Study on an accurate calculation of the conducted EMI noise of the power converters

The efficient reduction of EMI noise generated by power converters has been an indispensable technology. In order to meet the requirements of CISPR22, EMI filters have to be equipped with power converters. It is widely known that an EMI filter can be designed more optimally if the designer could know its inherent EMI noise in advance. This paper presents an accurate simulation method for the conducted EMI noise in power converters and verifies its effectiveness through experiments. By using the results, it is possible to reduce the design time for the power converter as well as the volume of the converter. In addition, a novel common-mode current reduction method in which only two small capacitors are added to the inverter is proposed.