Preliminary laboratorial determination of the REEFS novel wave energy converter power output

2018 ◽  
Vol 122 ◽  
pp. 654-664 ◽  
Author(s):  
J.P.P.G. Lopes de Almeida ◽  
B. Mujtaba ◽  
A.M. Oliveira Fernandes
Keyword(s):  
Wave Energy ◽  
Power Output ◽  
Wave Energy Converter ◽  
Energy Converter

Numerical Simulation and Optimization of a Wave Energy Converter for the Izu Islands Sea in Japan

2014 ◽  
Author(s):  
Takeshi Kamio ◽  
Makoto Iida ◽  
Chuichi Arakawa
Keyword(s):  
Numerical Simulation ◽  
Wave Energy ◽  
Power Output ◽  
Test Site ◽  
Wave Energy Converter ◽  
Complex Conjugate ◽  
Maximum Output ◽  
Energy Converter ◽  
Simulation And Optimization ◽  
Izu Islands

The purpose of this study is the numerical simulation and control optimization of a wave energy converter to estimate the power at a test site in the Izu Islands. In Japan, ocean energy is once again being seriously considered; however, since there are many inherent problems due to severe conditions such as the strong swells and large waves, estimations are important when designing such devices. The numerical simulation method in this study combines the wave interaction analysis software WAMIT and an in-house time-domain simulation code using the Newmark-β method, and introduces approximate complex-conjugate control into the code. The optimized parameters were assessed for a regular sine wave and an irregular wave with a typical wave spectrum. With the optimized parameters, average and maximum output power were estimated for the observed wave data at the test site. The results show a more than 100 kW average power output and a several times larger maximum power output.

Evaluating Constant DC-Link Operation of Wave Energy Converter

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Rickard Ekström ◽  
Venugopalan Kurupath ◽  
Cecilia Boström ◽  
Rafael Waters ◽  
Mats Leijon
Keyword(s):  
Wave Energy ◽  
Power Output ◽  
Wave Energy Converter ◽  
Damping Factor ◽  
Energy Converter ◽  
Sea State ◽  
Voltage Level ◽  
Electromagnetic Damping ◽  
Point Of Common Coupling ◽  
Common Coupling

A wave energy converter (WEC) based on a linear generator and a point-absorbing buoy has been developed at Uppsala University. Interconnecting an array of WECs in parallel requires a point of common coupling, such as a common dc-bus. The dc voltage level seen by the generator is directly linked to the electromagnetic damping of the generator. A lower dc-level results in a higher damping factor and is important for increased absorption of the wave power. The drawback is increased losses in generator windings and cable resistance. There will be an optimal dc-level for maximum power output. This is a function of not only generator and buoy characteristics, but the current sea state. Experimental results of the full-scale system have been carried out, and used as validation of a simulation model of the system. The model is then used to evaluate how the dc-level seen by the generator influence the power output. The results indicate that higher dc-levels should be used at higher sea states, and power output may vary by up to a factor five depending on which dc-level is chosen.

Power Output Performance and Smoothing Ability of an Oscillating Water Column Array Wave Energy Converter

2013 ◽  
Author(s):  
Keith O’Sullivan ◽  
Jimmy Murphy ◽  
Dara O’Sullivan
Keyword(s):  
Time Series ◽  
Water Column ◽  
Wind Turbines ◽  
Wave Energy ◽  
Power Output ◽  
Output Signal ◽  
Electrical Power ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter

This paper presents the physical model testing results of a floating oscillating water column (OWC) array wave energy converter (WEC) and the power smoothing ability inherent in the OWC chamber arrangement in the structure. The device can be categorised as a very large floating structure (VLFS) with structure dynamics which may make it a suitable device on which to mount wind turbines. It incorporates 32 individual OWC chambers in a “V” shaped arrangement such that there is a phase-lag between successive wave crests in the OWC chambers as an individual wave passes the structure. This OWC array was tested in both monochromatic and panchromatic unidirectional wave fields and the motion response amplitude operators (RAO) have been calculated. The time series of absorbed power from panchromatic waves was then used as input to a simple Well’s turbine power take-off (PTO) Simulink model to estimate the electrical power produced by each chamber and the additive power produced by the 32 OWC’s. A simple control law of optimum speed of the generator was used for these simulations. The time series of total electrical power from the 32 chambers was compared to the time series of an individual chamber and the standard deviation of the signals were also compared. The OWC array achieved a much smoother power output signal than a device with one chamber. Further smoothing of the output signal is possible by increasing the inertia of the turbine however, this may have implications for the mean efficiency of the power train. A preliminary design of the Well’s turbine is included, both in terms of mechanical parts and generator rating. This paper focusses on the power absorption and motion performance of the device and discusses the potential for the addition of wind turbines.

scholarly journals Design and Construction of a Novel Simple and Low-Cost Test Bench Point-Absorber Wave Energy Converter Emulator System

Inventions ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 20
Author(s):  
Ephraim Bonah Agyekum ◽  
Seepana PraveenKumar ◽  
Aleksei Eliseev ◽  
Vladimir Ivanovich Velkin
Keyword(s):  
Wave Energy ◽  
Power Output ◽  
Test Bench ◽  
Low Cost ◽  
Wave Energy Converter ◽  
Real Point ◽  
Energy Converter ◽  
Point Absorber ◽  
Laboratory Conditions ◽  
Wave Generator

This paper proposed a test bench device to emulate or simulate the electrical impulses of a wave energy converter (WEC). The objective of the study is to reconstruct under laboratory conditions the dynamics of a WEC in the form of an emulator to assess the performance, which, in this case, is the output power. The designed emulator device is programmable, which makes it possible to create under laboratory conditions the operating mode of the wave generator, identical to how the wave generator would work under real sea conditions. Any control algorithm can be executed in the designed emulator. In order to test the performance of the constructed WEC emulator, an experiment was conducted to test its power output against that of a real point-absorber WEC. The results indicate that, although the power output for that of the real WEC was higher than the WEC emulator, the emulator performed perfectly well. The relatively low power output of the emulator was because of the type of algorithm that was written for the emulator, therefore increasing the speed of the motor in the algorithm (code) would result in higher output for the proposed WEC emulator.

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