The development of new analysis and measurement of various line-to-ground phenomena in transmission and distibution systems

In general, it has been impossible to accurately know the phase-to-ground admittances of live three-phase three-line network systems, from calculation or measurement. For this reason we could not analyze accurately the line-to-ground fault phenomena, especially at high impedance grounding, in live network systems. This paper proposes a new technique for analyzing various line-to-ground phenomena and accurate measurement methods of phase-to-ground admittances in transmission and distribution systems. These new analyses and measurement methods are very useful for investigating ground fault phenomena in unbalanced three-phase networks and for planning ground fault protection measures and for developing automatic apparatus for metering and controlling transmission and distribution systems.