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Stochastic control of inertial sea wave energy converter.

Raffero M, Martini M, Passione B, Mattiazzo G, Giorcelli E, Bracco G - ScientificWorldJournal (2015)

Bottom Line: The response of the WEC (wave energy converter) is driven by the sea-surface elevation, which is modeled by a stationary and homogeneous zero mean Gaussian stochastic process.System equations are linearized thus simplifying the numerical model of the device.Results of this approach have been compared with the ones obtained with a linear spring-damper controller, highlighting the capability to obtain a higher value of mean extracted power despite higher power peaks.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanics and Aerospace Engineering, Polytechnic University of Turin, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.

ABSTRACT
The ISWEC (inertial sea wave energy converter) is presented, its control problems are stated, and an optimal control strategy is introduced. As the aim of the device is energy conversion, the mean absorbed power by ISWEC is calculated for a plane 2D irregular sea state. The response of the WEC (wave energy converter) is driven by the sea-surface elevation, which is modeled by a stationary and homogeneous zero mean Gaussian stochastic process. System equations are linearized thus simplifying the numerical model of the device. The resulting response is obtained as the output of the coupled mechanic-hydrodynamic model of the device. A stochastic suboptimal controller, derived from optimal control theory, is defined and applied to ISWEC. Results of this approach have been compared with the ones obtained with a linear spring-damper controller, highlighting the capability to obtain a higher value of mean extracted power despite higher power peaks.

No MeSH data available.


Frequency domain identification for the ISWEC floater: 4th order transfer function magnitude and phase.
© Copyright Policy - open-access
Related In: Results  -  Collection


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fig2: Frequency domain identification for the ISWEC floater: 4th order transfer function magnitude and phase.

Mentions: Figure 2 shows that it has been possible to find a transfer function able to describe the radiation frequency response function of the floater, with a sufficient approximation in the typical frequency range of the studied sea. The obtained transfer function is stable and responds to the required passivity criteria.


Stochastic control of inertial sea wave energy converter.

Raffero M, Martini M, Passione B, Mattiazzo G, Giorcelli E, Bracco G - ScientificWorldJournal (2015)

Frequency domain identification for the ISWEC floater: 4th order transfer function magnitude and phase.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4385674&req=5

fig2: Frequency domain identification for the ISWEC floater: 4th order transfer function magnitude and phase.
Mentions: Figure 2 shows that it has been possible to find a transfer function able to describe the radiation frequency response function of the floater, with a sufficient approximation in the typical frequency range of the studied sea. The obtained transfer function is stable and responds to the required passivity criteria.

Bottom Line: The response of the WEC (wave energy converter) is driven by the sea-surface elevation, which is modeled by a stationary and homogeneous zero mean Gaussian stochastic process.System equations are linearized thus simplifying the numerical model of the device.Results of this approach have been compared with the ones obtained with a linear spring-damper controller, highlighting the capability to obtain a higher value of mean extracted power despite higher power peaks.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanics and Aerospace Engineering, Polytechnic University of Turin, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.

ABSTRACT
The ISWEC (inertial sea wave energy converter) is presented, its control problems are stated, and an optimal control strategy is introduced. As the aim of the device is energy conversion, the mean absorbed power by ISWEC is calculated for a plane 2D irregular sea state. The response of the WEC (wave energy converter) is driven by the sea-surface elevation, which is modeled by a stationary and homogeneous zero mean Gaussian stochastic process. System equations are linearized thus simplifying the numerical model of the device. The resulting response is obtained as the output of the coupled mechanic-hydrodynamic model of the device. A stochastic suboptimal controller, derived from optimal control theory, is defined and applied to ISWEC. Results of this approach have been compared with the ones obtained with a linear spring-damper controller, highlighting the capability to obtain a higher value of mean extracted power despite higher power peaks.

No MeSH data available.