Small-signal modeling and analysis of the double-input buckboost converter

Multi-input dc-dc power electronic converters have been gaining popularity in applications such as renewable energy sources and electric-drive vehicles due to their reduced part count and flexibility in integration. In this paper, the small-signal model of the double-input buckboost converter is developed. The model is then used for a multiple loop feedback design. Considering a photovoltaic-battery hybrid power system, the control objectives are threefold. These include output voltage regulation, constant power demand from the PV panel, and load accommodation by the battery pack. Two feedback compensation networks are designed based on the developed small-signal model. It is also demonstrated that the two inputs of the double-input buckboost topology can be controlled independently. This offers greater flexibility for the compensator design. The results of the time domain analysis are consistent with those of the theoretical model.