Parametric Average-Value Modeling of Multiple-Input Buck Converters

Average-value modeling of DC-DC converters is an indispensable tool for analysis of power electronic systems. However, analytical derivation of accurate models may be quite challenging especially when multiple modes and the circuits´ parasitics are considered. Recently, a computer-aided average-value modeling approach has been proposed in the literature, wherein the average model has a well-defined structure and is constructed with the assistance of the detailed simulation. This paper extends the parametric approach by appropriately including the multi-input source and output dynamics. The approach is based on corrected state-space average model, where the so-called duty-ratio constraint and correction matrix are expressed as nonlinear algebraic functions of the duty cycle and the switching-stage dynamic impedance. The proposed model is shown to be accurate in predicting large-signal time-domain transients and small-signal characterization.