METHOD FOR DETECTING INTERTURN SHORT CIRCUITS IN THE WINDINGS OF THREE-PHASE CONSUMER TRANSFORMERS Russian patent published in 2023 - IPC G01R31/62 G01R31/72 H02H7/04 H01F27/30 

FIELD: electrical engineering.

SUBSTANCE: invention can be used to detect interturn short circuits in the windings of three-phase consumer transformers during operation. The method for detecting turn-to-turn short circuits in the windings of three-phase consumer transformers consists in measuring the phase currents of the transformer in idle mode using measuring current transformers. The first measurement is made before starting operation on a known-good transformer. The signals coming to the measuring current transformers from the measuring current transformers are processed, and the result is stored. During the operation of a three-phase transformer, during a scheduled inspection, measurements of the phase currents of the transformer are repeated with the load disconnected and the signals are re-processed. The processing of signals coming from measuring current transformers consists in the fact that after removing the signals from the ammeters during the first measurement, the direction of the current vector of one of the phases is selected, the angles between the vectors of the phase currents are determined, and the value of the negative sequence current vector for the selected phase is calculated. The result obtained is compared with the result of the first measurement, and the presence of interturn short circuits is judged by the absolute value of the vector difference between the calculated negative sequence current vectors, which, in the presence of an interturn short circuit, will be greater than zero.

EFFECT: increasing the sensitivity to the presence of short circuits in the windings of a three-phase power transformer by taking into account negative sequence currents.

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