Control Strategy of Three-phase Single-stage Matrix-type Isolated AC-DC Converters with Three-order Resonant Tank

This article proposes a control strategy for the three-phase single-stage matrix-type LCL resonant AC-DC converter. A five-level voltage is generated through the matrix converter, and the derivation process is simplified using the fundamental harmonic analysis (FHA) method. The critical soft-switching conditions are modified to achieve fully zero-voltage switching (ZVS) for all switches. Analytical expressions for the input phase current and control variables are derived based on the resonant current. A dual-loop voltage and current control scheme is adopted to regulate the output voltage and input current. A dead-time compensation method is implemented to achieve smooth current commutation. Furthermore, the transformer turns ratio and resonant inductance optimized for minimal losses are derived through loss analysis, enabling further enhancement of the converter efficiency. A 1.6kW experimental prototype was constructed to validate the proposed control strategy, and the results demonstrate its advantages of high efficiency and high input power quality.