New Dual-Input Zero-Voltage Switching DC-DC Boost Converter for Low-Power Clean Energy Applications

This article introduces a new dual-input nonisolated zero-voltage switching (ZVS) dc-dc boost converter. The proposed converter hybridizes two bidirectional and unidirectional boost converters to harvest energy from a rechargeable energy storage element and a clean energy dc generator, respectively. Hence, the proposed circuit utilizes three power switches, one power diode, two inductors, and an output filtering capacitor. The ZVS of all the power switches and zero-current switching (ZCS) for the power diode are realized without any auxiliary circuit. The soft-switching performance is designed to be valid for the whole power ranges of the converter input sources and the output load. The converter power switches are switched in pulsewidth modulation manner with two individual duty ratios, allowing to regulate the converter output voltage and control the extracted power from the input unidirectional port through a simple and useful control system. Depending on the converter duty ratios, its basic operation principle is analyzed in two different operation cases. The proposed converter benefits from a simple and compact structure, minimum numbers of power switches and magnetic elements, and high efficiency. The behavior of the proposed converter is analytically investigated, and a low-power laboratory prototype is designed and fabricated to evaluate the converter performance in different operating conditions.