The simple formula ( I = V/Z ) is only the starting point. Real systems add complexity:
# "F" factor calculation f_factor = (1.732 * length_ft * terminal_fault) / (conductor_constant * self.voltage) formula for short circuit current
In reality, synchronous generators have different impedances over time: ( Z" ) (sub-transient – first cycles), ( Z' ) (transient – up to 0.5 sec), and ( Z ) (synchronous – steady state). For protective device coordination, you must use the for the first few cycles. The simple formula ( I = V/Z ) is only the starting point