Equipotential surfaces and electric fields for substation

摘要

This paper proposes a new theoretical – graphical digital simulator based on electromagnetic theoryprinciples, to evaluate the Corona Effect inside a substation environment, where EHV transmission linesand other energized elements get close to each other and to substation grounded structures. The CoronaEffect appears more intensively when the natural insulating medium, the air, is contaminated byatmospheric effects, vegetal or animal or mineral materials, or any dirtiness, etc., decreasing its dielectricstrength. In this case the electric field intensity at the conductor surface could be over a critical airdisruptive electric field (E_0), which is calculated with the Peek's formula and Corona Effect appears withsome contaminant effects such as a luminous halo around the conductor, radio interference, audible noiseand sulphurous gases. This new method proceeds drawing substation equipotential surfaces Vxy anddefining electric field Exy for all xy points over a substation chosen cut plane in order to determine theE_(max) value at the substation conductive surfaces. The method applies quite effectively to Corona Effectstudy at HV and EHV substations and it efficiently combines theoretical principles with practicalapplications for substation design.