A Novel High-Gain Nonisolated Quasi <i>Z</i> -Source DC–DC Converter With Symmetric Bipolar Outputs

This paper proposes a single-switch, high-voltage-gain quasi Z-source (qZS) DC-DC converter that employs voltage multiplier techniques to boost the voltage gain and deliver a bipolar output. The proposed topology ensures a continuous input current (CIC) and provides a common ground (CG) between the input and output, while limiting the semiconductor voltage stress to half of the total output voltage. A 256W prototype with ± 360V output demonstrates a voltage gain of 11.5 and an efficiency of 93.4%. Theoretical analysis, experimental verification, and a comprehensive comparison study, with state-of-the-art converters substantiate the performance advantages of the proposed design. With its high voltage gain, common grounding, CIC, and single-switch self-balancing configuration, the converter is ideally suited as an interface for renewable energy sources, such as photovoltaic systems, and bipolar DC microgrids.