Investigations on post partial discharge charge decay in void using chopped sequence

Abstract

This paper describes a novel approach to investigating the mechanisms related to partial discharge dynamics. Applying the chopped sequence provided insight into the dielectric void and allowed post partial discharge charge decay phenomena to be investigated. The measurements were performed on specimens with an embedded void having three different wall dielectric materials: insulating paper, thermosetting insulation or cross-linked polyethylene. The quantitative approach offers greater information regarding the relationship between measured quantities on phase-resolved patterns and charge decay phenomena inside the void. The comparison of PD inception phase angles between continuous and chopped sequence was used as an indicator for calculation of internal charge time decay in the void. The precise calculation of time constant for various void wall materials was presented. The decaying charge resulted in the variation of the electric field from deposited and accumulated charges. The presented methodology may allow the void to be analyzed with greater clarity, offering the potential to assess various mechanisms such as charge neutralization and conduction.