Efficient High-Frequency Isolated Buck-Boost Matrix Converters With Reduced Components and Continuous Input Current

This article develops two circuit variations of a new single-phase high-frequency transformer-isolated (HFTI) buck boost matrix converter (MC). Both MCs feature continuous input current, with one topology providing continuous output current and another reducing component count further. These MCs offer symmetric bipolar voltage gain, supporting both inverting and noninverting output voltages, as well as an output voltage with step-change frequency and rectification. The adjustable bipolar buck-boost output of the converter, step-variable frequency operation, and voltage rectification capability make it suitable for high-gain traction systems, rectification, and use in dynamic voltage restorer (DVR) applications. Key advantages include substantial component reduction, low total harmonic distortion (THD) in both input and output currents, enhanced magnetic utilization, and the ability to operate with various winding ratios without compromising the buck-boost function or its voltage range. Additionally, integrating an HFT in both topologies eliminates the need for line-frequency transformers, enabling more efficient grid integration. Both MCs also benefit from inherent commutation. The comparative evaluations confirm that the proposed MCs perform better than existing designs in terms of maximum switch voltage, switch utilization factor, efficiency, and volumetric performance. The paper presents the operating principle of the proposed MCs, followed by experiments to verify their operation and performance.