Symmetric Dual-Switch Converter

High step-up dc/dc converters are widely used in many industrial applications, especially in green energy power generation and uninterruptible power systems. The circuit configuration of a dual-switch high step-up dc/dc converter is very simple and the converter can achieve a high step-up voltage gain by operating in parallel charge and series discharge. However, this converter has a strict requirement of the parameter's consistency or it will lead to the high voltage stress of switches due to parasitic capacitance and inductor's resonance. Although passive lossless clamp circuit can be adopted to realize the voltage balance of switches in steady state, unbalance voltage still exists in dynamic state owing to an unsymmetrical structure. Therefore, this article proposed a dual-switch converter with symmetric topology, which can realize the voltage balance of switches and capacitors in both steady and dynamic states. According to the proposed converter, a prototype rated at 200 W has been established in the lab and the experimental results verify the accuracy of the analysis.