Electric Field Modelling in Gas-Insulated Substation for Analysis of Conditions for Partial Discharge Phenomena

Abstract

The paper refers to diagnostics problems connected with the presence of partial discharges in gas-insulated substation. The basic stimulus for partial discharges generation is local, high value electric eld, greater than the inception one. The numerical simulations of the electric eld distribution in the part of the gas insulating system and in the vicinity of the metallic protrusion located on high voltage conductor are presented. Such defects are often present in SF6 insulated constructions and are the cause of a local increase of the electric eld. Theoretical analysis of physical mechanism of partial discharges initiation and development in the case of micro-needle type defects is described.

Uncovering Gas Insulated Substation Transient Behaviours Using the Equivalent Cable Model

“…The fault occurs between the phase conductor and the metallic enclosure when the amplitude of the generated VFO becomes greater than the Lightning Impulse Withstand Voltage of the substation [4]. Several modelling techniques applied to GIS transient behaviour that exist are based on circuit theory and electromagnetic field theory [5][6][7]. The numerical electromagnetic field method can deal with both transversal electromagnetic propagation mode (TEM) and non-TEM propagation mode [8].…”