Estimation of radiated high frequency magnetic and electric fields in 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 frequencies of transient field's ranges from 25MHz to 40 MHz and are observed at various locations considered for measurement. The magnitudes of transient fields are compared at each location. 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.