Augmented Thevenin Model for the Harmonic Analysis of Switching Circuits

This article addresses the use of the Thevenin equivalent model in the case of switching circuits. An augmented Thevenin model is proposed, based on a well-established augmented equivalent approach for the analysis of periodically switched linear networks. It can profitably be used to provide a time-invariant equivalent description of a switching network and to investigate on the harmonics behavior at any of its ports even upon the varying of one of its internal parameters. This makes the article interesting for harmonic analysis purposes as, for instance, in the analysis and troubleshooting of electromagnetic interference or in the monitoring of a system behavior through the assessment and analysis of some of its spectral components. The model has also the advantage to be simple in its implementation. The feasibility and potentiality of the method are verified via simulations and comparisons with the results obtained by applying the augmented equivalent approach to the case of a dc–dc Buck converter.