Experimental Investigation of a π–L EMI Filter for Conducted Noise Suppression in a Dual Active Bridge Converter

High-frequency dual active bridge (DAB) converters used in electric vehicle (EV) charging and bidirectional energy conversion systems often generate severe conducted electromagnetic interference (EMI), including common-mode (CM) and differential-mode (DM) noise, which complicates compliance with automotive EMI standards. This paper proposes an impedance-based EMI filter design methodology for a high-frequency voltage-mode controlled DAB converter. A passive π–L filter topology is analytically designed to simultaneously suppress CM and DM noise while considering converter–filter interaction and stability constraints. Unlike conventional trial-and-error approaches, the proposed method enables predictable broadband attenuation through impedance-oriented analysis. A 500 W hardware prototype operating between a 60 V source and a 48 V battery is developed to validate the proposed approach under single-phase-shift control, achieving a peak efficiency of 97.6%. Conducted emissions are evaluated using a line impedance stabilization network (LISN) in accordance with CISPR 25 Class 5 standards over the frequency range of 150 kHz–30 MHz. Experimental results show that the optimized filter achieves full EMI compliance with significant attenuation margins, while maintaining high conversion efficiency. The close agreement between analytical and experimental results demonstrates the effectiveness and practical applicability of the proposed EMI-aware DAB design methodology for high-density Grid-to-Battery and Battery-to-Grid systems.