Critical partial discharge in cable termination revealed without any service disruptions

During a online PD survey we found severe PD activity on several cable circuits in a substation. Through the analysis, the activity were located to be in one of the cable circuits.

The terminations were dissected in a effort to find the root cause. Due to incorrect installation, severe PD had over time degraded the XLPE insulation. The field control had been installed incorrect and this have caused wrong distribution of the electrical field at the end of the semicon.

On the outside the terminations looked fine and gave no reason for concern.

With PD measurements we find the actual condition on your high voltage assets, without service interruption.

In the same substation we could reveal PD activity at the disconnector and the busbar bushing