Patent Award!
Indeximate are really pleased to report that one of their earliest works, a patent for establishing the health of subsea power cables has been granted in the UK in the closing days of 2024.
This patent is really foundational for Indeximate and is at the core of two of our health metrics EM1 & EM2 – EM being ElectroMechanical in this respect.
What the patent does is establish the link between the measurable vibration caused by flow of power that we extract from the cable with the state of the cable, particularly the armour.
Put simply – the electrical forces present within the cable between the conductors are repulsive and the overall geometry is maintained by the helical twist and the effect of the armour holding the cable together. The has polar symmetry around its axis and all should be balanced and harmonius. If the cable degrades (e.g. the armour is cut or weakned) this geometry is disrupted and this symmetry is lost. What is amazing is that we can measure these effects with fibre sensing – Distributed Acoustic Sensing is sensitive enough to pick up the Possion Ratio induced extension of the fibre caused by the current flowing within the cable! That’s one step but taking meaning from the measurements and extracting a metric that we can use over widely varying conditions and amongst a background of other overlapping contributions is harder. This is where our Indeximation and the Scattersphere comes in – it allows us to profile this metric over extended time periods.
We can extract both meaningful metrics to quantify the health of the cable in this way but also then to monitor how this changes over time.
Our two formulations (EM1 & EM2) provide us with metrics to monitor the state of the armour (EM1) and also the radial stiffness (EM2). These are two of the family of health indicators we provide and of course co-location is further evidence of problems afoot.
We deploy EM1 and EM2 on all jobs featuring three phase AC current. A DC version is in development. This is a great step forward in subsea power cable health monitoring and our goal towards preventing subsea cable failure
Read more about it on it in its published form or delve into our micro learnings for a longer discussion and see some data samples.
