Modeling and analysis of the hybrid buck-boost converter with switched inductor structure

Hybrid Buck-Boost converter with switched inductor structure (HBBCSI) is a good topology for obtain the negative output voltage since it has high voltage gain when it compares to the conventional Buck-Boost converter. In this study, based on the relationship between the two inductors, the operational principles are analyzed in detail. From the timedomain waveforms of two inductor currents and using the averaging method, the averaged and small signal model of the HBBCSI operating continuous conduction mode (CCM) are derived and analyzed. It is found that, unlike the conventional Buck-Boost converter, the current through the inductor with bigger inductance of the HBBCSI will be maintain a nonzero constant value within a certain interval and this point is the key for establishing its averaged and small signal model. Finally, the PSIM simulation results are presented for confirmation.