Application of Distributed Fiber-Optic Sensors in Energy Cables for Smart Grids Technology

Electricity demand is estimated to increase nearly 1000 TWh per year through to 2035; to keep up with this demand it follows the need to implement intelligent grid systems that require secure monitoring and control of the power transmission line. In this thesis it is analyzed the use of Distribute Fiber Optic Sensors (DFOS) for the application of power cable's monitoring and it is explained why this technology is proposed over the use of single point sensors. It is proposed the use of Fiber in Metal Tube (FIMT) for the distributed sensing of temperature and strain. Five different samples with different configurations are tested. To measure the fiber's response to the different stimuli an OBR and a laboratory custom benchtop OFDR setup are used to acquire the backscattered Rayleigh signature. These two type of interrogators allow for a very fine spatial resolution. It is firstly measured the response of the FIMT to unwinding, the strain profile are collected immediately after the straightening and in the following days. Afterward the fiber's response to temperature variation is measured, from the results of this experimental activity is possible to analyze the sample's sensitivity to temperature. Ultimately the results of the two experimental activities are analyzed to compare the different sample configurations and to see whether they can accurately detect the different stimuli.