Abstract
Within wave energy a large challenge remains in designing a Power Take-Off (PTO) system capable of converting the slow oscillations induced by waves into electricity. Fluid power is an essential part of most PTO-concepts. To implement an efficient control of the load force produced by a cylinder on a floating body, throttle-less force control by discrete variation of the effective cylinder area has been investigated and found feasible for the Wavestar wave energy concept. However, the feasibility study assumes adequate valve performance, such that only the compression loss remains. This paper investigates the required valve performance to achieve this energy efficient operation, while meeting basic dynamic requirements. The components making up the total energy loss during shifting is identified by analytically expressing the losses from the governing differential equations. From the analysis a framework for evaluating the adequacy of a valve’s response is established, and the analysis shows the results may be normalised for a wider range of systems. Finally, the framework is successfully applied to the Wavestar converter.
Original language | English |
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Title of host publication | Proceedings of ASME Symposium on Fluid Power and Motion Control, FPMC 2012 |
Editors | Nigel Johnston, Andrew R. Plummer |
Place of Publication | Great Britain |
Publisher | American Society of Mechanical Engineers |
Publication date | 2012 |
Pages | 565-578 |
ISBN (Print) | 978-0-086197-187-9 |
ISBN (Electronic) | 978-0-086197-188-6 |
Publication status | Published - 2012 |
Event | ASME 2012 6th International Conference on Energy Sustainability & 10th Fuel Cell Science, Engineering and Technology Conference - San Diego, United States Duration: 23 Jul 2012 → 26 Jul 2012 |
Conference
Conference | ASME 2012 6th International Conference on Energy Sustainability & 10th Fuel Cell Science, Engineering and Technology Conference |
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Country/Territory | United States |
City | San Diego |
Period | 23/07/2012 → 26/07/2012 |