Characterization and Modeling of Single-Phase Common-Mode Chokes via Finite-Element Analysis

The common-mode (CM) choke is critical integral part of an electromagnetic interference (EMI) filter. An accurate electrical model of the CM choke is crucial to simulate and evaluate the EMI filter performance with confidence. Numerical simulation has emerged as a feasible solution to realize the above-mentioned objectives without the presence of physical products, and thus reducing the trial-and-error process and achieving the choke design speedups. This paper proposes a comprehensive process for the characterization and modeling of single-phase CM chokes based on finite-element analysis (FEA). By extracting the transmission parameters through 3-D model of choke, both impedance magnitudes and phases of its CM or differential-mode (DM) can be collected. These impedances will then be used to derive the behavioral model. The results are validated experimentally with good agreement up to 100 MHz.