Flashover process analysis of non-uniformly polluted insulation surface using experimental design methodology and finite element method

Conclusions about flashover process of non-uniformly polluted insulating surface may be drawn widely on the basis of laboratory experimental studies. However, these conclusions could be supported by simulation results on the E-field stress distribution. This paper presents a study of the flashover voltage, the maximum E-field and the breakdown strength of the non-uniformly polluted insulating surface. Three parameters of pollution layer were taken into account: the conductivity, the length and the position. The experimental design methodology is adopted in this study. Parameters main and interaction effects have been evaluated using the variance analysis technique. Results show that the flashover process is mainly influenced by the length of pollution layer, however, the effect of conductivity is limited on the accelerating the flashover process, which in-turn reduces the breakdown strength. As conclusion, the simulation based on the finite element method combined with the experimental design methodology found to be very efficient tool to understand the flashover process of non-uniformly polluted insulating surface. The obtained information could be exploited to better understand the flashover process as well as to improve the insulation flashover testing standard under laboratory simulated conditions.