METHOD OF DOUBLE-SIDED WAVE DETERMINATION OF SINGLE-PHASE SHORT CIRCUIT LOCATION ON POWER TRANSMISSION LINE WITH BRANCHES Russian patent published in 2025 - IPC G01R31/08 

FIELD: electrical engineering.

SUBSTANCE: point of single-phase short circuit (SC) is determined by measurements of two devices installed at ends of power transmission line (PTL). Phase currents are measured in each device and linearly converted into a wave process signal. Moment of arrival of the primary wave to the device is recorded. Information on the moment of arrival of the primary wave to it is received from another device. Distance to the expected point of the single-phase short-circuit on the power transmission line is determined, which is compared with the distances to its branches. If this distance is not equal to distance to any of branches, then it is accepted as true, otherwise it is accepted as damaged one of branches, distance to which is equal to distance to assumed place of single-phase short circuit on power transmission line. According to the wave process signal, the moments of arrival of waves following the primary one are recorded, the moments of arrival of the monitored waves are selected among them, and duration of intervals between them and the moment of arrival of the primary wave to the device is estimated. Polarity of the primary wave and the polarity of the waves following it are determined. Monitored waves are those whose polarity coincides with the polarity of the primary wave. Information on durations of intervals between the moments of arrival of the monitored waves to it and the moment of arrival of the primary wave is received from the other device. Pairs of equal pairs are identified among said durations of intervals of two devices, and the interval between the moment of arrival of the monitored wave with maximum amplitude and the moment of arrival of the primary wave to the device is selected and taken as the working interval. True distance to the point of the single-phase short-circuit is the distance to the point in the damaged branch, to which the wave from the transformer in the damaged branch reaches for half the operating interval.

EFFECT: high accuracy of determining the distance to the point of single-phase short circuit (SC) on a power transmission line (PTL) with branches.

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