3 Phase System Line to Ground fault Fault current calculation

  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. 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.
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