State-Space Approximation of Convolution Term in Time Domain Analysis of a Raft-Type Wave Energy Converter

Changhai Liu, Qingjun Yang and Gang Bao
Additional contact information
Changhai Liu: Department of Fluid Control and Automation, Harbin Institute of Technology, Harbin 150001, China
Qingjun Yang: Department of Fluid Control and Automation, Harbin Institute of Technology, Harbin 150001, China
Gang Bao: Department of Fluid Control and Automation, Harbin Institute of Technology, Harbin 150001, China

Energies, 2018, vol. 11, issue 1, 1-22

Abstract: Two methods, frequency domain analysis and time domain analysis, are widely applied to modeling wave energy converters (WECs). Frequency domain analysis can evaluate the performance of WECs quickly and efficiently, while it refers to a linear model. When it comes to investigations on nonlinear characteristics of the power take-off (PTO) unit of WECs or control for improving the WECs’ performance, time domain analysis based on a state-space approximation for the convolution term is more desirable. In this paper, a state-space approximation of the convolution term in a time domain analysis of a raft-type WEC consisting of two rafts and a PTO unit is presented. The state-space model is identified through regression in the frequency domain. Verification of such a type of time domain analysis is conducted by comparison of its simulation results with those calculated by using a frequency domain analysis, and there is a good agreement. Finally, the effects of PTO parameters, wave frequency, surge and heave motions of the joint, and quadratic damping PTO on the power capture ability of the raft-type WEC are investigated.

Keywords: raft-type wave energy converter (WEC); power take-off (PTO); frequency domain; time domain; power capture ability; capture width ratio (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2018
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (3)

Downloads: (external link)
https://www.mdpi.com/1996-1073/11/1/169/pdf (application/pdf)
https://www.mdpi.com/1996-1073/11/1/169/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:11:y:2018:i:1:p:169-:d:126316

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().