Alternate Filter Structures for Circulating Current and Conducted Noise Mitigation

This letter presents a family of filter topologies for circulating current and conducted emissions mitigation, applicable with parallel and interleaved converters. The proposed alternative topologies are aimed at reducing the overall filter volume using magnetic integration or topological variations. In general, they are classified into three distinct forms, namely in-directly coupled, localized, and direct phase to phase coupled topologies. The emphasis is on pure common mode harmonics but can be extended to differential mode components as well. A quantitative comparison among the variants is made on the basis of simulation/experimental findings and references aiding the designer to select the structure best suited for a particular application.