Extended Research on Small-Signal Modelling of Current-Mode Controlled Parallel-Input/Series-Output Buck-Based Converters

A more detailed state-space-based small-signal model is developed for peak current-mode controlled parallel-input/series-output buck-derived dc-dc converters operating in the continuous conduction mode. The model allows the control of each module individually; and it includes the sampling effect of the module current loop. The derived model is employed to assess the effect of mismatch between the output-filter inductors on the control-to-output voltage responses of a two-module converter. Results from the detailed cycle-by-cycle simulations are in good agreement with the predictions of the mathematical model up to half the switching frequency.