Detection of corona and dry-band arc discharges on nano-composite epoxy insulators using RF sensing

RF radiation due to corona and dry-band arc discharges have been observed using an antenna. Variations in radiated energy were observed due to change in the distance between two water droplets, the contact angle and the volume of the droplets, and the condition of the insulator surface. Changes in the frequency spectrum within the 800 MHz{900MHz and 1.25 GHz{1.4 GHz frequency bands have been used to identify the transition from corona discharge to dry- band arc discharge. The 800 MHz{900MHz emission band has also been used to monitor the condition of the insulator. These ¯ndings highlight the potential for RF sensing in the identi¯cation of partial discharges and insulator condition monitoring