System and method for detecting flicker in an electrical energy supply

• US 6,269,316 B1
• Filed: 11/30/1998
• Issued: 07/31/2001
• Est. Priority Date: 10/22/1996
• Status: Expired due to Term

• Current Assignee: Elster Electricity LLC (Honeywell International Inc.)
• Original Assignee: ABB Power T&D Co Inc (ABB Limited)
• Inventors: Hemminger, Rodney C., Holdsclaw, Scott T., Munday, Mark L., Hubbard, Vick A.
• Primary Examiner(s): Hilten, John S.
• Assistant Examiner(s): Tran, Mylinh T.
• Application Number:
  US09/201,294
• Time in Patent Office: 974 Days
• Field of Search: 702/61, 702/65
• US Class Current: 702/61
• CPC Class Codes: G01R 19/2513 Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G01R 22/00 Arrangements for measuring time integral of electric power or current, e.g. electricity meters

Abstract

A system and method for detecting a flicker of electrical energy provided via a service type to an energy meter. The system comprises a memory for storing a respective voltage threshold for each different service type; a digital signal processor for measuring a respective phase voltage for each meter element of the energy meter; and a microcontroller for retrieving the voltage threshold for the service type from the memory and comparing the measured phase voltage to the voltage threshold to determine an occurrence of flicker.

Claims

1. A system for detecting a flicker in electrical energy provided via a service type to an energy meter having at least one meter element, comprising:

storage means for storing a respective voltage threshold for each of at least one service type;

means for measuring a respective phase voltage for each of said meter elements; and

means for retrieving said voltage threshold for the service type from said storage means and comparing said measured phase voltage to said voltage threshold to determine an occurrence of said flicker.

2. The system according to claim 1, further comprising memory means for recording a duration for said flicker.

3. The system according to claim 2, wherein said storage means and said memory means comprise an EEPROM.

4. The system according to claim 1, wherein said means for measuring comprises a digital signal processor (DSP).

5. The system according to claim 1, wherein said means for retrieving and comparing comprises a microcontroller.

6. The system according to claim 1, furter comprising an indicator and means for activating said indicator responsive to the occurrence of said flicker.

7. The system according to claim 1, further comprising display means for indicating the occurrence of said flicker.

8. The system according to claim 1, wherein said storage means is programmable to change said voltage thresholds.

9. The system according to claim 1, wherein each said voltage threshold is responsive to the service type.

10. The system according to claim 1, wherein the service type is one of single phase and multiphase.

11. The system according to claim 10, wherein said flicker is checked for each phase when the service type is multiphase.

12. The system according to claim 11, wherein each phase of said multiphase service type has a respective voltage threshold.

13. The system according to claim 1, further comprising means for determining a duration of said flicker.

14. The system according to claim 13, wherein said means for determining said duration comprises a counter for counting a number of consecutive clock cycle occurrences of said flicker.

15. The system according to claim 13, wherein when said duration is greater than a first predetermined number and less than a second predetermined number, it is determined that said flicker has occurred, and when said duration is one of not greater than said first predetermined number and not less than said second predetermined number, it is determined that said flicker has not occurred.

16. The system according to claim 15, further comprising a glitch counter that is incremented when it is determined that said flicker has occurred.

17. The system according to claim 15, firther comprising a flicker event log for storing flicker information of said flicker.

18. The system according to claim 17, wherein said information comprises a phase, a date, and a time when said flicker occurred.

19. An electronic processor-implemented process for detecting a flicker in electrical energy provided via a service type to an energy meter having at least one meter element, comprising the steps of:

storing in a first memory a respective voltage threshold for each of at least one service type;

measuring a respective phase voltage for each of said meter elements;

retrieving said voltage threshold for the service type from said memory; and

comparing said measured phase voltage to said voltage threshold to determine an occurrence of said flicker.

20. The process according to claim 19, further comprising the step of recording in a second memory a duration for said flicker.

21. The process according to claim 20, wherein said first memory and said second memory comprise an EEPROM.

22. The process according to claim 19, firer comprising the step of activating an alarm responsive to the occurrence of said flicker.

23. The process according to claim 19, fuirther comprising the step of displaying an indication indicating the occurrence of said flicker.

24. The process according to claim 19, wherein the service type single phase.

25. The process according to claim 24, wherein the service type multiphase, and further comprising the step of checking each phase of a multiphase service type.

26. The process according to claim 25, wherein each phase of said multiphase service tppe has a respective voltage threshold.

27. The process according to claim 19, further comprising the step of determining a duration of said flicker.

28. The process according to claim 27, further comprising the steps of determining that said flicker has occurred when said duration is greater than a first predetermined number and less than a second predetermined number, and determining that said flicker has not occurred when said duration is one of not greater than said first predetermined number and not less than said second predetermined number.

29. The process according to claim 28, further comprising the step of incrementing a glitch counter when it is determined that said flicker has occurred.

30. The process according to claim 29, further comprising the step of storing flicker information in a flicker event log when it is determined that said flicker has occurred.

31. The process according to claim 27, wherein said step of determining said duration of said flicker comprises counting a number of consecutive clock cycle occurrences of said flicker.

32. The process according to claim 31, further comprising the steps of determining that said flicker has occurred when said number of consecutive clock cycle occurrences greater than a first predetermined number and less than a second predetermined number, and determining that said flicker has not occurred when said number is one of not greater than said first predetermined number and not less than said second predetermined number.

33. The process according to claim 32, further comprising the step of incrementing a glitch counter when it is determined that said flicker has occurred.

34. The process according to claim 33, further comprising the step of storing flicker information in a flicker event log when it is determined that said flicker has occurred.