Common Mode EMI Characterization Through Phase Modeling

This paper presents the advanced phase modeling of conducted common-mode (CM) EMI of wide bandgap (WBG) power switch. The state-of-the-art approaches mostly analyze CM EMI through a circuit model. While circuit simulations provide high-resolution analysis, it commonly leads to long simulation time and incomplete convergence issues arise due to its high complexity; this becomes challenging in increasingly complicated power electronics systems. In this paper, a new signal processing approach has been proposed for the SiC half-bridge module to address such a critical issue through precise phase modeling. If successful, this proposed modeling could allow a novel analysis of the phase and timing differences between CM EMI caused by different parasitic elements of WBG switches within an extensive power-electronics-enabled-power-system, hence, allowing system-level analysis of CM EMI. The proposed method has been compared with that of a conventional circuit simulation tool to validate the effectiveness. The proposed algorithm is also validated with a 300kVA medium voltage SiC MOSFET-based EMI testbed.