Analytical Research on Energy Conversion Characteristic of a Kind of Point Absorber Wave Energy Device

This paper summarizes the modeling and testing that was performed to integrate a point-absorber type Wave-Energy Converter (WEC) within the WindFloat hull. The WindFloat is a floating structure supporting a very large (>5MW) wind turbine. By adding a wave-energy device to the structure, one can improve the overall economic cost of the project, since both the mooring system and power infrastructure are shared. For the device analyzed here, the modeling is first described and then the Motion Response Amplitude Operators (RAOs) are computed. From these motion responses, the theoretical mechanical power available is calculated. The power values depend on empirical coefficients that need to be confirmed through model testing in the lab. The hydrodynamic forces on each device are often dependent on the interference between the device and the hull, the mooring, and the non-linear effects which are challenging to model. Therefore, these forces are approximated using a Morrison-type formulation in the numerical models. The empirical values for drag coefficients, damping coefficients, and stiffness coefficients in this report are validated against model tests, which are also described.

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Development of a novel point absorber in heave for wave energy conversion

Renewable Energy ◽

10.1016/j.renene.2013.08.028 ◽

2014 ◽

Vol 65 ◽

pp. 183-191 ◽

Cited By ~ 22

Author(s):

Dinh Quang Truong ◽

Kyoung Kwan Ahn

Keyword(s):

Energy Conversion ◽

Wave Energy ◽

Wave Energy Conversion ◽

Point Absorber

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The MBARI-WEC: a power source for ocean sensing

Journal of Ocean Engineering and Marine Energy ◽

10.1007/s40722-021-00197-9 ◽

2021 ◽

Author(s):

Andrew Hamilton ◽

François Cazenave ◽

Dominic Forbush ◽

Ryan G. Coe ◽

Giorgio Bacelli

Keyword(s):

Frequency Domain ◽

Wave Energy ◽

Autonomous Underwater Vehicles ◽

Domain Model ◽

Monterey Bay ◽

Hydrodynamic Models ◽

Energy Device ◽

Linear Frequency ◽

Point Absorber ◽

Wave Energy Converters

AbstractInterest in wave energy converters to provide autonomous power to various ocean-bound systems, such as autonomous underwater vehicles, sensor systems, and even aquaculture farms, has grown in recent years. The Monterey Bay Aquarium Research Institute has developed and deployed a small two-body point absorber wave energy device suitable to such needs. This paper provides a description of the system to support future open-source access to the device and further the general development of similar wave energy systems. Additionally, to support future control design and system modification efforts, a set of hydrodynamic models are presented and cross-compared. To test the viability of using a linear frequency-domain admittance model for controller tuning, the linear model is compared against four WEC-Sim models of increasing complexity. The linear frequency-domain model is found to be generally adequate for capturing system dynamics, as the model agreement is good and the degree of nonlinearity introduced in the WEC-Sim models is generally less than 2.5%.

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