Fully Soft Switched Ultra-High Step-Up Quadratic Converter Without Reverse Recovery Issue

This paper presents a new ultra-high step-up converter with fully soft switching conditions. In the proposed converter, ultra-high voltage gain is obtained by combining the coupled inductors (CIs), voltage multiplier cell (VMC), and the quadratic structure. To provide soft switching conditions, an active clamp circuit is used to recover the leakage inductances energy as well as boost the voltage gain. As a result, the switching and capacitive losses are reduced. The reverse recovery problem of the input diodes in quadratic converters is a major challenge. Due to the presence of CIs leakage inductances, all diodes experience low reverse recovery characteristic. Since the proposed converter has a low number of utilized components and because of the mentioned benefits, high efficiency is attained. In addition, the presented structure has common ground between the input and output while input current is continuous. The experimental results are achieved utilizing a laboratory prototype developed for 48 V to 650 V at nominal output power of 200 W to validate the proposed converter theoretical analysis.