Correlation between the near magnetic field radiated by an EMI filter and its electric working

In this paper, the behavior in radiated mode of an EMI filter used in speed drives is analyzed. It was identified as one of the main sources of magnetic near field radiation. On one hand, the EMI filter is located upstream from the speed drive and is the victim of the other radiation sources of the speed drive. On the other hand, these sources excite its parasitic elements and create new resonance frequencies. By analyzing input impedance and transfer function and magnetic field measurements, we tried to link the resonance frequencies of the amplitude spectra of the radiated magnetic field and the one of the electric characteristics.