Optimisation- vs. non-optimisation- based energy-maximising control for wave energy converters: A case study

FAEDO, NICOLAS; DEMIÁN GARCÍA VIOLINI; PENA-SANCHEZ, YERAI; JOHN RINGWOOD

Saint Petersburg

Congreso; European Control Conference (ECC 20); 2020

Energy-maximising control of wave energy converters can be separated into two different worlds: optimisation and non-optimisation based strategies. While optimisationbased controllers can outperform non-optimisation based strategies, the computational requirements associated with numerical optimisation routines, and the high control forces required under optimality conditions, can render these energymaximising control laws not suitable for realistic scenarios.Non-optimisation-based controllers present an alternative path, where linear time-invariant systems are used to approximate the so-called impedance-matching condition. These strategies are often extremely simple to implement but suffer from considerable performance degradation when considering motion constraints. This paper aims to present a critical comparison between both families of controllers, highlighting the strengths and weaknesses of each energy-maximising approach. We present simulation results for a state-of-the-art CorPower-likedevice under polychromatic (irregular) wave excitation, for both (motion) unconstrained and constrained scenarios.