if the synchronizing b/w
generator and busbar not
complete and we close the
out going circuit breaker
of generator then what
happen ?

Answer Posted / milinda4p

IF the synchronization does not complete and if you close a cct breaker a severe arcing may occur and generator will trip instantaneously. Because the Generator sides voltages and bus side voltages do not match. To match the volatges following has to satisfied.
1. voltage magnitude
2. phase angle difference - 0
3. phase sequence - same
So at this condition there might be present voltage or phase angles or phase position mismatches. Say for example there exists a voltage magntude mismatch of 1 kV and when you close the cct breaker contact points have that voltage across them and this will cause severe current through contact points of breaker

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