High ohmic earth fault
In one of the feeders of a primary substation located in a rural area, 17 incidents of recurring high ohmic earth faults (>8 kΩ) were registered over the course of about 1 hour.
A quick overview of the map identified a possible area as the source of the incidents. A team was dispatched to investigate the line going through the wooded area. At the scene, the team was able to quickly determine that an energy forest planted below the lines, had grown wild. At the slightest wind, the tops repeatedly touched the overhead line.
A trimming of the treetops in the energy forest was conducted and a potential outage prevented.