A Non-Isolated Single-Output Bipolar Buck-Boost DC-DC Converter with Reduced Components

This paper presents a new non-isolated buck-boost DC-DC converter with a single bipolar output. The proposed converter incorporates a two-switch impedance network that facilitates two-quadrant operation. This design reduces the number of required components and allows the converter to handle both forward and reverse output currents, providing both positive and negative output voltages. The converter features a coupled-inductor, and its turn ratio can be adjusted to extend the converter's step-down and step-up operating ranges, thereby enhancing the output voltage gain. Compared to existing designs, the suggested topology significantly reduces the number of switching devices and passive components while improving efficiency, volumetric performance, switching device power handling, and magnetic component utilization. Additionally, the proposed converter features a common ground point between the input and output, as well as continuous input current. The paper introduces various circuit configurations for the converter, each offering different output voltage gains. A straightforward switching method, which eliminates dead time, is also proposed. This article details the operation of the converter and verifies this design concept using a laboratory-built prototype.