Regulation mechanism of porous structures on flashover performances: combined effect of hindering collision ionization and corona stabilization

The microscopic morphology is recognized as one of the key factors affecting the surface flashover strength, but the effect of nanoscale morphology is rarely investigated. In this paper, a novel strategy, namely, porous structural material was presented to improve the flashover strength, and porous nylon membranes with pore diameter from 100 nm to 5000 nm were used to explore the influence of nano-scale porous morphology on the flashover strength. The regulation mechanism of porous structures on flashover performances were explored through the analysis of potential scanning, partial discharge measurement, corona and flashover optical photos. The results indicated that the flashover strength under both AC and DC voltages could be significantly improved by the porous morphology, with a maximum increment of higher than 100%. It is believed that the improved flashover strength is attributed to the combined effect of hindering collision ionization and corona stabilization of porous structures. The present research provides a new insight for improving the surface insulation performance.