- Title
- Urban wind gusts and their effect on the performance of a small wind turbine
- Creator
- Rakib, Muhammad Iftekharul
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2022
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Small wind turbines (rotor swept area <200 m2) are installed into urban regions either incorporated as part of a building structure or mounted on a tower. Wind gust events in urban environments occur more frequently than stipulated in IEC 61400.2–2013. The prime objective of this thesis is to understand the behaviour of urban wind gusts and to measure the impact on the operation and performance of small wind turbines. Wind resource at the wind turbine site located on the Callaghan campus of The University of Newcastle, Australia was assessed using an array of three 3D ultrasonic anemometers (20 Hz) over a two-year long measurement campaign. Specific focus was placed on capturing both extreme operating gusts (EOG) and extreme coherent gusts (ECG). During the measurement campaign, 123 IEC EOG events were identified along with 417 unclassified non-IEC EOG events. This is compared to the standard that only assumes 1 (one) EOG per year. The non-IEC EOGs had rise-and-fall time greater than the IEC standard prescribed time of 6 s. In addition, a total of 240 ECG events were also identified during the measurement campaign. Results show that stronger and higher amplitude gusts occur at the Callaghan urban site than suggested by IEC gust models. Methodology of estimating the gust factor for an urban site is detailed in this thesis. The estimated gust factor for Callaghan site was found to be between 1.5 and 1.7, which is 7% to 21% higher respectively than the IEC prescribed gust factor of 1.4 used for the design of small wind turbines. A two-bladed 5 kW horizontal-axis wind turbine was instrumented to measure the effects of urban gusts on its operation, performance and straining of the blades. Results show ECG gusts are likely to result in higher blade strains than for EOG gusts for the same gust amplitude. The change of measured blade strain was found to be increase linearly with an increase in the gust amplitude. Wind turbine performance parameters including generated electrical power, rotor speed, nacelle yaw, and nacelle yaw rate were measured during the measurement campaign. The increase of power output during a non-IEC gust was found to be 65% higher than an IEC gust event. It is likely that a long rise-and-fall time (> 6s) of the non-IEC gust allowed the turbine control system to generate more electrical power than IEC gust event. Results also show that more aerodynamic energy was converted to electrical energy during non-IEC EOG than IEC EOG. The generated electrical energy during EOG events was found to be increased linearly with gust rise-and-fall time. Finally, this thesis also details aeroelastic simulations in FAST using the measured wind gust data as input to predict the response of the turbine that was not measured during the measurement campaign due to lack of instrumentation.
- Subject
- small wind turbine; urban wind resource; wind gusts; turbine performance; gust factor
- Identifier
- http://hdl.handle.net/1959.13/1475113
- Identifier
- uon:49455
- Rights
- Copyright 2022 Muhammad Iftekharul Rakib
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 21 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 540 KB | Adobe Acrobat PDF | View Details Download |