Study of coupling effects among passive components used in power electronic devices

Modeling the coupling path of conducted EMI in power electronic devices is helpful for designing and debugging of their EMC. To achieve more effective model of EMI coupling path, the coupling effects among passive components should be involved in the model. In this paper, three kinds of coupling effects between two passive components are studied in detail. Based on testing the relationship of each kind of coupling effect and the distance between the two passive components, the paper proposed a two-port model to describe their performance including coupling effects. The tested and simulated results of frequency characteristic of a low-pass two-stage LC fitter show that the two-port model of two passive components is effective.