A single-phase high step-up common-ground direct AC–AC converter with reduced switches stress

This paper introduces a single-stage boost AC–AC converter based on a switching-cell configuration. The suggested topology is designed to achieve high voltage gain while reducing the size and weight of magnetic components, and also, minimizing overall conduction losses. By providing continuous input and output current waveforms, the converter reduces current ripple, while the experimentally measured THD values confirm the limited distortion of the input current and output voltage waveforms. The proposed design provides a duty-cycle-controlled voltage gain while preserving the phase and frequency of the input voltage at the output. This operating principle enables direct high step-up AC voltage conversion without requiring a bulky line-frequency transformer. Additionally, the simplified circuit, fewer bidirectional switches, and reduced voltage stress on semiconductor devices enhance efficiency, and implementation feasibility. A detailed theoretical analysis is presented, including operating principles, mode analysis, component design considerations, and performance evaluation. The effectiveness of the introduced converter is validated experimentally. The laboratory test is conducted at an input voltage of 20 V, a duty cycle of D = 0.7, a switching frequency of 50 kHz, an output voltage of 110 V, and an output power of 250 W. The obtained results confirm the capability of the converter to provide high voltage gain and enhanced performance, making it suitable for inductive power transfer systems, AC power conditioning applications, and low voltage AC energy interfaces.