Pollution flashover performance of 220 kV glass insulator strings covered with incomplete spraying PRTV coatings

The PRTV coating materials had perfect performance in antipollution flashover for porcelain and glass insulators because of the surface hydrophobicity. Usually, the whole strings of insulators were coated with PRTV coatings in engineering application. In order to reduce the consumption of materials, a way of incomplete spraying PRTV coatings was mentioned in this paper. And the pollution flashover performance of 220kV glass insulator strings covered with incomplete spraying PRTV coatings were investigated by artificial contamination test under AC voltages. Conclusions were obtained that the flashover voltage can be enhanced greatly by covering PRTV coatings and the leakage current can be reduced. Compared with the whole string of insulators covered with PRTV coatings, the outdoor insulation performance showed little difference for 220kV glass insulator strings covered with incomplete spraying coatings. This work can provide theoretical support for external insulation´s maintenance and design of 220kV AC transmission lines.