An Investigation of Leakage Current and Partial Discharge ForVarious Overhead Insulators

Abstract

High voltage insulators used in various overhead forms are exposed to leakage current and partial discharge.
This work deals with different structure forms of insulator, such as (pin post, clamp top and tie top). These structures are applied in different tests, as covered and stripped states. The leakage current for these forms were measured by raising the insulator voltage to (5.25, 6.35, 7.57 kV) for covered and stripped state. Partial discharges were determined in covered and stripped state of these insulator forms using (straight and balanced detection method).
Pin post insulators have a leakage current and electric field larger than both clamp top and tie top. The clamp top and tie top insulator show almost the same value of leakage current measurements.
The stripped conductors always produce large partial discharge than covered conductor.
Key words: Leakage current, Insulator Materials, Partial discharge, stripped Insulator, Covered Insulator.