Fast prediction for conducted EMI in flyback converters

The flyback switched mode power supply often fails in electromagnetic compatibility (EMC) because of the easily aroused conducted electromagnetic interference (EMI). However, the measurement of conducted EMI during initial compliance tests requires strict test environments and expensive facilities, this makes the prediction of EMI important. This paper presents a time domain simulation method to predict the conducted EMI of a flyback converter before prototyping. The CST PCB Studio is utilized to extract parasitic parameters of a printed circuit board (PCB) based on 2D field solver and perform total circuit simulation. Experimental results validate that the presented modeling method is efficient and fast to predict EMI.