Question

A 280-V, 3Ø AC power system, Y-connected three-phase generator connected through a three-phase transmission line to a A-connected load. The transmission line has an impedance of (0.06+j0.12) S2/phase, and the load has an impedance of (12+j9) 92 per phase. Determine the; (a) line current (I) at the load (b) line and phase voltage of the load (c) active power, reactive and apparent power (d) power factor and specify whether it is lagging or leading ya Jona

I have seen similar examples of this question. However, for both 208V and 280V AC power system, the line-to-line voltage seems to be the same which 120V and that does not make sense. Can you please justify that in the solution?

Answer 1

O mo A RT see RL RL agovim t вк, с Rp R, 0.06+j12r LI Árpuns For star comeuton R 12tjan V • 3 x V phare line I line Iphane for delta conceton Vphane V dine I line 3 I * J3 I phai Here = Qov. V supply-line - rims - Alphare) 280 kepunges 91 oze ked ** ART

28ov (nas) applies! acron load side also parallely cowweeetes Vac = Vab=&bc=2801 as they are SON a) Line current 3 Iphone = 280 V Vphare B/phai = 12+jq > Iphai 280 12+19 14.93-11.2j 2 -18.66 (-36.86 I line = 25.86-19.399 = 32.33 -36.8 6. Z! 280v b) a = &phare (load) II Della Commichel : Thai =Y=240 line c) Ploot - I remi line and (Active power, • S3 X280* 32-33 cos (-36.56) Керу CT

SI Loap.US P. load(active 12.546W SJON load 13 Velone I line wind : 13 x 280 x 32:33 foro (-36.86 5 – 9.405kW 1 Apparent power : Pt ja 15678.99 <-36.86 w 2 Povsor tabor cosd tort36.86) -0.800 -21 -O! As of is angle luturo-ache & reactive rower also ayle lituo volbze and merret 0 --36-86 Current lags voltage by 36.86 Lagging load 07 67 +7 87