Maximizing the Efficiency of Wave-Energy Plant Using Complex-Conjugate Control

A method of determining the hydrodynamic coefficients of a floating wave-energy absorber is outlined, and the coefficients of a Salter's duck are measured experimentally. A complex-conjugate synthesizer, derived from these coefficients, is used both theoretically and experimentally to predict and to measure the efficiency of a duck in unidirectional monochromatic waves. The synthesis produces a higher efficiency over a greater bandwidth than has been achieved before. The reason for the improvement in efficiency is explained, and conclusions are drawn about the implications of complex-conjugate control for predicting practical engineering constraints on the design of a full-sized wave-energy absorber.