EMI analysis and evaluation of an improved flyback converter

Switching power converters are sources of noise for sensitive circuits. Converters should comply with electromagnetic compatibility (EMC) rules so that the electromagnetic interference (EMI) caused by switching cannot interfere with the normal operation of adjacent circuits and also the converter itself. The produced interference can be in the form of conduction or radiation. In this paper, some techniques are used in switching converters to suppress EMI with emphasis on the conduction form. EMI analysis and evaluation of a conventional flyback converter is achieved by simulation and experimental results. In addition to evaluating some EMI suppression techniques, the main objective of this paper is to improve EMI in the topology design stage. In addition to the efficiency improvement, the effectiveness of some EMI reduction techniques is shown by practical implementation.