Power converters in electricity distribution networks have become very popular due to the dramatic increase in the installation of renewable energy generation systems. However, these systems generate a non-negligible quantity of conducted emissions, i.e. high frequency disturbances caused by the switching of the power converter valves. These disturbances are concentrated in the frequency range 2 kHz ÷ 500 kHz, and can compromise the correct functioning of the increasingly widespread communication systems in distribution networks, such as those based on power line technology. These problems require a detailed study of the distribution networks also in that frequency range to understand how conducted emissions generated by converters propagate in the distribution network.
For these reasons, this report presents a study on the propagation of conducted emissions in a low voltage network, through simulations in the time and frequency domain. The network implemented as a case study represents a typical low voltage network with distributed photovoltaic generation systems, loads, power factor correction capacitors, lines and a secondary substation. Models for each of these network components were implemented in the frequency range of interest. The simulation activity revealed which parameters can most influence the propagation of conducted emissions in a distribution network. Once these models had been implemented, several simulations were carried out to investigate the influence of some network parameters such as the length of the lines, the presence/absence of power factor correction capacitor banks. The results obtained provided general information on how conducted emissions propagate in a typical distribution network.