A time domain simulation in a program such as ATP or EMTP should be performed. Data such as core nonlinear characteristics are needed, inrush current value depends on the instant the breaker closes.
Comment: I concur with the previous posting with the following addition: The transformer iron magnetization status on B-H curve is also a factor to be considered. If B=0, H=0 the transformer inrush will be a minimum. If B=max and H=max, the transformer inrush will be maximum for the maximum amplitude of the input voltage.
Thanks a lot guys, you help me a lot although I have to admit that I am quite confused now. I downloaded the program NetDraw free and in the help file it is written that if we enter data about iron losses and no-load current the program calculates the in-rush current. There is no sign entering data about residual flux which is one of the most important parameters for studying this phenomena.
Do you have any clues about that?
zelvica
p.s. The theory is well known to me but I cannot put in the parameters about no-load current and iron losses!
Without the source code for the program or at least the author's expanation of the theory used, it is difficult to evaluate the inrush calculation. This may be a case where you get what you pay for. ;-)
