Automatic synthesis of large signal models for power electronic circuits

The computer simulation of large signal transients in switching power electronic converters (SPEC) has not found a satisfactory solution yet. By means of popular software tools such as SPICE, the analysis in the time domain of nonlinear feedback systems is time consuming and often impractical; the recourse to mathematical symbolic descriptions, according to a copious literature, generally implies heavy preparation phases to express in matricial terms the circuit topological characteristics. Instead, small signal modeling, and dynamic responses forecast of SPECs has already found computer aids easy and fast to apply. Just such an automatic small signal analysis tool, Fredomsim, has been used, as described in the paper, to make the large signal dynamic simulation more affordable and convenient. In fact, it directly provides small signal state space matrices, and from these, the matrices required in the overall nonlinear description formulae are automatically derived. The new method is illustrated by an example.