Enhancing buoy-based swinging energy harvesters through bat algorithm optimization: a comprehensive study

Abstract

Abstract Due to the threat of greenhouse gas emissions on Earth's sustainability, low carbon with green energy is crucial. Ocean hydropower is inexhaustible, with wave energy being a feasible green energy source. Previous low-frequency domain wave energy capture mainly used linear piston-type electromagnetic induction generators. However, this method produced weak electrical energy. To address this, a novel wave power generation method is proposed. It involves setting up a raft-like float, which is pushed by waves. A spring and damping assembly for buffering is added between the float and a vertical rod. The spring and damping assembly connect to a rod element online, and through a rod and gear mechanism, convert the float's linear motion into oscillatory motion to drive a generator. A raft-style float for sufficient buoyancy and a rod and gear mechanism to convert linear motion into rotational motion, driving a generator is adopted to produce more significant electrical energy. This study adopts a Lagrangian energy method and complex variable functions to deal with a double-mass dynamic system. Additionally, using a surface sinusoidal wave with amplitude of 0.3 m and a frequency of 2 rad/s as an example, the study combines bat algorithms to optimize the energy harvester for maximum power generation. Consequently, simulations demonstrate a maximal electrical power output of 4470 watts. The applied force and moment on the gear to induce electrical power measure 19 000 N and 5700 N-m, respectively.