Method for power quality summary and trending

• US 7,050,916 B2
• Filed: 11/05/2003
• Issued: 05/23/2006
• Est. Priority Date: 11/05/2003
• Status: Active Grant

• Current Assignee: Square D Company (Schneider Electric SE)
• Original Assignee: Square D Company (Schneider Electric SE)
• Inventors: Bickel, Jon A., Curtis, Larry E.
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): PRETLOW, DEMETRIUS R
• Application Number:
  US10/702,146
• Publication Number:
  US 20050114057A1
• Time in Patent Office: 930 Days
• Field of Search: 702/60, 702/61, 702/62, 702/64, 702/65, 702/81
• US Class Current: 702/81
• CPC Class Codes: G01R 19/2513 Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging

Abstract

A system for accumulating and evaluating electromagnetic phenomena of at least one power quality category of a power distribution system, using a circuit monitor or processing system that summarizes and trends electromagnetic phenomena. The system provides for expressing the power quality index as a single number for each power quality category present and for combining multiple power quality indices into a single overall power quality index.

Claims

1. A system for accumulating and evaluating electromagnetic phenomena of multiple power quality categories of a power distribution system, comprising a circuit monitor coupled to said power distribution system and accumulating data representing said electromagnetic phenomena, said circuit monitor being programmed to determine a power quality index for each of said multiple power quality categories, and a single overall power quality index for all of said power quality categories, said power quality indices for power quality categories involving steady state conditions being based on the percentage of time said conditions exist during an evaluation period and the severity of such conditions, and said power quality indices for power quality categories involving abnormal events being based on the number of such events that occur during an evaluation period and the severity of such events.

2. The system of claim 1 wherein said single overall power quality index for all of said power quality categories is the lowest of said power quality indices for said power quality categories.

3. The system of claim 1 wherein said power quality indices for power quality categories are based at least in part on data collected from networked circuit monitors.

4. The system of claim 3 wherein said networked circuit monitors include branch circuit monitors.

5. A system for accumulating and evaluating electromagnetic phenomena of multiple power quality categories of a power distribution system, comprising a circuit monitor coupled to said power distribution system and accumulating data representing said electromagnetic phenomena, said circuit monitor being programmed to determine a power quality index for each of said multiple power quality categories, and a single overall power quality index for all of said power quality categories that is a weighted average of said power quality indices for said power quality categories, said weighted average being based on the nature of the power distribution facility and the load types in said facility.

6. The system of claim 5 wherein said weighted average is based on the nature of the power distribution facility and the load types in said facility.

7. The system of claim 5 wherein said single overall power quality index for all of said power quality categories is the lowest of said power quality indices for said power quality categories.

8. The system of claim 5 wherein said power quality indices for power quality categories are based at least in part on data collected from networked circuit monitors that include branch circuit monitors.

9. A method of accumulating and evaluating data representing electromagnetic phenomena of multiple power quality categories of a power distribution system, comprising

determining an individual power quality index for each of said multiple power quality categories, and

determining an overall power quality index for all of said individual power quality indices, weighting said at least one power quality category according to the load type present, said power quality indices for power quality categories involving steady state conditions being based on the percentage of time said conditions exist during an evaluation period and the severity of such conditions, and said power quality indices for power quality categories involving abnormal events being based on the number of such events that occur during an evaluation period and the severity of such events.

10. The method of claim 9 wherein said single overall power quality index for all of said power quality categories is the lowest of said power quality indices for said power quality categories.

11. The method of claim 9 wherein said power quality indices for power quality categories are based at least in part on data collected from networked circuit monitors.

12. The method of claim 9 wherein said power distribution system comprises a system of networked circuit monitors, wherein each of said circuit monitors accumulates data representing said electromagnetic phenomena, and is programmed to determine said power quality index for each of said multiple power quality categories, and said single overall power quality index for all of said power quality categories.

13. A method of accumulating and evaluating data representing electromagnetic phenomena of multiple power quality categories of a power distribution system, comprising

determining an individual power quality index for each of said multiple power quality categories, and

determining an overall power quality index for all of said individual power quality indices weighting said at least one power quality category according to the load type present that is a weighted average of said power quality indices for said power quality categories, said weighted average being based on the nature of the power distribution facility and the load types in said facility.

14. The method of claim 13 wherein said weighted average is based on the nature of the power distribution facility and the load types in said facility.

15. The method of claim 13 wherein said single overall power quality index for all of said power quality categories is the lowest of said power quality indices for said power quality categories.

16. The system of claim 13 wherein said power quality indices for power quality categories are based at least in part on data collected from networked circuit monitors that include branch circuit monitors.