Radiated EMI Prediction in Power Converters with Power Cables Based on Cable Antenna Voltage Gain Extraction

Radiated Electromagnetic interference (EMI) issue becomes more and more important in power electronics systems in recent years. To fully understand the generation and propagation mechanism of the radiated EMI, radiated EMI modeling and prediction techniques are very important. In this article, an active-clamp Flyback converter with long power cables is taken as an example, the radiated EMI model is developed, a step-by-step guide to predict the radiated EMI spectrum is proposed, some important issues are pointed out for EMI prediction. The predicted EMI based on the proposed guide can match the measured EMI very well within 6dB error in the range of 30MHz − 230MHz based on EN55032 3m class B standard.