Experimental and CFD Assessment of Harmonic Characteristics of Point-Absorber Wave-Energy Converters with Nonlinear Power Take-Off System

Nonlinear control of flap-type wave energy converter with a non-ideal power take-off system

Wave energy converters (WECs) require active control to maximise energy capture over a wide range of sea conditions, which is generally achieved by making the device resonate. The exaggerated device motion arising at resonance, however, may result in nonlinear effects that are ignored by the linear models that are typically employed. In particular, nonlinear viscous forces are significant for p...

Performance of arrays of direct-driven wave energy converters under optimal power take-off damping

Vibration Analysis of a Nonlinear System with a Nonlinear Absorber under the Primary and Super-harmonic Resonances (TECHNICAL NOTE)

Abstract   In vibratory systems, linear and nonlinear vibration absorbers can be used to suppress the primary and super-harmonic resonance responses. In this paper, the behavior of a nonlinear system with a nonlinear absorber, under the primary and super-harmonic resonances is investigated. The stiffnesses of the main system and the absorber are cubically nonlinear and the dampers are linear. M...

Different Model Predictive Control Approaches for Controlling Point Absorber Wave Energy Converters

Ocean wave energy is a promising renewable energy source that can be converted into useful electrical energy using wave energy converters (WECs). In order for WECs to become a commercially viable alternative to established methods of energy generation, operating the WEC in an optimal fashion is a key task. Thus, model predictive control (MPC) is an encouraging control method that exploits the e...

Discrete Displacement Hydraulic Power Take-Off System for the Wavestar Wave Energy Converter

The Wavestar Wave Energy Converter (WEC) is a multiple absorber concept, consisting of 20 hemisphere shaped floats attached to a single platform. The heart of the Wavestar WEC is the Power Take-Off (PTO) system, converting the wave induced motion of the floats into a steady power output to the grid. In the present work, a PTO based on a novel discrete displacement fluid power technology is expl...