Moisture Monitoring in Long-Range High-Voltage Cable Systems

Purpose and goal:

We have evaluated the feasibility of developing and implementing fiber optic moisture measurement in power cables, as well as in joints and terminations. The fundamental requirements for this are met, and the study has provided insights into which applications to target, which partners are necessary partners for further development, and what the remaining technical uncertainties are.

In the next step, we need to involve end-users and investigate the repeatability of the technology over the expected lifespan of the infrastructure, approximately 40-years. Expected results and effects:

The feasibility study has offered understanding regarding the most relevant applications and how the data can be beneficial in those contexts. We have demonstrated the feasibility through experiments and literature research, and we identified knowledge that need to be acquired, such as the practical lifespan of the sensors. We also have a plan for further development of the identified applications.

Ultimately, we believe that moisture measurement has potential as a tool for predictive maintenance of power infrastructure. Approach and implementation:

The project was a collaboration between RISE and NKT Cables and the activities were planned together. NKT investigated how sensors can be integrated into the products, in which applications it is relevant and possible, and which partners would be appropriate to include in the future. In the first part of the project, a literature study was made and a compilation of materials suitable for the humidity sensor.

Then prototype sensors were manufactured which were evaluated in two climate chamber tests approximately two weeks in duration.