Order of magnitude power increase from multi-resonance wave energy converters

A Complex Conjugate (CC) control is implemented with a Proportional-Derivative (PD) controller for WEC devices to improve and optimize power absorbed. Traditionally, CC control has not been realizable due to actual implementation that requires acceleration feedback or exact term cancellation. For the PD implementation, only the stiffness term is employed to modify the impedance and achieve resonance matching conditions without the drawbacks of traditional CC realization. A simple least squares estimator model is employed to approximate the amplitudes of a harmonic series to support the feedack signal to the PD controller which does not require wave prediction information.