Modeling partial discharge phenomena
George Callender, P. L. Lewin
Abstract
Measurements of partial discharge (PD) activity are a commonly used technique to diagnose the health of insulation material within high voltage plant. The definition of PD is relatively broad, it is generally defined as a localized or confined discharge within an insulating medium [1]. Due to the high electric breakdown strength of insulation materials, PDs typically occur within low density defects in the system. One family of defects which has received significant research attention is air-filled voids, typically spherical or cylindrical, surrounded by solid dielectric material. Experiments have typically used a `sandwich' technique to fabricate cylindrical voids, using three slabs of material with a circular hole drilled into the central slab. The slabs are then pressed together and placed between parallel plate electrodes. A common dielectric material used to fabricate cylindrical voids is LDPE [2]. By injecting air through a syringe before the curing process spherical voids have been fabricated in epoxy resins [3,4] and silicone rubber [5].