Theoretical and experimental investigation of the fast- and slow-scale instabilities of a DC-DC converter

We use an exact formulation based on nonlinear maps to investigate both the fast-scale and slow-scale instabilities of a voltage-mode buck converter o perating in the continuous conduction mode and its interaction with a filte r. Comparing the results of the exact model with those of the averaged mode l shows the shortcomings of the latter in predicting fast-scale instabiliti es, We show the impact of parasitics on the onset of chaos using a high-fre quency model. The experimentally validated theoretical results of this pape r provide an improved understanding of the dynamics of the converter beyond the linear regime and this may lead to less conservative control design an d newer applications.