'Long power cables: exposing incipient faults and optimizing performance using extra-long fibre optic distributed temperature monitoring'
9th International Conference on Insulated Power Cables Jicable'15 - Versailles 21-25 June, 2015 C3.4
Monitoring the temperature of power cables continuously all along their length provides condition monitoring and the opportunity for cable performance optimization using dynamic cable rating. However critical infrastructures being built or planned for the coming years, such as distant offshore wind farms (more than 60 km from the coast), ambitious interconnector projects and the growing preference for undergrounding require high performance, efficient asset management with reliable condition monitoring, whilst their length challenges the distance limits of existing temperature monitoring techniques.
At the same time monitoring the temperature of cables is becoming more critical due to the potential risks from:
Distributed temperature monitoring using fiber optic-based distributed sensing contributes to the safe and efficient operation of many onshore transmission cables and subsea cables. Extending these benefits cost effectively to longer array, export, interconnector and onshore transmission cables can be met using Brillouin-based sensing, which has demonstrated distributed sensing capabilities over more than 300 km from one interrogator, while maintaining temperature measurement performance in terms of both spatial and temperature resolution.
This paper, referring to proprietary research and supported by several Case Studies shows how Brillouin distributed monitoring can be configured from a single interrogator or using remote switch operation, amplifiers and repeaters to provide cost effective temperature monitoring of long cables, on and offshore. Case studies includes the monitoring of an interconnector, long onshore cable and wind farm export cables such Walney Offshore Windfarm 1 & 2 (>50 km), Greater Gabbard Offshore Windfarm (> 65km), London Array Offshore Windfarm (> 70km).