Improvement of adaptive single-phase automatic reclosing in extra-high voltage lines

The article deals with the issue of improving the adaptive single-phase automatic reclosing in extra-high voltage lines. The adaptive single-phase automatic reclosing devices developed in our country and abroad reduce the probability of switching on a phase at the final stage of the single-phase automatic reclosing to an unresolved single-phase short circuit or a re-arising arc, but do not completely exclude such a situation. A method is proposed in which, by preliminary calculations of the currents of the emergency phase, two zones adjacent to the systems are determined on the line, and a short-term one-sided switching on/off the emergency phase is carried out from the side of system 1, if a short or arc fault is detected in the second zone adjacent to system 2, and accordingly one-sided closing of the emergency phase from system 2, if a fault is detected in zone 1 adjacent to system 1. The proposed method for improving the adaptive single-phase automatic reclosing makes it possible to reliably identify a single-phase short or arc fault in 500 and 750 kV extra-high voltage lines with their length in the range 300 - 600 km. An example of calculating the zone boundary on a 500 kV line 500 km long is given, the necessary settings for reliable damage identification are determined.