Ae. Emanuel et al., ON THE DEFINITION OF POWER-FACTOR AND APPARENT POWER IN UNBALANCED POLYPHASE CIRCUITS WITH SINUSOIDAL VOLTAGE AND CURRENTS, IEEE transactions on power delivery, 8(3), 1993, pp. 841-852
This paper advocates much needed definitions for the apparent power S
and for the power factor PF, in unbalanced polyphase circuits with sin
usoidal waveforms. It is proved that the definition S' = (V(a)2 + V(b)
2 + V(c)2)(I(a)2 + I(b)2 + I(c)2) has a definite physical meaning, len
ding itself to a convenient resolution in positive, negative and zero
sequence, nonactive and active powers. It is suggested to represent th
e power factor with the help of the ratio P+/S, where P+ is the positi
ve sequence active power.