Three-Phase AC–AC Converter Topology Based on Partial Resonant Link and Its Soft-Switching Control Strategy

This paper proposes a novel three-phase AC–AC converter topology based on a partially resonant high-frequency link, aiming to address issues such as low efficiency, large size, and poor reliability of electrolytic capacitors in conventional converters. The proposed topology utilizes a small inductor and capacitor to form a high-frequency resonant link, enabling zero-voltage switching (ZVS) through precise control of charging and discharging cycles, thereby reducing switching losses and improving efficiency. The converter operation is divided into four modes, and a control strategy is developed based on output voltage error correction, which regulates the link peak current to synthesize high-quality three-phase output voltages. Simulation results confirm the effectiveness of the proposed topology and control method, showing stable output voltage waveforms and clearly defined current transfer behavior. The proposed converter demonstrates excellent voltage regulation capability, high power density, and significant application potential in motor drives and renewable energy grid integration.