3 phase, star connected system

Discussion in 'Homework Help' started by Michael V, Nov 15, 2012.

  1. Michael V

    Thread Starter New Member

    Nov 15, 2012
    1. Statement

    A star connected load of 3300 kVA at 18 kV and a power factor of 0,8 lagging is supplied by a three-phase transmission line having a resistance of 4Ω per phase and an inductive reactance of 7Ω per phase.

    a. the sending-end voltage
    b. the percentage regulation
    c. the efficiency of the line

    2. Attempted answer

    For (a), first i took the resistance and reactance to get impedance:
    Zphase = 4 + j7 = 8,062 |60,26° Ω

    then i use the rating: S = I × V (not sure if i should use VLine or Vphase)

    then to find voltage drop: E = I × Z (which current do i use?)

    I've attached my attempt.