DC partial discharge and flashover characteristics and charging activity on solid insulator in air

DC partial discharge (PD) characteristics with PD inception voltage and PD activities are measured depending on the different electrode gap lengths and electrode configurations, and with and without solid insulators as PMMA. The charges deposited on solid insulators are measured by surface potential measurement systems. In this paper, it was concluded that the DC-PD inception and flashover voltages are quantitatively determined by the DC applied electric field and PD space charges and deposited surface charge distributions, depending on the positive and negative DC polarity of applied voltages.