Abstract
Since the early days in this century, many countries in the world started establishing national standard of electromagnetic compatibility for conducting electromagnetic interference tests on electronic products. In order to comply with the EMC standards, numerous resources are used on repetitive modifications and experiments so that the electronic products can pass the tests. Recently, with the fast development of the computer technology, the use of computer aided engineering in design and analysis has become a major trend. In this study, computer simulations are adopted for analysis of conducted EMI on power supplies with two-stage power factor correction circuits. The models for the circuits in power supplies were established with the help of simulation tools; meanwhile, the pre-stage consists of AC/DC converters with structure in a diode bridge and a boost converter. Moreover, the post-stage consists of a DC/DC converter with voltage regulation circuits in flyback voltage conversion topology. And, crucial parameterization of EMI influences and simplification of circuit models are studied for saving simulation times. Finally, snubber circuit and EMI filter design have been evaluated for study of the effects on power signal noises and power factor enhancement. The goal is to provide a analytical foundation for similar type of power supplies in the industries.