Three-Phase Multilevel PFC Rectifier Based on Multistate Switching Cells

This paper presents a three-phase multilevel power factor correction (PFC) rectifier employing multistate switching cells. A generalized converter structure is presented based on the connection of switching networks of Vienna-type rectifier topologies through multiinterphase transformers (MIPTs). The resulting rectifier presents the intrinsic benefits to the employed building blocks and the ones added by a modular construction that enables the reduction of passive components and overall losses. The operation of the PFC rectifier is described, including appropriate modulation and control strategies. Design guidelines for the magnetic components are derived for the MIPTs, boost inductors, and power semiconductor devices. Finally, a lab prototype is used to present experimental results. This prototype is rated at 7.5 kW and uses a modular structure to assemble a four legs per phase rectifier. Efficiency above 98% from 40% load and IEC61000-3-2 requirements are observed.