Impact of Output Terminations on Conducted Emissions Evaluation of Interface Converters

This paper provides an analysis of the factors influencing the conducted emissions of interface converters, which are of increasing importance for the design and implementation of microgrids. Of particular interest herein is the approach selected for terminating the output port of such converters during qualification testing procedures. Current emissions standards provide considerable flexibility in the handling of output ports for such converters. This study provides a theoretical analysis of an interface converter consisting of a SiC-based single-phase inverter in a custom-built testbed for evaluating conducted emissions. The accompanying analysis demonstrates that the selection of output terminations plays a significant role in determining the resulting emissions, with a difference of up to 40 dB observed in the relevant emissions metrics for different configurations of output terminations. Overall, this study highlights the need to reevaluate the requirements of current emissions standards with the accelerating adoption of wide-bandgap semiconductors due to the increased high-frequency content in systems implemented with this technology.