Experimental trials of a sealed ocean kinetic energy harvester for underwater mooring platforms

A full-scale prototype of sealed ocean kinetic energy harvester for underwater mooring platforms was tested on a Stewart platform, a 6-degree-of-freedom ocean motion simulation device, and the overall sealed ocean kinetic energy harvester concept was confirmed. Initial results were collected and significant insights discovered. Experimental results show that the optimal resonant frequency for maximum power output is 1 Hz at high load resistances (large amplitude), or is 1.1 Hz at low load resistances (small amplitude), due to the nonlinear effect. It also demonstrates that the optimal output power takeoff damping is 300 Ω at 1.1 Hz resonant frequency or is 600 Ω at 1.0 Hz resonant frequency or is 100 Ω at nonresonant frequencies. Moreover, the fluctuation impulses in output power curve indicate that the sealed ocean kinetic energy harvester needs great overload capability, and the energy storage system is essential to even out power fluctuations.