Research on the Transmission Characteristics of Low-voltage Power Line Communication Channel

Low-voltage power line communication (PLC) is an important communication technology in smart grid, it can realize bi-direction end-to-end data transmission reliably between intelligent device and end-user. To ensure the symmetry of downlink and uplink, there are well documented that bi-direction amplitude-frequency responses of a low-voltage wideband PLC channel are same provided that the source and load impedances are equal, the phase-frequency response is not studied. In this paper, the bi-direction amplitude- and phase-frequency responses of low-voltage PLC channel based on power line transmission theory are respectively simulated for different power line network topology structures with equal and unequal source and load impedances. The results show that the PLC system is completely symmetrical (consistent bi-direction amplitude- and phase-frequency responses) as long as it simultaneously satisfies two conditions which are the symmetrical network topology structures and equal source and load impedances.