**No/VOL: **08/2019 Page no. 81

**Authors:**
Mykhailo Artemenko , Larysa Batrak , Sergii Polishchuk :

**Title: ** New definition formulas for apparent power and active current
of three-phase power system

**Abstract: ** A new definition formula for apparent power of the three-phase system is justificated. It is the average geometric value of the currents
power losses and short circuit power of the voltage source loaded by transmission line resistances. The Buchholzs apparent power formula follows
from this definition as a special case if both zero sequence components of currents and voltages are nil. Under unbalanced voltage the meaning of
apparent power in accordance with proposed formula may exceed Buchholzs one more than on 10%. The generalized definition formula for
introduced by Professor Fryze concept of power systems active current is grounded. It is part of the short-circuit current that is equal to ratio
between load power and short-circuit power of the voltage source. In such way specified active current provides up to 15% power losses gain in the
transmission line compared to the original Fryzes definition in the presence of voltage zero-sequence component.

**Key words: ** active current, apparent power, active filter, zero sequence component.