Wind Turbine Gust Prediction

Offshore wind power generation is a key component of the UK's commitment to deliver 15% of gross final energy consumption from renewable sources by 2020. Efforts to meet this target are prompting the design of ever larger turbines in order to capture more energy from the wind. However, as these structures grow taller, they become increasingly vulnerable to violent gusts of wind and other turbulent flow phenomena that are the primary cause of severe turbine damage. Advance warning of such gusts will enable turbine control systems to take preventative action, and so the ability to predict the strength of an oncoming gust is widely regarded within the wind energy industry as being a problem of critical importance.

This research project will seek to overcome this problem by demonstrating a system that can accurately forecast the velocity profile of an oncoming wind, given only limited spatial measurements from state-of-the-art light detection and ranging (LIDAR) units. This approach will exploit recent interdisciplinary advances in the application of optimal estimation techniques, from the control systems community, to fluid-mechanical systems governed by the Navier-Stokes equations. The research will draw upon the PI's existing expertise in dynamical estimation of fluid flows and the project results will feed into the host institute's current industrial collaboration with Vestas Wind Systems, who have agreed to provide the data and technical support required to maximise research impact.

The practical application of this work will be a gust detection system for use by the wind-energy industry. The key innovation will be the system's ability to predict the velocity profile of the oncoming wind in a sufficiently timely manner to enable a turbine control system to act in advance to maximise energy capture and minimise structural loading. This will pave the way for the industry to construct lighter, and therefore less expensive turbines, whilst reducing the unbalanced loadings upon turbine generators that are a principal cause of component failures. This will ultimately reduce the end cost to the consumer of the renewable energy generated from this technology, and thus improve its economic competitiveness against power generation from fossil-fuel based approaches. To this end, the host department recently entered a partnership in control systems research and development with Vestas Wind Systems. The results of the proposed research project will therefore be fast-tracked to the key individuals within the wind energy industry with the authority and knowledge to convert proof-of-concept into viable technology.

This research has been discussed with senior members of Vestas' Technology Centre, and they have subsequently agreed to host visits from the PI and post-doctoral research associate at Vestas' London office. These meetings will be used to discuss the technical aspects of the work and to present the research outputs with a view to commercial exploitation and further industrial funding, either directly or via a knowledge transfer account. It is anticipated that these meetings will identify commercially exploitable technology arising from the project, in which case the University of Sheffield's research and innovation team will be engaged to discuss the transfer of intellectual property.

The outcome of the project will naturally lead to further research in designing turbine controllers to use such predictions in an optimal fashion. To this end, the PI plans to apply for CASE studentships in conjunction with Vestas to support such work. This will provide training for high-quality PhD students in the field of flow-control and estimation, further expanding the UK's expertise, both industrially and academically, in this emerging and important interdisciplinary field.

To ensure the proposed research achieves significant impact, the dissemination of the research findings will be tailored towards relevant beneficiaries. The PI will manage the dissemination of results, with input from Vestas and the host department where necessary. In terms of technical content, the dissemination of research will be structured as follows:

1. The theoretical contributions will be disseminated to relevant communities, specifically the control systems and fluid mechanics communities. This will be achieved through journal publications, conferences and seminars.

2. The main technical results will be disseminated to the wind-energy industry, with an emphasis upon practical application. Dissemination will be via appropriate technology fairs and conferences.

3. The research outputs disseminated to the wider public will place emphasis on the relevance and importance of the work, and will do so at an appropriate technical level. This will be achieved through outreach programs, demonstrations and a purpose-built website. This will be linked to the host department's homepage and will explain the research outlined in this proposal. Links to the publications resulting from this work will be added, as will visual simulations of the flow to convey the central ideas behind the flow prediction scheme. In this way, the general public, as well as more technically minded readers will find access to the research. The PI will also work closely with the host department's undergraduate admission's officer to present the research at undergraduate open days to inspire prospective students to pursue a career in engineering.