A self-consistent dynamic model allowing the prediction of ac discharge activities leading to flashover on ice-covered insulator surface is presented. This model takes into account the effects of a number of parameters including insulator geometry and applied water conductivity. The instantaneous variations of major parameters are discussed in order to develop a sequential time-dependent simulation of the flashover. The temporal evolution of arc current and axial arc velocity are determined in a consistent manner. The critical flashover voltage characteristics, as a function of surface conductivity, insulator length, and insulator diameter, calculated by the model are quite satisfactory when compared to the experimental results from empirical models reported in the literature.
A dynamic model for predicting dc arc behavior and critical flashover voltage of ice-covered insulating surfaces is presented. The model takes into consideration insulating geometry, pre-contamination level, and characteristics of ice layers. Assuming arc behavior as a time dependant impedance, it is possible to determine various arc characteristics such as time histories of leakage currents, potential gradient, channel radius, trajectory, propagation velocity and the energy injected into the zones free of ice (also called air gaps). The simulated results provided by the model are in agreement with those obtained experimentally using a simplified ice-covered cylinder as well as a short string of five IEEE standard porcelain suspension units covered with artificial ice.Index Terms -Dynamic model, dc arc, leakage current, outdoor insulators, flashover voltage, atmospheric icing.1070-9878/1/$17.00 0 2003 IEEE
Absfrad-This paper investigates the feasibility of using a dynamic arc modeling to predict flashover of ice-covered insulators. The proposed mathematical model includes the successive propagation of the arc. The input data of this selfconsistent mathematical model are the insulator geometry, the ice layer characteristics andlor properties, the applied voltage and some initial values. The computed results are compared to the minimum flashover voltage measured experimentally on a IEEE standard insulator strings. The results indicate the feasibility of assessment of icing severity and flashover prediction, using the proposed model. Index Term-insulators, atmospheric icing, leakage current, flashover voltage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.