A simulation platform of Switched-mode Power Supplies for EMI filter design

This paper presents a simulation platform of Switched-mode Power Supplies utilizing the characteristic of noise generation and coupling mechanism to predict the noise feature and design EMI filter in flyback converter. The paper also introduces the simulation algorithms which comprise noise source model, filter model, CM circuit model, DM circuit model and the method to obtain EMI spectrum. The bandwidth-effects-FFT computing method is used to analyze the spectrum of noise source, and the identified noise coupling paths are used to build up simulation circuit models. The simulation platform and the models are verified by experimental results. The simulation platform provides a simple and convenient way for EMI filter design of switched-mode power supplies within a certain frequency range.