Toroidal-EE-Based Integrated Common-mode Choke for dc-side EMI filter

Abstract

In literature, the use of passive electromagnetic interference (EMI) filters is extensively researched to not only restrain the common-mode (CM) noise but also the differential-mode (DM) noise. Although the CM and DM chokes are simple to design, reliable, and do not need an auxiliary power supply, they increase the overall volume and reduce the power density of a power converter. Hence, this paper presents a novel integrated choke that offers higher DM impedance than the traditional CM choke by maintaining the same volume, when compared to the traditional CM choke. The calculation of CM inductance, as well as DM inductance of the proposed integrated filter topology, is presented along with a small signal measurement using an impedance analyzer. The proposed EMI filter performance is verified on a three-phase silicon carbide (SiC) fed brushless dc (BLdc) motor.