An Isolated Current Source High Step-Up DC-DC Converter with High Conversion Ratio Output Based on a Voltage Doubler Rectifier

This paper presents an isolated current source high step-up DC-DC converter with a high conversion ratio output based on a voltage doubler rectifier. The primary function of the proposed converter is to reduce the input current ripple, turn ratio of the high-frequency transformer by utilizing current-fed and a voltage doubler rectifier, thereby converting low-input-source voltage direct current (DC) from a renewable energy source (such as a PV module) into high voltage DC using an high-frequency transformer (HFT) and the voltage doubler rectifier. The power switching devices M<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> and M<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> along with fast recovery diodes, operate under zero-current switching (ZCS) conditions. The leakage inductance of the high-frequency transformer (HFT) contributes to the soft-switching operation. A prototype of a 212 W high step-up DC-DC converter was designed, developed, and tested to assess the performance of the proposed approach. The converter was operated at a constant switching frequency of 343 kHz, with an input voltage of 12 V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DC</inf> and an output voltage of 370 V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DC</inf>. The isolated current-source high step-up DC-DC converter, designed with a voltage doubler rectifier for a high conversion ratio output, achieved a measured efficiency of around 96%.