EMI Filter Robustness in Three-Level Active Neutral-Point-Clamped Inverter

The electromagnetic interference (EMI) filter is a critical component for power electronics to conform with the EMI standards, ensuring electromagnetic compatibility and a safe operating environment. Yet, its attenuation capability can shift during the long-term operating period due to the passive components’ degradation. A poorly designed EMI filter may fail to meet the standards’ specifications and affect the robustness, leading to the converter level fault and even failure. This article proposes a robustness assessment procedure of an EMI filter for a three-level active neutral-point-clamped (3L-ANPC) inverter. The mission profile is used to emulate the operating environment. The nonlinear degradations of film capacitors and nanocrystalline core chokes are modeled. Furthermore, the Monte-Carlo-based robustness assessment procedure is presented. It considers the uncertainties of model parameters and uses the filter attenuation capability as the failure criteria. Finally, an EMI filter for a 15-kW 3L-ANPC inverter is used as the demonstration and experimental verification of the evaluation procedure. The B10 lifetime of the EMI filter is obtained, which serves as a first step of the inverter-system-level EMI robustness evaluation and feedback for the robustness-oriented EMI filter design.