Protection of Section Parts from Overvoltage

Abstract

World practice of operating electric networks shows that reclosers are used to partition them, as a rule. National regulatory documents governing the use of reclosers do not yet exist, which raises questions related to their operation. One such issue is surge protection for the recloser. Realization of protection of insulation of reclosers from the effects of atmospheric overvoltages can be performed on the basis of arrester. The installation of an arrester is necessary at all phases of the recloser as close as possible to its conclusions, which will limit overvoltages to the required level. Installing an arrester will reliably protect all recloser equipment from overvoltage. In this case, the arrester selection can be made according to the remaining voltage, taking into account the insulation coordination interval (at least 25%), to the test voltage of the equipment according to GOST 1516.3-96 and to check the throughput at the rated lightning currents. The analysis allows us to conclude that the values of the grounding resistance of the supports of overhead lines 6 - 35 kV, necessary to ensure the electrical strength of the linear insulation, lie in the following limits: for a lightning current of 20 kA - 10 -17 Ohms; for a lightning current of 30 kA - 6 - 11 Ohms