Common-Mode EMI Examination of Three-phase Voltage-Source and Current-Source Converters Systems using WBG Devices

Three-phase voltage-source converters (VSCs) and current-source converters (CSCs) have multiple dualities. This paper specifically focuses on examining the conducted common-mode (CM) EMI of VSCs and CSCs when wide bandgap (WBG) devices are used. First, the CM EMI signature of the two converters with both rectifier and inverter stages are examined. The benefits of CSC over VSC in terms of lower CM EMI are identified. The impact of adding CM chokes at different locations and the use of an LCL filter for the VSC are examined. In addition, the CM EMI associated with having only the rectifier stage or the inverter stage for each of the two types of converters are examined. Finally, a promising CM EMI suppression scheme is examined for the CSC consisting of both the rectifier and the inverter stages that requires few EMI filtering components .