Harmonic component extraction algorithm of conducted emission spectrum based on EMD and periodic extensional model

Harmonic component is critical element in spectrum analysis of electromagnetic compatibility (EMC), this paper proposes a method of using empirical mode decomposition (EMD) to extract the harmonics from conducted emission (CE) spectrum, which improves the grey-periodic extensional model. Intrinsic mode function (IMF) was used to replace the residual sequence of grey prediction model, first establishing the periodic extensional model of the first IMF (IMF1), then extract its optimal period according to analysis of variance, and finally get the fundamental frequency of harmonic based on the sampling interval, then find the source of harmonics so that to guide the EMC design and rectification.