Automated synchronization of data between electrical grids

• US 8,467,985 B2
• Filed: 10/31/2008
• Issued: 06/18/2013
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: Schneider Electric USA, Inc. (Schneider Electric SE)
• Original Assignee: Schneider Electric USA, Inc. (Schneider Electric SE)
• Inventors: Bickel, Jon A.
• Primary Examiner(s): Moffat, Jonathan C Teixeira
• Assistant Examiner(s): BETSCH, REGIS J
• Application Number:
  US12/262,802
• Publication Number:
  US 20100111112A1
• Time in Patent Office: 1,691 Days
• Field of Search: 702/75, 307/64
• US Class Current: 702/75
• CPC Class Codes: G06F 16/2358 Change logging, detection, and notification replication G06F16/27
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor

Abstract

A method and system of automatically correlating data measured by monitoring devices that monitor first and second electrical grids. The second electrical grid producing alternating current signals that are electrically isolated from alternating current signals produced by the first electrical grid. An example power monitoring device includes a controller, a first monitoring device interface and a second monitoring device interface. The first monitoring device interface is coupled to a first monitoring device in the first electrical grid and the second monitoring device interface is coupled to a second monitoring device in the second electrical grid. A first counter stores data counts of occurrences from the first electrical grid. A second counter stores data counts of occurrences from the second electrical grid. A synchronization monitoring algorithm automatically synchronizes the first and second counters by associating a data count from the first counter with a data count from the second counter with a time from either the first or second grid corresponding to the occurrence of an event on either the first or the second electrical grid or both.

Claims

1. A method of automatically associating data measured by monitoring devices that monitor independent alternating current electrical grids, comprising:

receiving, at a master synchronization device, first signal data from a first set of power monitoring devices that are monitoring current or voltage outputs for power consumption from a first electrical grid, the first signal data representing at least frequency variations in energy supplied by the first electrical grid and the values of current or voltage outputs from the first set of power monitoring devices, the frequency variations of the first signal data being measured by respective ones of the first monitoring devices for a predetermined number of occurrences;

automatically synchronizing, in the master synchronization device, the frequency variations measured by each of the first monitoring devices and producing a first occurrence counter that counts a periodic occurrence in the synchronized frequency variations associated with the first monitoring devices;

receiving, at the master synchronization device, second signal data from a second set of power monitoring devices that are monitoring current or voltage outputs for power consumption from a second electrical grid, the second electrical grid independent of the first electrical grid and producing alternating current signals that are electrically isolated from alternating current signals produced by the first electrical grid, the second signal data representing at least frequency variations in energy produced by the second electrical grid and the values of current or voltage from the second set of power monitoring devices, the frequency variations of the second signal data being measured by respective ones of the second monitoring devices for a predetermined number of occurrences at a time coincident with a time that the first set of monitoring devices measure the frequency variations in the energy supplied by the first electrical grid;

automatically synchronizing, in the master synchronization device, the frequency variations measured by each of the second monitoring devices and producing a second occurrence counter that counts a periodic occurrence in the synchronized frequency variations associated with the second monitoring devices;

automatically comparing, in the master synchronization device, a first count of the first occurrence counter with a first count of the second occurrence counter, wherein the first count of the first occurrence counter and the first count of the second occurrence counter temporally correspond to an electrical event in the first electrical grid and the second electrical grid; and

determining a relationship between the first signal data and the second signal data by associating the first count of the first occurrence counter and the first count of the second occurrence counter to collect the first and second signal data and the first and second occurrence counters for analysis of the first and second signal data independent of changing power supplied by the first and second electrical grids.

2. The method of claim 1, wherein the alternating current produced by the first electrical grid is electrically isolated from the alternating current produced by the second electrical grid via an intervening uninterruptible power supply, a motor-generator set, or a diesel-generator set.

3. The method of claim 1, wherein the number of occurrences associated with the first monitoring devices is a number of cycles of the alternating current signals produced by the first electrical grid, and the number of occurrences associated with the second monitoring devices is a number of cycles of the alternating current signals produced by the second electrical grid.

4. The method of claim 1, wherein the first and second electrical grids both supply alternating current signals to a data center.

14. The method of claim 3, wherein the first electrical grid is defined as part of an electrical utility grid interconnection, and wherein the second electrical grid is electrically isolated from the first electrical grid by an intervening uninterruptible power supply, a motor-generator set, or a diesel-generator set, and wherein the first or the second electrical signals or both supply alternating current signals to a data center.

15. The method of claim 1, further comprising:

associating the first count of the first occurrence counter and the first count of the second occurrence counter in a first entry of a time data table;

automatically comparing, in the master synchronization device, a second count of the first occurrence counter with a second count of the second occurrence counter, wherein the second count of the first occurrence counter and the second count of the second occurrence counter temporally correspond to a second electrical event in the first electrical grid and the second electrical grid;

associating the second count of the first occurrence counter and the second count of the second occurrence counter in a second entry of the time data table; and

comparing the historical relationship between the first signal data and the second signal data through the first entry and the second entry of the time data table.

16. The method of claim 15, further comprising:

continuing to compare the historical relationship between the first signal data and the second signal data through subsequent entries of the time data table.

