To make clear the inrush current through feeder switches caused by the distribution transformers on the feeder
a systematic sampling method with a certain sampling interval of closing angle and opening angle is employed to form a large number of scenarios
under which
the inrush current through the feed switch is analyzed based on PSCAD/EMTDC. To the authors' knowledge from comprehensive statistics to the analytic results
it is indicated that the closing inrush current multiple of several transformers is smaller than that of a single transformer. It is concluded that the fundamental component of the inrush current through a feeder switch is generally less than ten times the summation of the rated current of the distribution transformers downstream the switch. It is also found that the probability distribution of the inrush current through a switch is roughly the same when the total capacity of its downstream distribution transformers is certain
regardless of the capacity combinations. The analysis results of the probability distribution of the inrush current through a switch with the total capacity of the downstream transformers of 3~15 MVA are given
which is helpful to determining the setting of instantaneous current protection. This work is supported by State Grid Corporation of China.