Fibre optic sensors for cable lifetime performance monitoring

Project Description:

The research project is in partnership with Offshore Renewable Energy (ORE) Catapult. The PhD directly addresses sector needs to understand power cable sensor design.

Failure and repair of array and export cables represent one of the largest costs for wind farm operators and are a focus for extensive research interest. There are varied root causes for cable failures, including stresses caused by seabed movement and free spans, overheating as a result of excess burial depth and excessive curvature during installation and burial, but these are poorly understood.

Fibre optic sensing schemes are an attractive solution for through-life distributed measurement of temperature and strain, making use of the existing optical fibres embedded in the cables for communication purposes. However, there are limitations on the spatial resolution and the resolution of temperature, strain and curvature that can be achieved. This PhD will consider a range of fibre optic sensing schemes and associated interrogation techniques to assess their capabilities in measuring temperature, strain and curvature when incorporated into different cable cross section structures.

A particular focus will be on improving spatial resolution and resolving strain/curvature in 2 dimensions; which is important for understanding cable loading but is not currently possible. The research will develop a sensing approach, possibly combining distributed or discrete sensing schemes, to address the aforementioned issues. Research project activities will include modelling, design and fabrication of prototype sensors or sensing schemes and the cable structures needed to achieve the aims of the project. These potential solutions will be evaluated experimentally.