Design of High Frequency Resonant Converter for Wide Input Voltage Range using a Switchable Capacitance Technique /

Abstract

Due to the increase in demand for clean energy, the role of efficient power electronic converters has increased. Conventional DC-DC converter has a drawback of higher switching losses which results in a bulky heat sink. The resonant DC-DC converters are more efficient due to less power stress and zero voltage and current switching. In this research work, a 3kW LLC resonant DC-DC converter using silicon MOSFET devices was proposed. The proposed LLC resonant converter consists of three main parts including a full bridge inverter, LLC resonant tank, and high-frequency transformer. Zero voltage switching (ZVS) is achieved at a wide input range of 200V to 400V which is accommodated with a change in frequency of the LLC resonant converter. In this research work, the detailed design of LLC resonant converter with a switching capacitor technique is implemented. The switchable capacitance technique was used due to which converter operates near the resonant frequency and achieves higher efficiency. The desired voltage can be achieved at lower operating frequency as compared to simple resonant converter. The characteristics of the proposed converter circuit is analyzed and verified based on the simulation and experiment results