Patent ID: 8081726

Claim:
A system for synchronizing a plurality of monitoring devices in a power system to a common time reference, comprising: a time synchronization device that includes a reference clock, a signal generator, and a first controller programmed to cause the signal generator to generate a synchronization signal at periodic time intervals that are synchronized with the reference clock, the signal generator coupling the synchronization signal over an energized power conductor carrying a current or voltage that oscillates at a fundamental or nominal frequency of the power system, the synchronization signal being distinct from the current or voltage carried by the energized power conductor and having a frequency greater than the fundamental or nominal frequency of the power system and a magnitude that exceeds a noise floor associated with the power system; and a monitoring device coupled to the energized power conductor, the monitoring device including a detection module that detects the current or voltage carried by the energized power conductor, a communications interface communicatively coupled to a remote system that is remote from the monitoring device and the time synchronization device, and a second controller coupled to a memory, electrical data indicative of the detected current or voltage being stored in the memory, the second controller being programmed to: detect at least the frequency or the magnitude of the synchronization signal and, in response thereto, to store data in the memory indicative of the detection of the synchronization signal; synchronize the electrical data with the reference clock by adjusting a time of an on-board clock or a cycle counter in the monitoring device responsive to the detected synchronization signal; and transmit, via the communications interface, the synchronized electrical data to the remote system.