On the power performance of a wave energy converter with a direct mechanical drive power take-off system controlled by latching

Author(s):  
Milad Shadman ◽  
Gustavo Omar Guarniz Avalos ◽  
Segen F. Estefen
Author(s):  
Ratanak So ◽  
Asher Simmons ◽  
Ted Brekken ◽  
Kelley Ruehl ◽  
Carlos Michelen

WEC-Sim (Wave Energy Converter-SIMulator) is an open-source wave energy converter (WEC) code capable of simulating WECs of arbitrary device geometry subject to operational waves. The code is developed in MATLAB/Simulink using the multi-body dynamics solver SimMechanics, and relies on Boundary Element Method (BEM) codes to obtain hydrodynamic coefficients such as added mass, radiation damping, and wave excitation. WEC-Sim Version 1.0, released in Summer 2014, models WECs as a combination of rigid bodies, joints, linear power take-offs (PTOs), and mooring systems. This paper outlines the development of PTO-Sim (Power Take Off-SIMulator), the WEC-Sim module responsible for accurately modeling a WEC’s conversion of mechanical power to electrical power through its PTO system. PTO-Sim consists of a Simulink library of PTO component blocks that can be linked together to model different PTO systems. Two different applications of PTO-Sim will be given in this paper: a hydraulic power take-off system model, and a direct drive power take-off system model.


Author(s):  
Yi-Hsiang Yu ◽  
Ye Li ◽  
Kathleen Hallett ◽  
Chad Hotimsky

This paper presents a recent study on the design and analysis of an oscillating surge wave energy converter (OSWEC). A successful wave energy conversion design requires balance between the design performance and cost. The cost of energy is often used as the metric to judge the design of the wave energy conversion (WEC) system, which is often determined based on the device’s power performance; the cost of manufacturing, deployment, operation, and maintenance; and environmental compliance. The objective of this study is to demonstrate the importance of a cost-driven design strategy and how it can affect a WEC design. A set of three oscillating surge wave energy converter designs was analyzed and used as examples. The power generation performance of the design was modeled using a time-domain numerical simulation tool, and the mass properties of the design were determined based on a simple structure analysis. The results of those power performance simulations, the structure analysis, and a simple economic assessment were then used to determine the cost-efficiency of selected OSWEC designs. Finally, we present a discussion on the environmental barrier, integrated design strategy, and the key areas that need further investigation.


2017 ◽  
Vol 863 ◽  
pp. 175-182
Author(s):  
Yi Ming Zhu ◽  
Zi Rong Luo ◽  
Zhong Yue Lu ◽  
Jian Zhong Shang

This paper proposed a novel micro wave energy converter which can convert irregular wave energy into rotating mechanical energy, then into electrical energy. The device consists of an energy absorption part and an energy conversion part. In details, the blades are installed on the absorber circumferentially and averagely, which are capable of converting the vertical motion of the surface body to continuous rotation of the absorber and leading to a great increase in efficiency. A physical prototype was built to test the performance of the novel generator and optimize the design parameters. In the experiment part, a linear motion electric cylinder was used as the drive power to provide the heaving motion for the device. And the experiment platform was built for modeling a marine environment. Also, a data acquisition program was edited in Labview. Thus, the experiment analyzed the influence of amplitude, frequency, blade angle and resistance value to the output power, and then obtained the optimum parameters combination which can maximize the value of the output power. The result will provide reference for the device’s further application.


2021 ◽  
Vol 4 (2) ◽  
pp. 37-45
Author(s):  
Aldo Ruezga ◽  
José M. Cañedo C. ◽  
Manuel G. Verduzco-Zapata ◽  
Francisco J. Ocampo-Torres

A single-body point absorber system is analysed to improve its power absorption at a finite water depth.  The proposed wave energy converter consists of a single floating body coupled to a direct-drive power take-off system placed on the seabed. The structure of a cylindrical buoy with large draft is changed by a single body composed of three structures rigidly coupled, reducing its volume and improving its frequency-dependent hydrostatic parameters that are obtained through a numerical analysis tool called NEMOH. The undamped natural frequency of the oscillating system is tuned to a specified wave period and the performance of the WEC system is obtained assuming a linear Power Take-Off system. In time domain, the performance of the WEC device is carried-out under a regular (sinusoidal) and irregular incident wave profile. Comparing the performance of the WEC system using the cylindrical and the proposed buoy outcomes that the system with the proposed buoy is able to absorb more energy from incident waves with a wider frequency range, whereas the oscillating system is kept as simple as possible.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4201 ◽  
Author(s):  
George Lavidas ◽  
Francesco De Leo ◽  
Giovanni Besio

Coastal resilience is often achieved by traditional civil engineering projects, such as dikes and breakwaters. However, given the pressing nature of Climate Change, integrating energy converters in “classical” structures can enhance innovation, and help in pursuing decarbonisation targets. In this work, we present an alternative for integrating a wave energy converter at a vertical wall breakwater, following past successful projects. Our approach is based on a high spatio-temporal wave dataset to properly quantify expected energy production, but also focus on the hours for which other time-dependent renewables cannot produce, i.e., solar. Our analysis evaluates the power performance and assesses the economic parameters and viability of the proposed installation. Our integrated solution shares the main capital with the breakwater and can produce from 390 MWh–2300 MWh/year, displacing more than 1760 Tn of CO2 annually. In addition to power generated, we estimated the payback period for most cases being approximately 10–15 years, but when accounting avoided oil CO2 emissions, the installation is highly attractive with payback in less than 9 years, with favourable financing indicating 3.4 years.


2019 ◽  
Vol 26 (3) ◽  
pp. 107-114
Author(s):  
Esmaeil Homayoun ◽  
Hassan Ghassemi ◽  
Hamidreza Ghafari

Abstract This study deals with a new concept of near-shore combined renewable energy system which integrates a monopile wind turbine and a floating buoy with heave-type wave energy converter( WEC). Wave energy is absorbed by power-take-off (PTO) systems. Four different shapes of buoy model are selected for this study. Power performance in regular waves is calculated by using boundary element method in ANSYS-AQWA software in both time and frequency domains. This software is based on three-dimensional radiation/diffraction theory and Morison’s equation using mixture of panels and Morison elements for determining hydrodynamic loads. For validation of the approach the numerical results of the main dynamic responses of WEC in regular wave are compared with the available experimental data. The effects of the heaving buoy geometry on the main dynamic responses such as added mass, damping coefficient, heave motion, PTO damping force and mean power of various model shapes of WEC in regular waves with different periods, are compared and discussed. Comparison of the results showed that using WECs with a curvature inward in the bottom would absorb more energy from sea waves.


2021 ◽  
Author(s):  
Hainan Xia ◽  
Xiangnan Wang ◽  
Hao Chang ◽  
Yuanfei Zhang ◽  
Qiang Li ◽  
...  

This paper discusses the energy matching problem between wave energy input and generator power output, in the power performance assessment for the energy storage type of wave energy converter. Under the small wave condition, the power performance of the energy storage type of wave energy converter is researched. The site test data processing method is analyzed, and the calculation method of the average conversion efficiency and the annual energy production are optimized. The results show that the optimized power performance analysis method can more accurately assess the power performance matrix of the wave energy converter, and improve the calculation accuracy of the average conversion efficiency and the annual energy production of the wave energy converter. The research results provide an effective method for more scientific and accurate evaluation of power performance indexes of the energy storage type of wave energy converters.


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