Optimization of Wave Energy Converter Arrays by an Improved Differential Evolution Algorithm

Abstract

Since different incident waves will cause the same array to perform differently with respect to the wave energy converter (WEC), the parameters of the incident wave, including the incident angle and the incident wave number, are taken into account for optimizing the wave energy converter array. Then, the differential evolution (DE) algorithm, which has the advantages of simple operation procedures and a strong global search ability, is used to optimize the wave energy converter array. However, the traditional differential evolution algorithm cannot satisfy the convergence precision and speed simultaneously. In order to make the optimization results more accurate, the concept of an adaptive mutation operator is presented to improve the performance of differential evolution algorithm. It gives the improved algorithm a faster convergence and a higher precision ability. The three-float, five-float, and eight-float arrays were optimized, respectively. It can be concluded that the larger the size of the array is, the greater the interaction between the floats is. Hence, a higher efficiency of wave energy extraction for wave energy converter arrays is achieved by the layout optimization of the array of wave energy converters. The results also show that the optimal layout of the array system is inhomogeneously distributed and that the improved DE algorithm used on array optimization is superior to the traditional DE algorithm.

Advances and Challenges in Wave Energy Park Optimization—A Review

“…(D) GA optimization for the case of a 3-m minimum separation distance (Sharp and DuPont, 2018). (E) Optimal eight-WEC array layout obtained in Fang et al (2018) with an evolutionary algorithm and regular waves. (F) Multi-objective optimization of array with nine WECs (Arbonès et al, 2018).…”

“…modes (De Chowdhury and Manasseh, 2017;Wolgamot et al, 2017), interaction distance cut-off (Göteman et al, 2015a), a nearest neighbor approach (Sarkar et al, 2016), and Haskind's relation (Flavià and Clément, 2017) have been introduced. Both the iterative and non-iterative versions of the multiple scattering theory have been further developed and used to model the hydrodynamics of wave energy parks (Ji et al, 2015;Konispoliatis and Mavrakos, 2016;Göteman, 2017;Ruiz et al, 2017;Fang et al, 2018;Giassi and Göteman, 2018;Zheng et al, 2018Zheng et al, , 2019Liu et al, 2019). Several other analytical methods have been developed and used for wave energy park applications, including matched asymptotic expansions (McIver and Evans, 1988), multipole expansions (Linton and Evans, 1993), and Bragg scattering (Li and Mei, 2007).…”

“…Optimal configurations through single-or multi-objective optimization routines such as evolutionary algorithms were studied by Child and Venugopal (2010), Sharp and DuPont (2018), Giassi and Göteman (2018), Child et al (2011, Fang et al (2018), Arbonès et al (2018), and Neshat et al (2019b). All studies, although based on different devices, assumptions, parameters, models, and optimization algorithms, show similar layouts trends, with WECs aligned perpendicular to the incident wave field; see Figures 11-13.…”

“…optimization to active device control. An adaptive mutation factor was introduced by Fang et al (2018) to improve the convergence rate of the array optimization. Faraggiana et al (2019) used a GA to optimize the separation distance between devices, the PTO tuning, and the rated power of a system of three WaveSub WECs.…”

A New Bi-Level Optimisation Framework for Optimising a Multi-Mode Wave Energy Converter Design: A Case Study for the Marettimo Island, Mediterranean Sea

“…This is because the costs involved in producing energy using ocean waves are currently much higher than those for other renewables [6]. Therefore, in the last decade, a large number of investigations have been carried out to optimise wave energy converter (WEC) design and dimensions [7][8][9][10][11][12], power generation settings (PTO) [13,14], and the position of WECs in a wave farm [15][16][17][18][19].…”