High Step-Up “Catapult” DC-DC Converter

In this paper, a novel full-bridge high step-up resonant non-isolated dc-dc converter is presented. The proposed topology is a unique method for obtaining very high voltage gains as it utilizes resonance as a key player in boosting the voltage gain. Compared with the converters of the same ilk, the number of components is modest while providing excellent output power level and step-up gain. The name “Catapult” converter is chosen because the function of capacitors in the middle stage of the converter which exploits resonance to boost the output voltage resembles to that of a catapult. All switching devices enjoy zero voltage switching and the diodes enjoy zero current turn off. The converter can operate both by frequency modulation and phase shift, above the resonance frequency. Modes of operation of the converter are described and their corresponding equations are derived. Simulations are carried out in Cadence Orcad to verify the validity of the proposed converter.