Transient processes at single phase-to-ground faults in combined grounded networks

摘要: This paper deals with the combined method of neutral grounding when a high-value resistor is continuously connected to in parallel Petersen coil. Monitoring processes at single phase-to-ground faults was organized 6 kV network large-scale iron and steel plant. Within investigation, more than 200 oscillograms voltages were analyzed. Based on recorded oscillograms, comparison between ground resonant grounded (grounding through coil) done. Numerical values dangerous for insulation transient processes, frequency distributions overvoltage levels, arc durations obtained by methods statistical processing. Field experience networks shows that operated resistors reduce amount emergency outages caused 4–6 times decrease undersupply energy customers; maximum duration, breakdowns multiplace also decrease.