A Highly Reliable Low-Cost Single-Switch Resonant DC-DC Converter with High Gain and Low Component Count

This paper presents a novel low-cost, single-switch, high-step-up resonant DC-DC converter with high reliability. The proposed converter topology comprises a low count of components and a simple structure and achieves the low ripple input current characteristic. The inductors in the resonant network participate in the resonant process rather than creating voltage spikes across the switch and likely reverse recovery problems. The circuit operates in the soft-switching condition (ZVS-ZCS conditions in the turn-off and turn-on transitions), leading to a significant reduction of the switching losses. Moreover, employing film capacitors instead of electrolytic capacitors reduces the size of the circuit and improves reliability. The operational principle and comprehensive steady-state analysis in the continuous conduction mode (CCM) are discussed in detail, alongside the design considerations of the proposed converter. The validity of the theoretical equations is investigated via experiments, achieving maximum efficiency of 97.69% for a converter designed at the input of 24.5V, the negative output of 200V, and the maximum power of 200W.