Optimising Reactive Control in Non-Ideal Efficiency Wave Energy Converters

2014 ◽  
Author(s):  
T. Strager ◽  
A. Martin dit Neuville ◽  
P. Fernández López ◽  
G. Giorgio ◽  
T. Mureşan ◽  
...  
Keyword(s):  
Optimal Control ◽  
Wave Energy ◽  
Electrical Power ◽  
Control Parameters ◽  
Reactive Control ◽  
Simple Method ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
The Mean ◽  
Energy Converters

When analytically optimising the control strategy in wave energy converters which use a point absorber, the efficiency aspect is generally neglected. The results presented in this paper provide an analytical expression for the mean harvested electrical power in non-ideal efficiency situations. These have been derived under the assumptions of monochromatic incoming waves and linear system behaviour. This allows to establish the power factor of a system with non-ideal efficiency. The locus of the optimal reactive control parameters is then studied and an alternative method of representation is developed to model the optimal control parameters. Ultimately we present a simple method of choosing optimal control parameters for any combination of efficiency and wave frequency.

Ocean Wave Energy Converters and Control Methodologies

2013 ◽  
Author(s):  
Jingjin Xie ◽  
Lei Zuo
Keyword(s):  
Wave Energy ◽  
Ocean Wave ◽  
Reactive Control ◽  
Floating Bodies ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Ocean Wave Energy ◽  
Latching Control ◽  
And Control ◽  
Energy Converters

Ocean wave energy is an indirect form of solar energy with great potential worldwide. Technologies on extracting energy from the ocean wave have been explored for centuries and are still undergoing with challenges. The nature of ocean wave and ocean wave energy are introduced with their mathematical models in this paper. The features and working principles of three forms of mainstream ocean wave energy converters (OWEC), including floating bodies (point absorber, attenuator, and terminator), oscillating water column (OWC) and wave overtopping, are presented together with their hydrodynamic performances. The corresponding control methodologies for these ocean wave energy converters, such as latching control, declutch control, reactive control, model predictive control (MPC), etc., are analyzed in a comprehensive manner thereafter. Optimal conditions for maximum power absorption are also introduced with mathematical modeling and derivations.

scholarly journals Hardware-in-the-Loop Validation of Model Predictive Control of a Discrete Fluid Power Power Take-Off System for Wave Energy Converters

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3668
Author(s):  
Anders H. Hansen ◽  
Magnus F. Asmussen ◽  
Michael M. Bech
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Wave Energy ◽  
Fluid Power ◽  
Wave Power ◽  
Reactive Control ◽  
Power Extraction ◽  
Wave Energy Converters ◽  
Extraction Algorithm ◽  
Energy Converters

Model predictive control based wave power extraction algorithms have been developed and found promising for wave energy converters. Although mostly proven by simulation studies, model predictive control based algorithms have shown to outperform classical wave power extraction algorithms such as linear damping and reactive control. Prediction models and objective functions have, however, often been simplified a lot by for example, excluding power take-off system losses. Furthermore, discrete fluid power forces systems has never been validated experimentally in published research. In this paper a model predictive control based wave power extraction algorithm is designed for a discrete fluid power power take-off system. The loss models included in the objective function are based on physical models of the losses associated with discrete force shifts and throttling. The developed wave power extraction algorithm directly includes the quantized force output and the losses models of the discrete fluid power system. The experimental validation of the wave power extraction algorithm developed in the paper shown an increase of 14.6% in yearly harvested energy when compared to a reactive control algorithm.

Experimental and numerical comparisons of self-reacting point absorber wave energy converters in regular waves

2015 ◽  
Vol 104 ◽  
pp. 370-386 ◽  
Author(s):  
Scott J. Beatty ◽  
Matthew Hall ◽  
Bradley J. Buckham ◽  
Peter Wild ◽  
Bryce Bocking
Keyword(s):  
Wave Energy ◽  
Regular Waves ◽  
Numerical Comparisons ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Energy Converters

Performance assessments of the fully submerged sphere and cylinder point absorber wave energy converters

2019 ◽  
Vol 33 (13) ◽  
pp. 1950168 ◽  
Author(s):  
Qianlong Xu ◽  
Ye Li ◽  
Yingkai Xia ◽  
Weixing Chen ◽  
Feng Gao
Keyword(s):  
Wave Height ◽  
Wave Energy ◽  
Interaction Analysis ◽  
Wave Power ◽  
Viscous Damping ◽  
Power Performance ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Submerged Sphere ◽  
Energy Converters

Fully submerged sphere and cylinder point absorber (PA), wave energy converters (WECs) are analyzed numerically based on linearized potential flow theory. A boundary element method (BEM) (a radiation–diffraction panel program for wave-body interactions) is used for the basic wave-structure interaction analysis. In the present numerical model, the viscous damping is modeled by an equivalent linearized damping which extracts the same amount of wave energy over one cycle as the conventional quadratic damping term. The wave power capture width in each case is predicted. Comparisons are also made between the sphere and cylinder PAs which have identical geometrical scales and submerged depths. The results show that: (i) viscous damping has a greater influence on wave power performance of the cylinder PA than that of the sphere PA; (ii) the increasing wave height reduces wave power performance of PAs; (iii) the cylinder PA has a better wave power performance compared to the sphere PA in larger wave height scenarios, which indicates that fully submerged cylinder PA is a preferable prototype of WEC.

scholarly journals Adaptive Optimal Control of Wave Energy Converters

2018 ◽  
Vol 51 (29) ◽  
pp. 38-43 ◽  
Author(s):  
Siyuan Zhan ◽  
Bin Wang ◽  
Jing Na ◽  
Guang Li
Keyword(s):  
Optimal Control ◽  
Wave Energy ◽  
Adaptive Optimal Control ◽  
Wave Energy Converters ◽  
Energy Converters
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