High power density EMI mitigation in power electronics converters: Active and integrated solutions

Traditional bulk passive EMI filters are the “necessary evil” for modern power electronics systems yet they are also the bottle-neck for the improvement of power density. This limitation is caused by the low power-density of passive components themselves and the conventional passive components are structurally optimized when assembled together. Use of active circuits and integration approach in EMI noise filtering have been proven to be effective in shrinking the size and weight of traditional EMI filters. This paper presents an overview of the latest works in the area of active EMI filtering, passive integration and a combination of both techniques. The paper compares passive volume reduction with active EMI filtering and summaries a list of materials and processes involved in the passive integration techniques. These new approaches provide potential high density solutions for EMI mitigation in power electronics converters.