The study of inrush current phenomenon using operational matrices

The paper presents a new methodology for calculating magnetizing inrush cur rents. Similarly to the seminal work of Rajakovic and Semlyen, all the calc ulations are conducted in the Frequency domain, hence, circumventing the ma ny problems encountered when time domain simulations are used to solve this problem. Unlike the work of Rajakovic and Semlgen [I], where a pre-determi ned sequence of steady-state "imaged" are obtained for a sufficiently long number of cycles to capture the complete picture of the inrush phenomenon, our method produces the full solution, with no loss of fidelity, of the ove rall inrush phenomenon. The solution is achieved by resorting to operationa l matrices and it is fully equivalent to that produced by time domain simul ations but carried out entirely in the frequency domain. In principle, any orthogonal series expansion could be used with this method but in this pape r Hartley series have been selected, The usefulness of the methodology is i llustrated with simple but practical circuits, Comparisons against time dom ain simulations are given.