Распознавание короткого замыкания при каскадном отключении повреждённой цепи в двухцепной линии электропередачи

Abstract

The article supplements the previously published analysis of the informational contribution of a cascade disconnection of a power line to the recognition of a short circuit (SC) that has occurred in it. The determination of the short circuit in one-way observation of the line increases due to the disconnection of the opposite side, but there is still a need to attract full information about the phase values, including, which is undesirable, their components of the zero sequence. The article shows that in the case of a double-circuit power transmission line, including bypass communication, cascade disconnection of the damaged circuit opens up a fundamentally new opportunity to evaluate the voltage and current on its unobservable side. The situation is very much, though not in all, reminiscent of two-way observation of a damaged circuit. The main thing is that quasi-two-sided observation, like ordinary two-way observation, can be carried out in two-wire channels of phase quantities that are freed from the components of the zero sequence. The efficiency of dividing zero - free phase currents into two components is shown: the normal one, determined in the model of an undamaged line, and the local one, operating in channels shunted on both sides. The measurement based on which the location of the fault is recognized is characterized by a priori dependence on the line coordinate. The theoretical provisions are illustrated by examples of two-chain lines, including real power transmission with branches.