The new formula for apparent power and power losses of three-phase four-wire system

The new formula of the apparent power, which takes into account the power losses of the neutral conductor, has been compared with standardized one and conditions of their equivalency were found. A new physical sense of apparent power was established, it is a geometric mean value of power losses and reverse short-circuit power of supply system. The energy saving advantages of new control strategy of shunt active filter based on new determining of apparent power were shown. Analytical condition for the energy feasibility of a shunt active filter to increase the efficiency of the power system has been derived.