Design and analysis of quasi-resonant high-gain impedance source DC–DC converter for DC microgrid

Abstract

ABSTRACT This paper presents a quasi-resonant, isolated, high-gain, Y-source, DC/DC converter for a DC microgrid. Here, quasi-resonance is obtained by the LC tank during the shoot through period, resulting in natural commutation at the turn-off instant of the MOSFETs. The LC tank is formed by an additional parallel capacitor and transformer leakage inductance. The high voltage gain is obtained by including an isolation transformer with lower turns ratio, coupled inductor and voltage doubler. Here, frequency is modulated to regulate the output voltage with ON period constant. This converter’s zero current switching feature allows it to operate at a higher switching frequency and thus enhances the power density and efficiency. This converter’s continuous input current feature is an added advantage. The proposed converter inherits all the benefits of traditional impedance source converters. Finally, a 250 W hardware prototype is developed, and its performance is tested in the laboratory.