METHOD FOR AUTOMATED MONITORING OF SERVICEABILITY OF MEASURING PATHS OF MULTIFUNCTIONAL ELECTRIC ENERGY METERS IN THREE-PHASE NETWORKS WITH ISOLATED NEUTRAL Russian patent published in 2025 - IPC G01R35/04 G01R31/50 

FIELD: electric power industry; measuring.

SUBSTANCE: invention relates to power engineering, specifically to equipment for measuring parameters of distribution three-phase electrical networks with isolated neutral voltage from 6 to 35 kV. Instantaneous values of current and voltage of each phase and interphase voltages are measured by means of three analogue-to-digital converters (ADC). Each ADC has three measurement channels, besides, each ADC is under potential of one of the phases. Obtained values are transmitted to the processing device and the instantaneous values of phase active powers, phase reactive powers obtained from the ADC are generated from the instantaneous values of phase currents, as well as total on phases of active, reactive and full power and values of voltage and current of zero sequence. Serviceability criterion of measuring circuits of electric energy meter is compliance with ratios: [P1 - P2] < ∆P, [P1 - P3] < ∆P, [P - P2] < ∆P, where: P = Pa + Pb + Pc is total power value, Pa, Pb, Pc are values of active powers for each of phases, P1 = Ia * Uab + Ic * Ubc, P2 = Ia * Uac + Ib * Ubc, P3 = Ib * Uab + Ic * Uac are total power determined by Aron scheme using interphase voltages and phase currents, Uab, Ubc, Uac are phase-to-phase voltages, ∆P is the permissible limit of error in determining the difference for each of the ratios.

EFFECT: providing control of serviceability of measuring circuits of multifunctional electric energy meters at the place of operation, possibility to distinguish metrological failure of any of measuring channels from external faults of the line, in particular, occurrence of single line-to-ground faults.

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