Ultra-Light Load Performance Enhancement of A 1 MVA SiC Medium Voltage Three Phase Rectifier

This paper provides a comprehensive study to adapt dual-active-bridge (DAB) power-factor correction (PFC) rectifier design to the medium voltage (MV) high power (HP) variable frequency drive (VFD) systems. First, the novel silicon carbide (SiC) MV three-phase (3 Ph) PFC rectifier is proposed. Its topology, key SiC module and control scheme are presented. Second, control enhancement to keep the grid current total harmonic distortion (THD) at a minimum at ultra-light load is discussed. The proposed topology has a novel circuitry mechanism to improve the THD at the ultra-light load condition. Analysis and simulations are carried out to verify the proposal.