Pelamis Wave Energy Converter - Verification of full-scale control using a 7th scale model: Final Report

Abstract:

<p>The Pelamis Wave Energy Converter (WEC) is an innovative concept for extracting energy from ocean waves and converting it into a useful product such as electricity, direct hydraulic pressure or potable water. The system is a semi-submerged, articulated structure composed of cylindrical sections linked by hinged joints. The wave-induced motion of these joints is resisted by hydraulic rams that pump high-pressure oil through hydraulic motors via smoothing accumulators. The hydraulic motors drive electrical generators to product electricity. The complete machine is flexibly moored so as to swing head-on to the incoming waves and derives its 'reference' from spanning successive wave crests.</p> <p>The Pelamis WEC development programme OPD identified a requirement for an intermediate scale 'systems' demonstrator with which to develop and prove the full-scale Pelamis hydraulic, control and data acquisition systems. A 7^th scale model was conceived to satisfy the OPD ethos of systematically tackling each aspect of technical risk before committing to a full-scale prototype. It is seen as absolutely critical to the overall success of the technical programme that as little immature technology as possible is incorporated within the first full-scale prototype.</p> <p>In addition, during the programme of work undertaken here it was felt that further control studies using and updated version of the 20^th scale model also had considerable merit.</p> <p>The overall objectives of the project were: <bl> <li>Maximise the return on the 7^th scale investment to the project in terms of minimising the onward risks.</li> <li>Verify control system hardware, algorithms and software for use in the full-scale prototype.</li> </bl></p> This report contains an executive summary, and is divided into the two sections, being 'Section A - 7^th Scale Tests' and 'Section B - 20^th Scale Tests': <ul> <li>A1. Summary</li> <li>A2. 7^th Scale Model General Configuration</li> <li>A3. Model Upgrades</li> <li>A4. Transport & Installation</li> <li>A5. Testing & Analysis</li> <li>A6. Conclusions</li> <li>B1. Introduction</li> <li>B2. Testing & Analysis</li> <li>B3. Model Decommissioning & Maintenance</li> <li>B4. Conclusions</li> <li>Project Conclusions</li> <li>Recommendations for Future Work</li> </ul>

Author(s):

DTI