High frequency magnetic and electric field measurements and simulation of a 245kV GIS

The transient high frequency electric and magnetic fields are generated in Gas insulated substations(GIS) systems during switching operations by both radiation and conduction mechanisms. In this paper the radiated transient electric and magnetic fields are measured by using high frequency field sensors at important locations in the 245kV GIS were presented. The measurements are carried out at three important locations including at bus link, cable termination and C.T position respectively. The results of measured values are compared with the calculated values. The results shows that transient electric & magnetic field values are correlate with the measured values at bus link, near current transformer(CT)and at cable termination , the calculated values are slightly deviated from the measured values when moves along with XLPE cable. This may be due to a fast attenuation rate of electromagnetic fields with distance away from the DS3. These results are very useful in order to prepare some precautionary protection measure to avoid malfunctioning of secondary equipment and metering equipment in GIS systems.