Power Line EMI Filter Design of Power Converters to Meet the Conducted Emission Specifications of MIL-STD-461G

This paper presents the investigation and mitigation of the conducted emissions generated by the power converter in any system with and without an EMI filter to meet the EMC limits. The conducted emissions of the converter are measured with a standard setup, and depending upon the qualification limit line (MIL-STD-461G standard), the insertion loss requirement and cutoff frequency are calculated for differential mode and typical mode emissions. The conductions will exceed the limit line w.r.t the general power converter operation, and these emissions will travel towards the power source or grid. An EMI filter is designed to mitigate this by selecting the appropriate L and C elements. This EMI filter is placed at the input of the power converter to mitigate the conducted emission from the converter. The EMI filter and the power converter are designed and validated in the laboratory under different load conditions and different frequencies of operation.