This video presents the measurement of partial discharges on a 25 kV AC 50 Hz.

The setup is:

  • a 25 kV AC 50 Hz generator with the possibility to have a manual or an automatic voltage ramp-up
  • a safety cabinet to place the DUT inside
  • the DUT is a 25 kV cable without internal shielding (copper or aluminium)
  • a steam generator to change and increase the humidity inside the safety cabinet
  • a eoSense converter of LF type (from 40 Hz to 30 MHz)
  • a ET5-air probe type (transverse and high sensitivity)
  • an oscilloscope

The main process is:

  • Voltage is slowly increased up to few kV ac
  • Detection of first partial discharges
  • Increase of the internal humidity using the steam generator
  • Increase of voltage
  • Visualisation of an increasing number of partial discharges