Propagation Characteristic of Surface Discharge under AC Application Voltage

The propagation characteristic of surface discharge under the application of power-frequency AC voltage is the most fundamental characteristics should be studied. At the triple point in high voltage apparatus, surface discharge occurs easily. It is initiated by the propagation of a surface streamer, followed by a surface leader formation and final flashover phenomenon. It is of great importance to clarify the propagation characteristic of surface discharge under AC application voltage. In this paper, discharge propagation characteristics on the surface of a PMMA and PET pipe under AC voltage are investigated with a high speed video camera. The relation among the propagation length, the inception voltage and the phase angle was studied, and the following conclusions were obtained. The discharge is easy to occur under the negative polarity of AC voltage. For the discharge on the thin insulator pipe surface, the discharge is easy to propagate to a long distance; the relationship of the maximum length of discharge and the applied AC voltage can be expressed as an exponential equation.