Design and Implementation of a Soft-Switching Quadratic High-Gain Converter for Sustainable Energy Applications

In this article, a novel soft-switching quadratic high-gain boost converter is proposed for sustainable energy applications such as photovoltaic (PV) systems. Switched capacitor and coupled-inductor techniques are merged to obtain high voltage gain with an appropriate duty cycle. In using a shared clamp capacitor for the switches, low
$r_{\text {ds,on}}$
switches can be used for active switching devices, and the leakage energy is recycled to the output. In addition, the zero voltage switching (ZVS) condition of all switches and zero current switching (ZCS) of the diodes contribute to lower switching losses and alleviate the reverse recovery problem of the diodes. More importantly, no auxiliary magnetic components are used. The operation principles and steady-state analysis under continuous conduction mode (CCM) are described in detail. A comparison with relevant converters is presented to verify the superiority of the proposed converter. A small-signal analysis and closed-loop control are presented, demonstrating the dynamic response of the proposed converter. Finally, a 380 W experimental prototype is designed to verify the theoretical analysis. The maximum and full load efficiencies in the experiment are 95.3% and 93.6%, respectively.