T05.3 - Comprehensive Electromagnetic Interference Analysis of Neutral-Point-Less (NPL) Multilevel Inverter with Active Common-Mode Voltage Cancellation

This paper investigates a neutral-point-less (NPL) multilevel inverter (MLI), H-type inverter, and its active common-mode voltage (CMV) cancellation technique to achieve a high-level of CM EMI noise reduction in comparison with that of the conventional topologies. The proposed H-type inverter topology has no neutral connection with a single dc-link capacitor and generates two equal and opposite CMVs. These features enable a significant CM EMI noise. These are validated by simulation as well as the experimental setup where the CM EMI noise magnitude is independent of the various dc-link voltages, switching frequencies, and modulation methods due to the active CMV cancellation.