A PCCM ZVZCS Modulation Scheme for Full-Bridge-Boost Converter With Wide Input and Output Voltage Ranges

The full-bridge-boost (FB-Boost) converter is a popular candidate for applications with wide ranges of input and output voltages and galvanic isolation. However, previous modulation schemes for the FB-Boost converter cannot achieve zero-voltage-switching (ZVS) and/or zero-current-switching (ZCS) of all the switches, which limits the improvement of the efficiency and limits the increase of the switching frequency for higher power density. In this article, a pseudo-continuous conduction mode (PCCM) ZVZCS modulation scheme is proposed for the FB-Boost converter. With the proposed scheme, the ZVS and/or ZCS of all switches can be achieved over the whole operating range. In addition, the RMS of the inductor current is minimized to optimize the efficiency. Moreover, in the proposed PCCM ZVZCS modulation scheme, the switching frequency is constant and modulation mode transitions do not exist within entire operating range. A 1000W FB-Boost prototype with input voltage range of 100–200V and output voltage range of 200–400V is built for experimental verification.