Characteristics of creeping discharge developed in narrow gap on a filamentous backside electrode

We describe the characteristics of a creeping discharge developed in a narrow gap with a backside electrode, under microsecond pulse voltage application. In a gas mixture of 3% SF 6 in N 2 , the flashover voltage at pressures of 0.2 and 0.3 MPa decreased by approximately 5% compared to that of 0.1 MPa when using both a filamentous straight backside electrode and a filamentous curved backside electrode. V‐characteristics with decreased flashover voltage were obtained with SF 6 mixtures in N 2 . We obtained V‐characteristics of the flashover voltage for SF 6 concentrations in the range of D =3 to 100% for a filamentous backside electrode. The flashover voltages obtained with a filamentous straight backside electrode were higher than those obtained with a filamentous curved backside electrode. From corona observation using an ultra‐high‐speed camera, it was found that the flashover is generated along the backside electrode. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(1): 1–9, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20955