Focusing on the influence of fine metal particles on the insulation characteristics of outdoor insulators, spherical micrometer-level iron powders were used to represent fine metal particles of different parameters on a polymer insulator specimen surface. Dynamic movement and lift-off behavior of fine particles, as well as the triggered surface discharges under AC voltage were investigated in a...

When assessing extremely low breakdown probabilities for selfrestoring gaseous insulation by automatic equipment, it is often more important to keep the actual number of breakdowns low, rather than to control the total number of voltage applications. In order to achieve this, one might use an inverse sampling procedure that commences the voltage application at a very low level, followed by appl...

A controlled fire burner was constructed where various natural vegetation species could be used as fuel. The burner was equipped with thermocouples to measure fuel surface temperature and used as a cavity for microwaves with a laboratory quality 2-port vector network analyzer to determine electrical conductivity from S-parameters. Electrical conductivity for vegetation material flames is import...

This work attempts to apply an artificial neural network in order to estimate the critical flashover voltage on polluted insulators. The artificial eural network uses as input variables the following characteristics of the insulator: diameter, height, creepage distance, form factor and equivalent alt deposit density, and estimates the critical flashover voltage. The data used to train the netwo...

Through this paper work we have analyzed the effect of different contaminants on the flashover by creating artificial pollution condition, considering the natural condition where more than one salt as contaminant deposits on the surface of insulator at a time, under the wet condition that cause flow of highly leakage current, that leads to flashover. We choses the mixture of different salts, so...

Problem statement: The phenomenon of flashover in polluted insulators has been continued by the study of the characteristics of contaminating layers deposited on the surface of insulators in high voltage laboratories. In the literature, Experimental investigations have been carried out on a real insulator or a flat plate model of insulators under high voltage application. This study proposed th...

Abstract: This paper descirbes leakage current characters and discharge phenomenon of outdoor insulators both in the lab and in the field. The results are hoped to be used for online monitoring of the contamination levels. The following contents are introduced in the paper: leakage current monitoring systems, relationships between leakage current and discharge phenomenon, flashover prediction m...

A comprehensive methodology has been developed for obtaining and using smoke toxicity data for fire hazard analysis. This bench-scale method can simulate diverse fire conditions and identify extremely toxic smoke under both pre- and post-flashover conditions. However, incidence data show that most of the fire deaths in the U.S. occur outside the room of fire origin from smoke and toxic gases th...

This work presents the effect of room temperature vulcanized (RTV) silicone rubber coating on cap and pin type porcelain insulator under ac (50Hz) flashover voltage (KV). Describes experimental results obtained for improvement of porcelain insulator removed from 33kV overhead transmission line at Aswan, Egypt after 28 years of service. Also, this study briefly surveys the environmental contamin...

Perhaps no single area of insulator behavior has fascinated researchers more so than predicting flashover under contaminated conditions. For traditional porcelain and glass insulators, there is a large body of literature published that includes both theoretical models and experimental tests to simulate this interesting and practically important aspect of insulator performance. Yet there still s...