New Modulation and Control Scheme for Phase-Modular Isolated Matrix-Type Three-Phase AC/DC Converter

A phase-modular isolated three-phase AC/DC converter topology and its modulation and control scheme is proposed. The topology, denominated as IMY-Rectifier, is based on a star connection of single-phase mains frequency to high frequency AC/AC matrix converters at the input, feeding high-frequency isolation transformers. The transformer secondary windings are connected in series to the input of a diode rectifier with LC output filter. The converter provides a controlled output voltage and sinusoidal input currents in phase with the mains voltages. A description of the converter, its operating principle and an analytical calculation of the component stresses is presented. The proposed new control of the converter ensures a constant power flow and/or constant output voltage. Furthermore, the potential of the star point of the phase modules is actively controlled so that no connection to the mains neutral is required. Simulation results verify the operation of the new control scheme. In addition to the proposed isolated AC/DC converter topology, alternative Boucherot network based topologies for high-frequency load independent constant AC current output and dual circuits are presented in this paper.