The peak values of inrush according to the duration for
different magnitudes of voltage sag is shown in Fig. 2. It is
obtained that the inrush current peaks to its highest value at
the sag duration of 0.11 ms for the sag magnitudes (m) both
30% and 50%. The inrush currents at fault clearing instant
appear if the voltage polarization changes opposite to sag
starting point polarization. Because the sag recovery point
does not coincide with the sag starting point and can not
keep the steady state condition to continue.