of Wind Turbine Noise Sources Using a Compact Microphone Array; (6) Wind Turbine Acoustics - Numerical Studies; and (7) Performance of Wind Turbines in Rainy Conditions. The ConsortiumÃÂÃÂÃÂâÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂs researches on wind integration included (1) Analysis of 2030 Large-Scale Wind Energy Integration in the Eastern Interconnection; (2) Large-scale Analysis of 2018 Wind Energy Integration in the Eastern U.S. Interconnection; (3) Integration of Non-dispatchable Resources in Electricity Markets; (4) Integration of Wind Unit with Microgrid. The ConsortiumÃÂÃÂÃÂâÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂs education and outreach activities on wind energy included (1) Wind Energy Training Facility Development; (2) Wind Energy Course Development; (3) Wind Energy Outreach

Mod-5A Wind Turbine Generator Program Design Report. Volume 2: Conceptual and Preliminary Design, Book 1

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. There are four volumes. In Volume 2, book 1 the requirements and criteria for the design are presented. The conceptual design studies, which defined a baseline configuration and determined the weights, costs and sizes of each subsystem, are described. The development and optimization of the wind turbine generator are presented through the description of the ten intermediate configurations between the conceptual and final designs. Analyses of the system's load and dynamics are presented