A New Transformerless Buck–Boost Converter With Positive Output Voltage

Abstract

A new transformerless buck-boost converter with simple structure is proposed in this study. Compared with the traditional buck-boost converter, the proposed buck-boost converter's voltage gain is squared times of the former's and its output voltage polarity is positive. These advantages enable it to work in a wider range of positive output. The two power switches of the proposed buck-boost converter operate synchronously. In the continuous conduction mode (CCM), two inductors are magnetized and two capacitors are discharged during the switch-on period, while two inductors are demagnetized and two capacitors are charged during the switch-off period. The operating principles, the steady-state analyses, and the small-signal model for the proposed buck-boost converter operating in CCM are presented in detail. The power electronics simulator (PSIM) and the circuit experiments are provided to validate the effectiveness of the proposed buck-boost converter.