Pseudo-spectral control of a novel oscillating surge wave energy converter in regular waves for power optimization including load reduction
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
The aim of this study is to describe a procedure to maximize the power-to-load ratio of a novel wave energy converter (WEC) that combines an oscillating surge wave energy converter with variable structural components. The control of the power-take-off torque will be on a wave-to-wave timescale, whereas the structure will be controlled statically such that the geometry remains the same throughout the wave period. Linear hydrodynamic theory is used to calculate the upper and lower bounds for the time-averaged absorbed power and surge foundation loads while assuming that the WEC motion remains sinusoidal. Previous work using pseudo-spectral techniques to solve the optimal control problem focused solely on maximizing absorbed energy. This work extends the optimal control problem to include a measure of the surge foundation force in the optimization. The objective function includes two competing terms that force the optimizer to maximize power capture while minimizing structural loads. A penalty weight was included with the surge foundation force that allows control of the optimizer performance based on whether emphasis should be placed on power absorption or load shedding. Results from pseudo-spectral optimal control indicate that a unit reduction in time-averaged power can be accompanied by a greater reduction in surge-foundation force.
- Research Organization:
- National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- Sponsoring Organization:
- NREL Laboratory Directed Research and Development (LDRD); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Wind and Water Technologies Office (EE-4W); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Water Power Technologies Office
- Grant/Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1357747
- Alternate ID(s):
- OSTI ID: 1415660
- Report Number(s):
- NREL/JA-5000-65123
- Journal Information:
- Ocean Engineering, Vol. 137, Issue C; ISSN 0029-8018
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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