基于Buck-Boost交流斩波器的高频链分裂相电压源微逆变器以实现高效率和低电压应力

This article proposes a novel single-stage high-frequency-link split-phase microinverter that utilizes dual buck–boost ac choppers to form a secondary-side cycloconverter. This design achieves high voltage gain and a wide voltage regulation range, allowing for a reduced turns ratio in the high-frequency transformer (HFT). Consequently, voltage stress on the secondary-side switches is minimized, and associated losses in both the switches and HFT are reduced. An advanced modulation strategy is developed to enable soft-switching for all switches while effectively suppressing voltage spikes, without the need for additional clamping circuits. The microinverter supports split-phase output while maintaining voltage-source-inverter characteristics, making it suitable for both grid-connected and islanded operations. An accompanying control strategy ensures robust performance across both modes. Experimental results validate the effectiveness of the proposed topology, with a 600-W/50-Hz prototype achieving a peak efficiency of 97.12%.