1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: 3 Phase System Line to Ground fault Fault current calculation

  1. Nov 29, 2007 #1
    Six, 6.6kV ,3phase, alternators are connected to a common set of bus bars.
    Each has positive negative and zero sequence reactances of 0.90 ohm, 0.72 ohm, 0.30 ohms respectively . An earth fault occurs on one bus bar . Determine the value of fault current if all alternator neutrals are solidly grounded.

    HINT: Fault Current,I =3V/(Z0+Z1+Z2) for single generator when single Line to ground fault occurs.

    where, V is the Phase voltage (i.e. ( 6.6kV / 1.732 = 3.8106 kV ))

    Can anyone help me on how to solve this problem. Please.
    Last edited: Nov 29, 2007
  2. jcsd
  3. Nov 29, 2007 #2
    It's been a while, but if memory serves...
    Total current = I1 + I2 + I0
    You have the impedances. Do one at a time.
    I'll do a little book work and see if I can get back up to speed.
    Post again if you are still stumped.
    I'll try to help.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook