Electromagnetic rolling mass wave energy harvester for oceanic drifter applications

Abstract

Ocean monitoring requirements have fomented the evolution of sensor platforms such as Lagrangian drifters, whose autonomy is a critical factor in the design process. Energy Harvesting (EH) has proven to be a sound option as an autonomous power source for sensor platforms. This paper deals with the design and simulation of a kinetic energy harvester (KEH) that captures energy from a drifter’s motion under wave excitation. This KEH is based on a rolling mass resonator with permanent magnets that oscillate with respect to a frame which includes a coil system. The induced current on the coil results from the relative motion of the rolling mass, whose natural frequency is tuned to match the drifter’s to achieve resonance. Preliminary simulations using OrcaFlex provide the motion vectors of the drifter, used to excite the KEH’s frame. A multi-body MSC.ADAMS model has been developed consisting of a simple DOF mass-spring-damper system that includes the frame motion and the electrical and electromagnetic models. Results provide an estimation of the power generated on a resistive load, showing 23 mJ harvested during a one-minute simulation.