OREANDA-NEWS. January 4, 2013. 31 transformer substations, sewage disposal plants, wastewater pumping station, a school, a kindergarten and more than one and half thousand inhabitants are fed from substation # 79 “Lovtsy” of Lukhovitsky distribution zone of the Eastern branch of MOESK. To increase their power supply reliability, the power engineers of the Eastern Electric Grids performed here a reconstruction within the framework of which a substitution of the safeguard systems of the primary equipment by new microprocessing terminals has been made on outgoing 10 kV OL; the safeguard systems are produced using an electromechanical relay.

Unfortunately, relay protections on electromechanical relays have a series of drawbacks, being deprived of self-diagnostics and not making it possible to determine own working capacity, restricting a possibility of the load consumption by the consumer owing to a high returning ratio, as well as divide a network to longer segments, therethrough increasing a quantity of the disconnected subscribers. It can entail not only a breakdown of the power equipment, and as a result, an increase of number of the deenergized consumers, and subsequently will complicate a process of fault location detection.

New protection on the microprocessing terminals combines four functions of protection and automation in itself, which makes it possible to keep constantly a long-haul line under control, thanks to a possibility of its division to several short areas; on each of them the protections are installed. Should a failure occur at any area, that particular area is deenergized, rather than all the line. Accordingly, the number of deenergized subscribers is reduced.

Advantage of the microprocessing protections consists also in their information capacity. The new automation makes it possible not only to test a line constantly for the subject of its working capacity, but as well as to determine a reason for power supply disconnection, to inform a dispatcher immediately of all the failures arising and even to determine a distance to a place of failure.

By the words of Deputy Head of the relay protection service in Kolomensk service zone of the Eastern electric grids, Eduard Terent’yev, the substitution of the relay protections at SS # 79 “Lovtsy” by microprocessing ones, increases essentially the quality and operational efficiency of power engineers as to the possible failure elimination, and alongside with that the power supply reliability of consumers and socially significant facilities of Lukhovitsky district of Moscow region.