5. A power monitoring device for associating data between a first and second electrical grid, the second electrical grid producing alternating current signals that are independent of and electrically isolated from alternating current signals produced by the first electrical grid, the power monitoring device comprising:

a controller;

a first monitoring device interface coupled to a first monitoring device in the first electrical grid, the first monitoring device monitoring current or voltage outputs for power consumption from the first electrical grid;

a second monitoring device interface coupled to a second monitoring device in the independent and electrically isolated second electrical grid, the second monitoring device monitoring current or voltage outputs for power consumption from the second electrical grid;

a first counter corresponding to data counts of occurrences in energy supplied by the first electrical grid and measured by the first monitoring device;

a second counter corresponding to data counts of occurrences in energy supplied by the second electrical grid and measured by the second monitoring device at a time coincident with a time that the occurrences from the first electrical grid are measured by the first monitoring device; and

a synchronization monitoring algorithm automatically synchronizing the first and second counters by associating a data count from the first counter with a data count from the second counter with a time corresponding to the occurrence of an electrical event on both the first and the second electrical grids to collect the first and second signal data and the first and second occurrence counters for analysis of the first and second signal data independent of changing power supplied by the first and second electrical grids, the synchronization monitoring algorithm being used to determine a relationship between the first counter and the second counter.

6. The device of claim 5, wherein the alternating current produced by the first electrical grid is electrically isolated from the alternating current produced by the second electrical grid via an intervening uninterruptible power supply, a motor-generator set, or a diesel-generator set.

7. The device of claim 5, wherein the data counts of occurrences from the first electrical grid is a number of cycles of the alternating current signals produced by the first electrical grid, and the data counts of occurrences from the second electrical grid is a number of cycles of the alternating current signals produced by the second electrical grid.

8. The device of claim 7, wherein the number of cycles associated with the first electrical grid represents a number of zero crossings by a current or voltage signal monitored by the first monitoring device in the first electrical grid.

9. The device of claim 5, wherein the first or second monitoring device interface are mounted on a card module detachable from the controller, and the master synchronization algorithm is stored in a memory.

10. The device of claim 5, wherein the first and second monitoring device interface are mounted on a card module detachable from the controller, and the master synchronization algorithm is stored in a memory coupled to the controller.

17. The device of claim 5, wherein the synchronization monitoring algorithm is configured to automatically synchronize the first and second counters by associating a second data count from the first counter with a second data count from the second counter with a time corresponding to the occurrence of a second electrical event on both the first and the second electrical grids;

the device further comprising;

a time data table for storing a first entry corresponding to the association of the data count from the first counter with the data count from the second counter corresponding to the electrical event and a second entry corresponding to the association of the second data count from the first counter with the second data count from the second counter corresponding to the second electrical event;

wherein the synchronization monitoring algorithm is configured to compare the historical relationship between the first counter and the second counter through the first entry and the second entry of the time data table.

18. The device of claim 17, wherein the synchronization monitoring algorithm is configured to continue comparing the historical relationship between the first counter and the second counter through subsequent entries in the time data table.

11. A non-transitory machine readable medium having stored thereon instructions for associating data measured from a first and a second electrical grid, the second electrical grid producing alternating current signals that are independent of and electrically isolated from alternating current signals produced by the first electrical grid, comprising machine executable code, which when executed by at least one machine, causes the machine to:

receive first signal data from a first power monitoring device monitoring current or voltage outputs for power consumption from the first electrical grid, the first signal data representing frequency variations in energy supplied by the first electrical grid and the values of current or voltage outputs from first power monitoring device, the frequency variations of the first signal data being measured by the first monitoring device for a predetermined number of occurrences;

receive second signal data from a second power monitoring device monitoring current or voltage outputs for power consumption from the independent and electrically isolated second electrical grid, the second signal data representing at least frequency variations in energy produced by the second electrical grid and the values of current or voltage from the second set of power monitoring devices, the frequency variations of the second signal data being measured by the second monitoring device for a predetermined number of occurrences at a time coincident with a time that the first monitoring device measures the frequency variations in the energy supplied by the first electrical grid;

determine a first occurrence count corresponding to a perturbation measured by the first monitoring device;

determine a second occurrence count corresponding to the perturbation measured by the second monitoring device;

associate the first occurrence count with the second occurrence count based on a time measurement of the perturbation occurring in both the first and the second electrical grids; and

determine a relationship between the first signal data and the second signal data using the associated first and second occurrence counts to collect the first and second signal data and the first and second occurrence counters for analysis of the first and second signal data independent of changing power supplied by the first and second electrical grids.

12. The machine readable medium of claim 11, wherein the alternating current produced by the first electrical grid is electrically isolated from the alternating current produced by the second electrical grid via an intervening uninterruptible power supply, a motor-generator set, or a diesel generator set.

13. The machine readable medium of claim 11, wherein the number of occurrences associated with the first monitoring devices is a number of cycles of the alternating current signals produced by the first electrical grid, and the number of occurrences associated with the second monitoring devices is a number of cycles of the alternating current signals produced by the second electrical grid.

19. The machine readable medium of claim 11, further comprising instructions that cause the at least one machine to:

store the association of the first occurrence count and the second occurrence count in a first entry of a time data table;

determine a third occurrence count corresponding to a second perturbation measured by the first monitoring device;

determine a fourth occurrence count corresponding to the second perturbation measured by the second monitoring device;

associate the third occurrence count with the fourth occurrence count based on a time measurement of the second perturbation occurring in both the first and the second electrical grids;

store the association of the third occurrence count and the fourth occurrence count in a second entry of the time data table; and

compare the historical relationship between the first signal data and the second signal data through the first entry and the second entry of the time data table.

20. The machine readable medium of claim 19, further comprising instructions that cause the at least one machine to:

continue to compare the historical relationship between first signal data and the second signal data through subsequent entries of the time data table.