Development of a Wave Energy Converter with Mechanical Power Take-Off via Supplementary Inertia Control

Abstract

To reduce environmental pollution, alternative renewable energy resources have been explored for decades. Wave energy has a high energy density, high utilization time and no fuel costs, so it is considered as the most promising alternative to the fossil fuel resources. The number of studies of wave energy converters (WECs) has rapidly increased. This paper proposes a new method to achieve the resonant behavior of a point absorber floating buoy type of WEC using a mechanical power take-off system. By using the inertia characteristics of a hydraulic flywheel accumulator-based electro-hydraulic actuator to change the corresponding supplementary mass of the floating buoy, the total mass of the buoy was close to a match with the relatively low frequency of the wave, so that the buoy was in resonance with the wave. The specifications of the hydraulic flywheel accumulator system were proposed and studied. The working principle was analyzed, and a mathematical model was then derived to investigate the system operation. An experimental set-up was implemented to validate the mathematical model. Numerical simulation using MATLAB/Simulink was done to evaluate the operation of the system.