Experimental investigations and calculations in 6–35 kV networks with various neutral conditions英文翻译.pdf

Experimental Investigations and Calculations in 6-35 kV Networks with Various Neutral Conditions A. Shirkovets, A. Vasilyeva, A. Telegin LLC BOLID, Novosibirsk, Russia ABSTRACT: Resonant grounded or ungrounded tion of capacitive currents at fault locations, providing neutral system produces specific overvoltages, e.g. conditions for self-quenching of arc and, in some cases, overvoltages at single line-to-ground arcing faults. overvoltage limitation. However, there remains a danger Theoretical research and field experience show that of high overvoltage ratios at arcing ground faults in reducing overvoltage levels at arcing ground faults conjunction with open-phase conditions at nonsimulta- and decreasing the number of ground faults without neous operation or failed switch phases, or with improp- increasing of ground-fault currents can be reached erly adjusted ground-fault neutralizers. In some cases, by connecting the neutral of the transformer to the used automatic tuning of ground fault neutralizer, ground through a high-value resistor. Determination because of inertial operation or permissible variation of of real capacitance current value in 6-35 kV network controlled inductive current, can't eliminate high over- is urgent and needs accurate solution. voltage ratios induced at arcing ground faults [3], [