Characterization of the Potential Effects of EMC Filters for Power Converters on Narrowband Power Line Communications

Electromagnetic Compatibility (EMC) filters are one of the main solutions for dealing with the disturbances generated by power inverters. However, they show series/parallel resonances that introduce variations in the impedance seen from the grid. Consequently, in some cases, these filters have low impedances at resonance frequencies, which can affect Narrowband Power Line Communications (NB-PLC) due to notching effects. For that reason, the potential effects of four EMC filters on NB-PLC have been studied. Laboratory trials in a controlled environment have been carried out, in which the attenuation and the Signal-to-Noise Ratio (SNR) thresholds that define the communication’s quality have been studied. The results presented in this paper show that, although the variations of the channel frequency response are not selective enough to degrade the communication thresholds, the attenuation measured when the filter is connected near the receiver might be sufficiently high to be critical for the communications in some situations. Therefore, EMC filters might have a negative impact on NB-PLC that had not been previously considered.