Phase determination in smart grid networks

A tangible, non-transitory, computer-readable media having software encoded thereon, the software when executed by a processor operable to:

• transmit, in a low power and lossy network (LLN) comprising one or more interfaces and a plurality of nodes, to a plurality of nodes by a first node, data indicating a time corresponding to a last zero crossing of the power supplied to the first node;
• receive, from a particular node of the plurality of nodes, data from the first node comprising data indicating the time corresponding to the last zero crossing of the power supplied to the first node;
• determine, by the particular node, a time since a last zero crossing of the power supplied to the particular node;
• calculate, by the particular node, a differential phase value between the first node and the particular node based on the difference between the last zero crossings of the power supplied to the first node and the power supplied to the particular node;
• transmit, by the particular node to the first node, the calculated differential phase value between the first node and the particular node;
• receive the calculated differential phase value between the first node and the plurality of nodes;
• receive a calculated differential phase value between each of the plurality of nodes;
• and
• determine an absolute phase value of one or more of the plurality of nodes relative to the phase value of the first node based on the received differential phase values of each of the one or more of the plurality of nodes and the absolute phase value of the first node.

A system, comprising:

• a processor adapted to execute one or more processes;
• and
• a memory configured to store a process executable by the processor, the process when executed operable to:
• transmit, in a low power and lossy network (LLN) comprising one or more interfaces and a plurality of nodes, to a plurality of nodes by a first node, data indicating a time corresponding to a last zero crossing of the power supplied to the first node;
• receive, from a particular node of the plurality of nodes, data from the first node comprising data indicating the time corresponding to the last zero crossing of the power supplied to the first node;
• determining, by the particular node, a time since a last zero crossing of the power supplied to the particular node;
• calculating, by the particular node, a differential phase value between the first node and the particular node based on the difference between the last zero crossings of the power supplied to the first node and the power supplied to the particular node;
• transmitting, by the particular node to the first node, the calculated differential phase value between the first node and the particular node;
• receive the calculated differential phase value between the first node and the plurality of nodes;
• receive a calculated differential phase value between each of the plurality of nodes;
• and
• determine an absolute phase value of one or more of the plurality of nodes relative to the phase value of the first node based on the received differential phase values of each of the one or more of the plurality of nodes and the absolute phase value of the first node.