Experimental investigations and calculations in 6–35 kV networks with various neutral conditions

Abstract

Resonant grounded or ungrounded neutral system produces specific overvoltages, e.g. overvoltages at single line-to-ground arcing faults. Theoretical research and field experience show that reducing overvoltage levels at arcing ground faults and decreasing the number of ground faults without increasing of ground-fault currents can be reached by connecting the neutral of the transformer to ground through a high-value resistor. Determination of real capacitance current value in 6-35 kV network is urgent and needs accurate solution.