KETEP 세계에너지시장정보

1. A method of detecting a phase difference between service nodes in an alternating current (AC) power line communications network, comprising:
at a first service node connected to a first phase of a plurality of phases in a power distribution grid, measuring a local zero crossing gap between a time at which the voltage at the first phase crosses a reference level and the start of a communications frame;
receiving over the power line communications, from a second service node, data corresponding to a zero crossing gap at the second service node;
deriving a zero crossing gap interval value corresponding to a difference between the received zero crossing gap and the local zero crossing gap; and
comparing the zero crossing gap interval value with one or more threshold values to identify a phase relationship between the first service node and the second service node.