Optimal Electric Power Take-Off Strategy for Surface Riding Wave Energy Converters

Abstract

Wave energy has been proven to be a significant source of renewable energy. The surface riding wave energy converter (SR-WEC) is a novel approach to capturing wave energy in small and intermediate scales. This approach uses a tube-like structure housing a permanent magnet tubular linear generator to convert the kinetic energy of the sliding magnet assembly into electrical energy. The motion of the magnet assembly is dictated by the excitation forces from the ocean waves.

The power capture from the linear generator is controlled by the power take-off (PTO) strategy. This study investigates the use of traditional PTO strategies such as passive, reactive PTO for the SR-WEC. Novel binary and binary-reactive PTOs are proposed. These novel strategies are best suited for use in the SR-WEC. A parametric optimization process for each PTO strategy is discussed.

The study also explores the design and optimization of a permanent magnet linear generator for use in the SR-WEC with low cost being the driving factor in order to keep the minimum levelized cost of energy. The design and fabrication of a small scale prototype is discussed. The challenges associated with the linear generator fabrication and use is a point of interest in this study.