Withstand Voltage Characteristics Research Articles

AC withstand voltage characteristics of insulator string covered with snow

Results of an investigation into the withstand voltage characteristics of a UHV-class tension insulator string covered with snow are reported. AC withstand voltage tests were conducted in a testing room and at an exposure testing station constructed in a heavy snow area. For insulator strings up to 10 m long, the withstand voltage was almost roughly proportional to the length of the insulator string. The relations between the withstand voltage and the characteristics of the snow are reported. A design example for determining the length of the snow-covered string is presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Performance of Contaminated Bushing of UHV Transmission Systems

This paper describes the power-frequency contamination withstand voltage characteristics of a UHV bushing under light contamination condition. The withstand voltage of a UHV porcelain housing under light contamination condition was not in proportion to the effective length. On the other hand, the linear relation between the withstand voltage and the effective length was confirmed for the complete bushing up to the effective length of 12 m. Thus it was clarified that the withstand voltage under light contamination was favorably influenced by the inner components of the UHV bushing.

A Practical Study on Application of Semiconducting Glaze Insulators to Transmission Lines

This paper covers the results of investigations of the various electrical characteristics of 10-in porcelain suspension insulators with a semiconducting glaze. The runaway withstand voltage is shown almost proportional to the number of insulator units in a string. To get an almost uniform distribution along a string the impedance of the units should be lowered as the number of the units increases. Runaway withstand voltage characteristics under adverse condition and margin against working voltage are also examined. The performance of contaminated semiconducting glaze insulators under cold switch-on condition is quantitatively investigated.