A ZVS High Step-Up DC–DC Converter for Renewable Energy Systems With Simple Gate Drive Requirements

Abstract

In this article, we propose a high step-up interleaved dc–dc converter with zero-voltage switching, which is based on the coupled-inductor technique and voltage multiplier cell. A capacitor is placed in series with the secondary windings of the coupled inductors to increase voltage gain so low-voltage-rated and <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> -resistance <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s can be employed to reduce conduction losses. By using auxiliary switches, soft switching is provided for a wide range of load variations. Due to the presence of the leakage inductor, all diodes are turned <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> with zero-current switching condition, so the reverse recovery problem is alleviated. Besides, the thermal stress of the phases and the input current ripple are low due to the interleaved structure applied. The operation principle and steady-state analysis of the presented converter are discussed. Finally, in order to verify the operation of the proposed converter, a 28 V input voltage to 460 V output voltage prototype with a rated power of 250 W is implemented and tested in the laboratory.