Uncertainty models for switch-mode DC-DC converters

Uncertainty models for the three basic switch-mode converters, buck, boost, and buck-boost, are given in this paper. The resulting models are represented by linear fractional transformations (LFTs) with structured dynamic uncertainties. Uncertainties are assumed for the load resistance R=R_o(1+δ_R), inductance L=L_o (1+δ_L), and capacitance C=C_o(1+δ _C), The interest in these models is clearly motivated by the need to have models for switch-mode DC-DC converters that are compatible with robust control design, which require a model structure consisting of a nominal model, and a norm-bounded modeling uncertainty. Therefore, a robust controller design under parameter uncertainties can be obtained instead of the deterministic approach widely used