Comprehensive Black Box EMI Model of Power Electronics Converters in Supraharmonics Frequency Range

Predicting electromagnetic interference (EMI) in the 2–150 kHz range using accurate power converter models is receiving significant attention from the electromagnetic compatibility community. However, developing these models is challenging due to the difficulty in accessing detailed information about the converter internal architecture, including parasitic elements. This complexity complicates the precise prediction of EMI at both the device and system levels. This study proposes a simplified black-box model for both single-phase and three-phase converters, tailored for complex EMI analyses. The model accounts for both differential mode (DM) and common mode (CM) equivalents, enabling effective noise mitigation during EMI design. Additionally, the modeling process incorporates an online impedance measurement technique, allowing converters to be modeled while in operation. A simple experimental approach for validating the proposed black-box model is also presented. The experimental results demonstrate that DM impedance is heavily influenced by the converter’s on/off status. The proposed black-box models have been validated with a high level of accuracy, revealing that CM impedance asymmetry in the single-phase converter is a key factor during the validation process.