Evaluation and Comparison of Conducted EMI in Three Full-Bridge DC-DC Switching Converters

Switching power supplies is one of the major causes of electromagnetic interference in electronic devices due to the fast transient of voltages and currents. Full bridge switching converters are commonly used for medium and high power application. High electromagnetic interference takes place due to the large number of active elements in full bridge converter. Soft switching methods are able to reduce EMI in switching mode power supplies. In this paper, the effect of the use of the phase shift control and also use a resonant series schemes to implement soft switching conditions in the full bridge converter is investigated from EMI viewpoint. The modeling of conducted EMI in phase shifted DC-DC full bridge converter, series resonant full bridge converter and conventional hard switching full bridge converter are presented and compared using CST studio software. The modeling results indicate that the series resonant full bridge converter has a better performance than the phase shifted full bridge switching converter from EMI viewpoint.