Double-Star Uncontrolled Rectifier Based On Power Electronic Transformer

The size of the traditional transformer limits the utilization of multi-pulse rectifiers in many applications. To solve this problem, this paper proposes a double-star uncontrolled rectifier based on power electronic transformer (PET). Since the volume of the transformer can be effectively reduced by increasing its operating frequency, this topology uses the PET comprised of a power electronic converter and a high frequency transformer instead of the traditional transformer. In this paper, the operating modes of the three-phase half-wave rectifiers are analyzed, and the mathematical expressions of the input current and the load voltage are derived. The results show that the proposed topology can significantly reduce the size of the isolation transformer and improve the system power density while ensuring the same input current quality. Simulation and experimental results demonstrate the effectiveness of the theoretical analysis.