Design Approach to Passive and Active Hybrid Integrated EMI Filters for High-Frequency Converters

Abstract:
Incorporating an active EMI filter (AEF) into a passive EMI filter (PEF) significantly reduces the dependence on passive components, which is particularly evident in the considerable reduction in the size of the CM chokes. This paper not only examines the impact of AEFs on the attenuation of passive EMI filters and the resulting reduction in CM choke size, but also analyzes the conducted disturbances in highfrequency converters. In addition, AEFs, both single-phase and three-phase, are developed using Voltage Sense Current Inject (VSCI) Feedback (FB)-topology. Simulation and measurement results show that the integrated active EMI-filter effectively suppresses conducted common-mode (CM) emissions by about 15 to 23 dB in the frequency range from 150 kHz to 1 MHz.