Parametric study of the dynamic motions and mechanical characteristics of power cables for wave energy converters
Journal
Journal of Marine Science and Technology (Japan)
Journal Volume
23
Journal Issue
1
Pages
10-29
Date Issued
2018
Author(s)
Abstract
A case study of a point-absorber wave energy converter (WEC) system is presented. The WEC system forms an array, with several WECs located around a central hub to which they are each connected by a short, free-hanging power cable. The objective of the study is to analyse the dynamic characteristics and estimate the fatigue life of the power cable which is not yet in use or available on the commercial market. Hence, a novel approach is adopted in the study considering that the power cable’s length is restricted by several factors (e.g., the clearances between the service vessel and seabed and the cable), and the cable is subject to motion and loading from the WEC and to environmental loads from waves and currents (i.e., dynamic cable). The power cable’s characteristics are assessed using a numerical model subjected to a parametric analysis, in which the environmental parameters and the cable’s design parameters are varied. The results of the numerical simulations are compared and discussed regarding the responses of the power cables, including dynamic motion, curvature, cross-sectional forces, and accumulated fatigue damage. The effects of environmental conditions on the long-term mechanical life spans of the power cables are also investigated. Important cable design parameters that result in a long power cable (fatigue) service life are identified, and the cable service life is predicted. This study contributes a methodology for the first-principle design of WEC cables that enables the prediction of cable fatigue life by considering environmental conditions and variations in cable design parameters. ? 2017, The Author(s).
Subjects
Cables
Dynamics
Fatigue damage
Fatigue of materials
Numerical models
Service vessels
Telecommunication cables
Wave power
Accumulated fatigue damage
Cross-sectional forces
Dynamic characteristics
Environmental conditions
Environmental parameter
Mechanical characteristics
Power cables
Wave energy converters
Wave energy conversion
Type
journal article