On Common-Mode and RF EMI in a Low-Voltage DC Distribution Network

This paper addresses common-mode (CM) and radio frequency (RF) electromagnetic interferences (EMI) in a converter-fed low-voltage direct current (LVDC) distribution research network. The LVDC distribution is a novel approach to public electricity distribution, and a research site is set up to enable comprehensive studies concerning the LVDC distribution. Because the customers in the LVDC system are supplied with customer-end inverters (CEI), CM and RF EMI generated by the CEIs have to be analyzed. To this end, common-mode currents in the DC network and the customer-end networks are studied by on-site measurements. The objective is to determine whether there are disturbances that exceed the requirements of the standards or whether the CM current could cause safety issues in the converter-fed user-end network. In the DC network, the effect of the CM current on the feasibility of power line communication (PLC) in a DC network is analyzed. Finally, RF disturbances are measured and discussed.