Energy meter with instrumentation systems and methods

• US 6,374,188 B1
• Filed: 11/30/1998
• Issued: 04/16/2002
• Est. Priority Date: 10/22/1996
• Status: Expired due to Term

• Current Assignee: Elster Electricity LLC (Honeywell International Inc.)
• Original Assignee: ABB Automation Inc (ABB Limited)
• Inventors: Hemminger, Rodney C., Holdsclaw, Scott T., Munday, Mark L., Hubbard, Vick A.
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): MILLER, CRAIG S
• Application Number:
  US09/201,439
• Time in Patent Office: 1,233 Days
• Field of Search: 702/57, 702/60-62, 702/64, 702/65, 702/79-81, 702/90, 702/189, 324/74, 324/76.11, 324/76.77, 324/86, 324/110, 324/500
• 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 for monitoring near-instantaneous system parameters of electrical energy having at least one phase provided to an energy meter via a service type comprises a memory for storing reference information reflective of different service types, a digital signal processor for measuring characteristics of the electrical energy, and a microcontroller for retrieving the reference information from the memory and determining the near-instantaneous system parameters responsive to the reference information for the service type and the measured characteristics. The characteristics are derived from phase voltage and phase current, and are measured for a predetermined amount of time, such as a number of line cycles.

Claims

1. A system for monitoring near-instantaneous system parameters of electrical energy having at least one phase provided to an energy meter via a service type, comprising:

storage means for storing reference information reflective of at least one service type;

means for measuring characteristics of said electrical energy; and

means for retrieving said reference information from said storage means and determining said near-instantaneous system parameters responsive to said reference information for the service type and said measured characteristics.

2. The system according to claim 1, wherein said characteristics are derived from phase voltage and phase current.

3. The system according to claim 1, wherein said characteristics are measured for a predetermined amount of time.

4. The system according to claim 3, wherein said predetermined amount of time is programmable.

5. The system according to claim 4, wherein said predetermined amount of time comprises a predetermined number of line cycles.

6. The system according to claim 1, further comprising memory means for recording said near-instantaneous system parameters.

7. The system according to claim 6, wherein said storage means comprises an EEPROM and said memory means comprises a RAM.

8. The system according to claim 7, wherein said EEPROM stores at least one threshold.

9. The system according to claim 8, wherein said threshold is programmable.

10. The system according to claim 9, further comprising an indicator and means for activating said indicator responsive to said threshold being surpassed by at least one of said near-instantaneous system parameters stored in said RAM.

11. The system according to claim 8, wherein said threshold comprises at least one of time, voltage, current, and power factor.

12. The system according to claim 8, wherein said threshold is responsive to the service type which provides electrical energy to said energy meter.

13. The system according to claim 8, wherein said threshold is independent of the service type which provides electrical energy to said energy meter.

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

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

16. The system according to claim 1, further comprising a display means for displaying said near-instantaneous system parameters.

17. The system according to claim 1, wherein said near-instantaneous system parameters comprise at least one of frequency, power, arithmetic kVAR, vectorial kVAR, arithmetic kVA, vectorial kVA, phase angle, current to voltage angle, arithmetic system power factor, vectorial system power factor, phase voltage, phase current, phase power factor, phase current to phase voltage angle, phase kW, phase kVA, phase kVAR, total harmonic distortion, second harmonic current distortion, general Nth voltage harmonic magnitude, and general Nth current harmonic magnitude.

18. The system according to claim 1, wherein said near-instantaneous system parameters are selectable via one of optical communications and electronically from an external source.

19. The system according to claim 1, wherein said means for determining said near-instantaneous system parameters comprises programmable conversion routines.

20. The system according to claim 1, wherein the service type is one of single phase and multiphase, and said near-instantaneous system parameters are determined for each phase when the service is multiphase.

21. The system according to claim 1, further comprising means for activating said means for measuring characteristics of said electrical energy.

22. The system according to claim 21, wherein said means for activating are user-activated.

23. The system according to claim 21, wherein said means for activating activates said means for measuring responsive to a priority scheme.

24. The system according to claim 1, further comprising means for linking at least two of said measured characteristics, said near-instantaneous system parameters being determined responsive to said linked measured characteristics.

25. An electronic processor-implemented process for monitoring near-instantaneous system parameters of electrical energy provided to an energy meter via a service type, comprising the steps of:

storing reference information in a memory reflective of at least one service type;

measuring characteristics of said electrical energy provided to the energy meter; and

retrieving said reference information from said memory and determining said near-instantaneous system parameters responsive to said reference information for the service type and said measured characteristics.

26. The process according to claim 25, wherein said characteristics are derived from phase voltage and phase current.

27. The process according to claim 25, wherein said characteristics are measured for a predetermined amount of time.

28. The process according to claim 27, wherein said predetermined amount of time is programmable.

29. The process according to claim 28, wherein said predetermined amount of time comprises a predetermined number of line cycles.

30. The process according to claim 25, further comprising the step of recording said near-instantaneous system parameters in a second memory.

