Designing a power-line-communication-based LoM protection concept with application of software-defined radios

Islanding condition in an electricity distribution grid occurs when a distributed generator (DG) continues to power parts of the grid, when connection with the power utility is lost. This situation can cause severe and fatal personal injuries, equipment damage, and power quality degradation. In this paper, communication-based anti-islanding, that is, a loss-of-mains (LoM) protection system for electricity distribution grids in Finland is proposed and studied. The LoM protection concept is based on power line communication (PLC). Detailed analyses of the electrical grid environment, channel characteristics, and a suitable operational frequency band and range for the PLC are presented. Software-defined radios (SDRs) are applied as a flexible platform in designing and testing a PLC-based anti-islanding protection system. Laboratory tests are carried out, the results are analyzed, and recommendations for future studies are made.