Wave energy converter with enhanced amplitude response at frequencies coinciding with Swedish west coast sea states by use of a supplementary submerged body

The full-scale direct-driven wave energy converter developed at Uppsala University has been in offshore operation at the Swedish west coast since 2006. Earlier simulations have now been validated by full-scale experiment with good agreement. Based on that, a theoretical model for a passive system having optimum amplitude response at frequencies coinciding with Swedish west coast conditions has been developed. The amplitude response is increased by adding supplementary inertia by use of the additional mass from a submerged body. A sphere with neutral buoyancy is chosen as the submerged body and modeled as being below the motion of the waves. The model is based on potential linear wave theory and the power capture ratio is studied for real ocean wave data collected at the research test site. It is found that the power capture ratio for the two body system can be increased from 30% to 60% compared to a single body system. Increased velocity in the system also decreases the value for optimal load damping from the generator, opening up the possibility to design smaller units.10907471 Wave Energy Converter enhanced amplitude response Swedish west coast sea states supplementary submerged body Uppsala University offshore operation passive system optimum amplitude response neutral buoyancy waves motion potential linear wave theory power capture ratio ocean wave data collection research test site Two Body System single body system