The Reversibility Of The Characteristics Of Gas-filled Surge Arresters

This paper presents a consideration of the reversibility of the characteristics of gas filled surge arresters (GFSA) under exploatation conditions. Several commercial GFSA types were examined. In order to conduct the experimental part of this work, an automatic measurement system was developed, enabling large series of neasurements. The measured values included the DC breakdown voltage, the pulse breakdown voltage and the emission current. The obtained results were statistically treated by testing their compliance with certain theoretical random variable distributions and the corresponding parameters were estimated. The belonging of the measured values to the same random variable was investigated through statistical tests. By employing the "area law", a numerical program for determining the pulse shape characteristics was developed. All the results obtained were explained theoretically, based on the theory of electrical discharge at small pd Values (pressure x inter-electrode gap). A theoretical consideration was undertaken on the discharge mechanism influence (Towsend and streamer) on the reversibility of the GFSA characteristics. On the basis of theoretical and experimental results, a conclusion was drawn upon the conditions under which the GFSA characteristics can be consider as reversible during exploatation. Certain suggestions on the possibilities of improving the GFSA reversibility characteristics were also outlined.