31. The process according to claim 30, wherein said memory comprises an EEPROM and said second memory comprises a RAM.

32. The process according to claim 31, wherein said EEPROM stores at least one threshold.

33. The process according to claim 32, wherein said threshold is programmable.

34. The process according to claim 33, further comprising the step of activating an indicator responsive to said threshold being surpassed by at least one of said near-instantaneous system parameters stored in said RAM.

35. The process according to claim 32, wherein said threshold comprises at least one of time, voltage, current, and power factor.

36. The process according to claim 32, wherein said threshold is responsive to the service type which provides electrical energy to said energy meter.

37. The process according to claim 32, wherein said threshold is independent of the service type which provides electrical energy to said energy meter.

38. The process according to claim 25, further comprising the step of displaying said near-instantaneous system parameters.

39. The process according to claim 25, wherein said near-instantaneous system parameters comprise at least one of frequency, power, arithmetic kVAR, vectorial kVAR, arithmetic kVA, vectorial kVA, phase angle, current to voltage angle, arithmetic system power factor, vectorial system power factor, phase voltage, phase current, phase power factor, phase current to phase voltage angle, phase kW, phase kVA, phase kVAR, total harmonic distortion, second harmonic voltage distortion, general Nth voltage harmonic magnitude, and general Nth current harmonic magnitude.

40. The process according to claim 25, further comprising the step of selecting said near-instantaneous system parameters via one of optical communications and electronically from an external source.

41. The process according to claim 25, wherein said step of determining said near-instantaneous system parameters comprises converting said reference information and said measured characteristics using programmable conversion routines.

42. The process according to claim 25, wherein the service type is one of single phase and multiphase, and said near-instantaneous system parameters are determined for each phase when the service is multiphase.

43. The process according to claim 25, further comprising the step of activating said step of measuring characteristics of said electrical energy.

44. The process according to claim 43, wherein said step of activating is user-activated.

45. The process according to claim 43, wherein said step of activating activates said step of measuring responsive to a priority scheme.

46. The process according to claim 25, further comprising the step of linking at least two of said measured characteristics, said near-instantaneous system parameters being determined responsive to said linked measured characteristics.

47. A system for monitoring near-instantaneous system parameters of electrical energy having at least one phase provided to an energy meter via a service type, comprising:

a first memory device that stores reference information reflective of at least one service type;

a digital signal processor (DSP) that measures characteristics of said electrical energy; and

a microcontroller that retrieves said reference information from said first memory device and determines said near-instantaneous system parameters responsive to said reference information for the service type and said measured characteristics.

48. The system according to claim 47, wherein said characteristics are derived from phase voltage and phase current.

49. The system according to claim 47, wherein said characteristics are measured for a predetermined amount of time.

50. The system according to claim 49, wherein said predetermined amount of time is programmable.

51. The system according to claim 50, wherein said predetermined amount of time comprises a predetermined number of line cycles.

52. The system according to claim 47, further comprising a second memory device for recording said near-instantaneous system parameters.

53. The system according to claim 52, wherein said first memory device comprises an EEPROM and said second memory device comprises a RAM.

54. The system according to claim 53, wherein said EEPROM stores at least one threshold.

55. The system according to claim 54, wherein said threshold is programmable.

56. The system according to claim 55, further comprising an indicator and means for activating said indicator responsive to said threshold being surpassed by at least one of said near- instantaneous system parameters stored in said RAM.

57. The system according to claim 54, wherein said threshold comprises at least one of time, voltage, current, and power factor.

58. The system according to claim 54, wherein said threshold is responsive to the service type which provides electrical energy to said energy meter.

59. The system according to claim 54, wherein said threshold is independent of the service type which provides electrical energy to said energy meter.

60. The system according to claim 47, further comprising a display that displays said near-instantaneous system parameters.

61. The system according to claim 47, wherein said near-instantaneous system parameters comprise at least one fo the frequency, power, arithmetic kVAR, vectorial kVAR, arithmetic kVA, vectorial kVA, phase angle, current to voltage angle, arithmetic system power factor, vectorial system power factor, phase voltage, phase current, phase power factor, phase current to phase voltage angle, phase kW, phase kVA, phase kVAR, total harmonic distortion, second harmonic current distortion, general Nth voltage harmonic magnitude, and general Nth current harmonic magnitude.

62. The system according to claim 47, wherein said near-instantaneous system parameters are selectable via one of optical communications and eletronically from an external source.

63. The system according to claim 47, wherein said microcontroller comprises programmable conversion routines.

64. The system according to claim 47, wherein the service type is one of single phase and multiphase, and said near-instantaneous system parameters are determined for each phase when the service is multiphase.

65. The system according to claim 47, further comprising a measurement requester that activates said DSP.

66. The system according to claim 65, wherein said measurement requester is user-activated.

67. The system according to claim 65, wherein said measurement requester activates said DSP responsive to a priority scheme.

68. The system according to claim 47, further comprising a measurement engine that links at least two of said measured characteristics, said near-instantaneous system parameters being determined responsive to said linked measured characteristics.