Distributed Optical Sensing Platform for Subsea Cable Monitoring and Fault Detection

In offshore wind energy production, operational expenditures account for approx. 25% of the levelized cost of energy (LCOE). Reducing maintenance costs would allow offshore wind energy to compete more favorably with alternative forms of power generation. Structural health monitoring (SHM) and fault detection systems hold the promise of reducing operational costs by allowing a transition from schedule-based to condition-based maintenance schedules. A key component of offshore wind farms is the power transmission system, including subsea power transmission cabling. This Phase-I project seeks to establish feasibility of continuous- wave, interferometric, distributed fiber-optic sensing technologies for monitoring of power transmission cabling for near- and far-offshore wind farms. Approaches for extending sensing length of existing and novel distributed sensing technologies will be explored. In this effort, we propose to assemble a distributed sensing prototype interrogator, to investigate improvements to existing and novel approaches for long-length distributed sensing, to conduct testing to establish proof-of-concept of the subject technologies, and to formulate a further research and development plan for a subsequent Phase-II effort. Optical sensor technologies and demodulation techniques will be analyzed, implemented, and iterated upon in an effort to demonstrate applicability of the approach to far-offshore power transmission cable SHM and fault detection. Increasing reach (i.e. sensing length) of high-performance distributed fiber-optic sensing technology will positively affect application of the technology to markets such as aerospace, defense, oil & gas, and linear asset monitoring. In these markets, improved SHM capability leads to improvements in efficiency, safety, performance, and operational lifetimes of monitored systems.