Disturbance direction detection in a power system

1 . A system to determine the direction of a disturbance event in a power system comprising:

a power feed bus for supplying electrical signal; and

an Intelligent Electronic Device coupled to the power feed bus;

wherein the Intelligent Electronic Device is configured to:

capture a first number of cycles of pre-event signals and a second number of cycles of post-event signals for each phase of the power system after detecting the disturbance event;

compute average pre-event power, average pre-event current, and average pre-event voltage from the pre-event signals, and average post-event power, average post-event current, and average post-event voltage from the post-event signals;

determine a single-phase direction of the disturbance event for each phase by comparing changes between the average pre-event power, average pre-event current, and average pre-event voltage and the average post-event power, average post-event current, and average post-event voltage against a predefined threshold to identify data trends, and mapping the data trends to a direction using a direction determination table; and

determine a final direction of the disturbance event based on a combination of the single-phase directions for multiple phases using a final direction determination table.

2 . The system of claim 1 , wherein the final direction determination table defines combinations of single-phase directions for each phase as upstream, downstream, or indeterminate to determine the final direction of the disturbance event.

3 . A method of determining the direction of a disturbance event in a power distribution system comprising:

capturing a first number cycles of pre-event signals for each phase and a second number cycles of post-event signals for each phase after detecting a disturbance event in a measuring point;

measuring the power, current and voltage for each cycle of pre-event signals and post-event signals;

computing the average power, current and voltage for pre-event signals and post-event signals;

identifying the data trend of power, current and voltage of the post-event signals by comparing differences between the average pre-event and post-event values against a predefined threshold;

determining the location of the single-phase disturbance relative to the metering point by mapping the data trends to a direction using a direction determination table; and

determining the final location of the disturbance event based on a combination of the single-phase directions for multiple phases using a final direction determination table.

4 . The method of claim 3 , wherein the second number cycles of post-event signals include 10 cycles of post-event signals captured until the earlier of a specified number of cycles or the end of the disturbance event.

5 . The method of claim 3 , wherein the final direction determination table defines combinations of single-phase directions for each phase as upstream, downstream, or indeterminate to determine the final location of the disturbance.

6 . The method of claim 3 , wherein the measuring the power, current and voltage for each cycle of pre-event signals and post-event signals is performed by a single Intelligent Electronic Device.

7 . The method of claim 3 , wherein the measuring the power, current and voltage for each cycle of pre-event signals and post-event signals is performed by a plurality of Intelligent Electronic Devices.

8 . The method of claim 3 , wherein each of the plurality of Intelligent Electronic Devices network with other Intelligent Electronic Devices.

9 . The method of claim 3 , wherein each of the plurality of Intelligent Electronic Devices perform a system-wide location of the disturbance according to the location information from every Intelligent Electronic Device.