Radiation and disturbance mitigation in PLC networks

This paper presents the last results obtained over a four-year, in-depth study of the mechanisms of parasitic EMC emissions generated by an in-house PLC network. Common mode current generation and its effect on the parasitic field emissions is the core of this paper. Numerical simulations and experimental measurements of a 1:1 scale representative room built on a CISPR 16 compliant Open Area Test Site, followed by a measurement campaign in real electrical house network, allowed us to develop devices, called "plugins" in the following document. The latest, as it will be shown, have proven their capability in term of radiation reduction. Our results indicate that the common-mode current generated along the power-line cables and its associated magnetic field, are mainly due to electrical asymmetries. These one can be reduced by the insertion of the above-mentioned plugins in wall outlet and reduce as well the magnetic field from 6 to 10 dB. A key factor of this study has been the development of a statistical measurement method that has reduced by a 4 fold factor the field measurement time, at the cost of only a 3dB max error. This method is able to overcome the high variability of the magnetic field in a determined space which makes difficult to evaluate the disturbance potential of a setup from measurements of the magnetic field at a single point.