Patent ID: 8082367
Filing Date: 2011-12-20
Classification: H04J

Abstract:
1. A method of synchronizing respective clocks of intelligent electronic devices (IEDs) in a utility monitoring system, comprising: receiving, at a controller over a network, respective signal data representing frequency or amplitude or phase variations in a characteristic of a utility measured by each of a master IED and a target IED; automatically determining, based on a correlation algorithm applied to the signal data from the master and target IEDs, a difference between a first occurrence of a point in the signal data measured from the master IED and a second occurrence of the same point in the signal data measured from the target IED; determining, based on the difference, time differential data indicative of a time amount by which a target clock of the target IED leads or lags a master clock of the master IED; communicating the time differential data to the target IED to cause the target IED to adjust the target clock by the time amount; determining whether a temperature of the target IED has changed compared to a previous temperature reading; and if the determining whether the temperature has changed results in a temperature change, adjusting the target clock based on the temperature change.