Control-Informed Optimal Array Layout for Wave Farms

Somewhat similar to wind farms, commercial wave energy will be realized using farms of devices. However, for wave farms, both constructive and destructive interference may occur between individual devices; whereas, for wind farms, only destructive interference occurs. In order to maximize constructive interference, the layout of the wave farm must be optimized. In addition, power absorption may be improved by applying a control system technology to the farm of devices. As with many applications, there is a tendency in wave energy to separate the design of the array layout from the design of an energy maximizing control system. In this paper, we show that integrating the activities of optimal array layout design and control design are crucial if the full potential of the wave farm is to be realized. In particular, we show that a layout optimized without knowledge of the control system to be used can be inferior to the extent of recovering 40% less energy than a farm layout optimized with knowledge of the control system. This loss is significantly more than the difference in performance between a simple and a very complex control strategy.

[1]  Matthew Folley,et al.  The effect of sub-optimal control and the spectral wave climate on the performance of wave energy converter arrays , 2009 .

[2]  John Ringwood,et al.  Control-Influenced Layout Optimization of Arrays of Wave Energy Converters , 2014 .

[3]  J. Ringwood,et al.  A control system for a self-reacting point absorber wave energy converter subject to constraints , 2011 .

[4]  D. Evans,et al.  Arrays of three-dimensional wave-energy absorbers , 1981 .

[5]  Leo R. M. Maas,et al.  Experimental verification of Lorentz’ linearization procedure for quadratic friction , 2005 .

[6]  M. Leijon,et al.  Performance of large arrays of point absorbing direct-driven wave energy converters , 2013 .

[7]  António F.O. Falcão,et al.  Modelling and control of oscillating-body wave energy converters with hydraulic power take-off and gas accumulator , 2007 .

[8]  P. Mciver,et al.  Comparison of methods for computing hydrodynamic characteristics of arrays of wave power devices , 1997 .

[9]  J. Falnes.  Ocean Waves and Oscillating Systems: Linear Interactions Including Wave-Energy Extraction , 2002 .

[10]  Michael Conlon,et al.  Maximising Value of Electrical Networks for Wave Energy Converter Arrays , 2013 .

[11]  A. Babarit.  Impact of long separating distances on the energy production of two interacting wave energy converters , 2010 .

[12]  Guang Li,et al.  Model predictive control of sea wave energy converters – Part II: The case of an array of devices , 2014 .

[13]  W. Cummins.  THE IMPULSE RESPONSE FUNCTION AND SHIP MOTIONS , 2010 .

[14]  J. Cruz,et al.  Estimating the loads and energy yield of arrays of wave energy converters under realistic seas , 2010 .

[15]  T. Moan,et al.  Mooring system analysis of multiple wave energy converters in a farm configuration , 2009 .

[16]  John V. Ringwood,et al.  Coordinated Control of Arrays of Wave Energy Devices—Benefits Over Independent Control , 2013, IEEE Transactions on Sustainable Energy.

[17]  W. E. Cummins,et al.  The Impulse Response Function and Ship Motion , 1962 .

[18]  R. E. Taylor,et al.  The interaction factor and directionality in wave energy arrays , 2012 .

[19]  D. V. Evans,et al.  Approximation of wave forces on cylinder arrays , 1984 .

[20]  Inigo J. Losada,et al.  Factors that influence array layout on wave energy farms , 2014 .

[21]  K. Budal.  Theory for Absorption of Wave Power by a System of Interacting Bodies , 1977 .

[22]  J. Falnes.  Radiation impedance matrix and optimum power absorption for interacting oscillators in surface waves , 1980 .

[23]  F. Fusco,et al.  A Simple and Effective Real-Time Controller for Wave Energy Converters , 2013, IEEE Transactions on Sustainable Energy.

[24]  V. Venugopal,et al.  Optimal configurations of wave energy device arrays , 2010 .