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Electric Generator

If all the se...

Question

If all the sequence voltages at the fault point in a power system are equal, then the fault is a

A

three-phase fault

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B

line to ground fault

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C

line to line fault

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D

double line to ground fault

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Solution

The correct option is D double line to ground fault
(d)

For double line to ground fault (LLG fault),

$V_{a 1} = V_{a 2} = V_{a 0} = \frac{V_{a}}{3}$ [if b and c phases are involved in fault]

$I_{a 1} + I_{a 2} + I_{a 0} = I_{a} = 0$

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