Elvia is testing a new technology for faster fault location in medium-voltage cables (11-22kV). Sensors detecting partial discharge (PD) make it possible to identify weak points in the grid (e.g. weakened isolation material).

This allows for replacing cable segments before actual faults occur. Additionally, the system indicates the fault location right after a fault has occurred, which saves a lot of time in the fault handling process.

The technology’s ability to identify fault locations has been verified several times, with an accuracy of 1%. Identification of weak points in the grid that have not yet caused a fault has not been verified to this point, although the principle was demonstrated earlier in a Dutch study. The reason for this is still unclear and will be investigated.

We will also analyse if the PD-measurements can be used for other purposes, e.g. dynamic line rating (dynamic calculations of the cable’s current carrying capacity), based on the signal speed between the sensors.

Publications:

• Pilot "Smart Cable Guard" report  (in Norwegian)
• Pilot Results
• Pilot Innovations

Contact person:

• , Elvia