FIELD: electricity.
SUBSTANCE: invention is related to electric engineering, in particular to electric equipment installed at power stations and substations in systems of production, transfer and consumption of electric power, and it may be used in all electric installations using digital data processing. The value XC is determined as a constant component in electric current signals, in current and voltage for each phase and in neutral lead on permanent basis N times within T period and at each current time ti the current value of signal x(ti) is recorded and the sum Ri=x(ti)+x(ti-N/2) is calculated with the same value of electric signal, which was observes half-period N/2 ago at time ti-N/2. Then current value of the sum Ri is compared to value of the sum Ri-1, that is to say with the value observed at the previous measurement of electric signal x(ti-1) at time ti-1. Equality within the preset interval, for example, within quarter period for these sums values, i.e. absolute value of their difference Ri-Ri-1≤b, does not exceed b, where b is the preset accuracy for determination of constant component level serves as the precondition for availability of the constant component XC, which value is calculated as per the formula XC=(x(ti)+x(ti-N/2))/2, where x(ti) is current value of electric signal at time ti; x(ti-N/2) is value of the same electric signal observed half-period N/2 ago.
EFFECT: technical result consists in simplified equipment intended for identification of distortion type.
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