A wide load range ZVS high voltage gain hybrid DC-DC boost converter based on diode-capacitor voltage multiplier circuit

Abstract

In this paper, a single-switch hybrid high voltage gain boost converter topology employing zero-voltage switching (ZVS) feature is proposed. The proposed converter can achieve high voltage gain with soft switching operation over a wide range of load. The topology is a combination of the Cockcroft-Walton diode-capacitor voltage multiplier and a conventional boost converter, which results in a hybrid DC-DC converter. The diode-capacitor ladder enables the converter to achieve high voltage gain without a transformer or coupled inductor. Because of its transformerless design, single switch with lower duty cycle requirement, and ZVS feature, the efficiency of the converter is improved significantly. Moreover, due to the input inductor, it is able to provide lower input current ripple and variable fractional voltage gain, which is a key requirement for maximum power point tracking (MPPT) in photovoltaic application. A 480-W hardware prototype with 48-V input voltage and 450-V output voltage is developed, and experimental results are presented to validate the efficacy of the proposed converter. The total achievable efficiency is above 95.4%, in the full load range (80-480 W).