An Interleaved ZVS High Step-Up Converter for Renewable Energy Systems Applications

Abstract

A novel zero voltage switching (ZVS) interleaved high step-up converter for renewable energy systems is proposed in this article. By applying a switched capacitor mixed with coupled inductor and built-in transformer, the proposed converter achieves high voltage gain and minimized voltage stress across power switches. Both of the voltage gain and the voltage stress can be adjusted by the turns ratio of the coupled inductor and built-in transformer, which gives an extra degree of freedom for the converter design. Hence, operating at high duty cycles is avoided and low voltage rated semiconductors can be adopted, which reduce conduction losses and improve the circuit performance. Furthermore, an active clamp scheme is utilized to guarantee ZVS turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> for the power <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MOSFET</small> s and the leakage inductances of the magnetic means help to provide zero current switching of the diodes. In such a case, switching losses are minimized and the reverse current recovery is alleviated. Accordingly, the proposed converter with reduced counterparts is a suitable candidate for high step-up and high power applications. Finally, a 600-W prototype with 24 to 480 V voltage conversion is built to demonstrate the performance of the proposed converter.