A novel fully floating three-body system for direct-drive wave energy converter

Abstract

Converting persistent and renewable wave energy into electricity has been studied in recent years. This research develops a novel fully floating three-body direct-drive wave energy converter (DD-WEC) prepared for the research of the multi-body DD-WEC. Its prototype consists of three floating bodies, but both three bodies act as buoys to extract the wave energy, not just a body. And the relative motion of the buoys induces the voltage in Halbach array permanent magnet linear generators coils. Its feasibility is investigated theoretically by analyzing the dynamics of motion of the floating buoys. As a result, parametric design of the WEC is achieved. The load performance of the DD-WEC is investigated by using the Simulink, and it can be found that the relative displacements between buoys are different. Then, the electromagnetic power of the proposed WEC is much higher compared to a two-body DD-WEC by using numerical simulation Finally, the DD-WEC prototype is manufactured and tested in the wave tank. The results show that the WEC can produce the most electricity for the case with the wave period of 1.6 s, and the maximum voltage reaches 14.2 V, which is consistent with the simulation results. The results show that the proposed DD-WEC is well suited for wave energy conversion.