Study of the Conducted Emissions of an SMPS Power Converter from 2 to 150 kHz

In this paper the electromagnetic interference generated by an SMPS power converter in the 2-150 kHz frequency range is studied. Measurement and evaluation of the conducted emissions are carried out in the time domain and transformed into the frequency domain by means of the Short-Time Fourier transform. In the absence of current coordinate electromagnetic compatibility regulations for this frequency range, the aim is to find out whether measurement and processing settings of the time-domain electromagnetic interference may have an impact on the conducted emission results in the frequency domain. A prototype of an SMPS battery charger power converter for electric vehicles is used in the experiments. The results show that both measurement and processing settings may affect the conducted emissions.