Switching of Elevated Electromagnetic and Electrostatic Induced Currents in Multi-Circuit, Multi-Voltage HVAC Transmission Lines

This paper presents a future-proof switching procedure for the switching of increasing electrostatic (e.s.) and electromagnetic (e.m.) induced currents with a line side earthing switch. The induced currents are becoming much higher than stated by IEC-standards due to increasing line current and the use of combined (un-transposed) overhead lines. Notorious are overhead lines with different voltage levels combined at single pylons. This adapted switching procedure becomes even more important due to the increasing amount of Gas Insulated Switchgear (GIS) being introduced in the grid.