Conducted EMI Performance of Active Neutral Point Clamped Phase Leg for Dual Active Bridge Converter based DC system

Neutral Point Clamped (NPC) converter configuration is suitable for operation at Medium Voltage DC (MVDC) level as it allows the use of a higher DC bus voltage than the blocking capability of individual switching devices. The Active NPC (ANPC) configuration offers more flexibility than NPC in terms of control and power loss distribution. NPC/ANPC phase leg aspires to be an ideal candidate for the MVDC side of a Dual Active Bridge (DAB) converter which is used in a wide range of applications requiring bidirectional power flow, voltage matching and soft-switching. Operation under Zero Voltage Switching (ZVS) and the conducted Electromagnetic Interference (EMI) performance of the ANPC converter phase leg is being analyzed in this paper. Based on the analysis, a Printed Circuit Board (PCB) bus-bar has been designed to suppress the high frequency conducted EMI of the system. Minimization of parasitic capacitance from drain to heat sink has also been discussed.