Unified Topological Modeling Method of Switching DC-DC Converters in Duty-Ratio Programnned Mode

A unified continuous small-signal modeling method of switching dc-dc converters operating in duty-ratio programmed mode presented. The method can be considered a new implementation of the widely known state-space averaging approach. Its principal advan tage is a reduction of the order of the matrices to be inverted resulting in a significant simplification of the modeling procedure, especially for more complex converter configurations. The method leads to the uni- fled expressions for the elements of two useful forms of circuit model, namely, Y-parameter model and ladder LC filter-form model. To demonstrate the usefulness of the proposed modeling technique the dynamic model of the Cuk converter with damping network is derived.