Novel Single-Stage and Two-Stage Integrated Magnetic Chokes for DC-Side EMI Filter in Motor Drive Applications

Passive electromagnetic interference (EMI) filters are widely used to suppress the conducted common-mode (CM) and differential-mode (DM) noise emissions. However, these passive EMI filters occupy a large PCB area and volume, reducing the power density of the converters. This article proposes two novel integrated magnetic chokes for single-stage and two-stage EMI filters. Magnetic equivalent circuits for both the proposed integrated EMI chokes have been presented to estimate the inductance and magnetic flux density of the chokes. The flux distribution in the proposed integrated chokes for the DM and CM current excitation is validated through ANSYS simulation results. The performance of the proposed integrated chokes is experimentally presented and validated on a three-phase SiC inverter-fed Brushless DC (BLDC) motor drive. The proposed integrated choke for the single-stage EMI filter and the two-stage EMI filter reduces the PCB area by 37% and 36%, respectively, and the filter box volume is reduced by 34% and 9%, respectively, when compared to their equivalent conventional EMI filters. The abovementioned reduction has been achieved without significantly increasing the weight of the filter as compared to the weight of conventional EMI filters.