System for Electrical Apparatus Testing

• US 20100060289A1
• Filed: 09/05/2008
• Published: 03/11/2010
• Est. Priority Date: 09/05/2008
• Status: Abandoned Application

• Current Assignee: SKF USA Incorporated (SKF)
• Original Assignee: SKF USA Incorporated (SKF)
• Inventors: Lee, Sang Bin, Wiedenbrug, Ernesto
• Application Number:
  US12/205,816
• Publication Number:
  US 20100060289A1
• Time in Patent Office: Days
• US Class Current: 324/511
• CPC Class Codes: G01R 31/343 in operation
• CPC Class Codes: G01R 31/66 Testing of connections, e.g. of plugs or non-disconnectable joints testing for incorrect line connections G01R31/55

Abstract

An easily implemented method of diagnosing both supply path, upstream, and load path, downstream, anomalies such as impedance events in machine or motor circuitry is accomplished by analyzing the across-the-line startup current and voltage time waveforms. No line of sight limitations exist and high accuracy exists. The techniques can be automated estimating poor contact resistance based on the voltage and current variation under a load change condition perhaps such as startup and/or shutdown of the load. Both, upstream and downstream problems from the point of voltage measurement can be monitored analyzing a load change condition. Additionally, downstream problems can be identified by using negative sequence current under steady state operation of the load.

Claims

1. A method of quantifying electric machine circuitry anomalies comprising the steps of:

accessing at least a portion of an electric machine power circuit characterizeable as having a supply path and a load path;

load change condition sensing at least one electrical effect at a sense location between said supply path and said load path;

measuring a supply path voltage effect at said sense location; and

ascertaining the existence of a supply path anomaly condition from said step of measuring a supply path voltage effect at said sense location.

12. A method of quantifying electric machine circuitry anomalies as described in claim 1 or 2 wherein said step of quantitatively ascertaining the existence of a supply path anomaly condition comprises the step of ascertaining an electrical magnitude variation.

14. A method of quantifying electric machine circuitry anomalies as described in claim 1 or 2 wherein said step of quantitatively ascertaining the existence of a supply path anomaly condition comprises the step of utilizing historical data for said electric machine circuitry.

2. A method of quantifying electric machine circuitry anomalies comprising the steps of:

accessing at least a portion of an electric machine power circuit characterizeable as having a supply path and a load path;

sensing at least one electrical effect at a sense location between said supply path and said load path;

measuring a supply path voltage effect at said sense location;

measuring a supply path current effect at said sense location;

quantitatively ascertaining the existence of a supply path anomaly condition from said steps of measuring a supply path voltage effect and measuring a supply path current effect at said sense location.

3. A method of quantifying electric machine circuitry anomalies as described in claim 2 or 3 wherein said step of sensing at least one electrical effect comprises the step of sensing said at least one electrical effect at only said sense location.

13. A method of quantifying electric machine circuitry anomalies as described in claim 2 wherein said steps of quantitatively ascertaining the existence of a supply path anomaly condition comprises the step of ascertaining an electrical angle variation.

21. A method of quantifying electric machine circuitry anomalies as described in claim 2 wherein said step of quantitatively ascertaining the existence of a supply path anomaly condition comprises the step of sensing an asymmetry condition for said electrical machine circuitry.

26. A method of quantifying electric machine circuitry anomalies as described in claim 2 wherein said step of quantitatively ascertaining the existence of a supply path anomaly condition comprises the step of conducting a low resistance phase comparison for said electric machine circuitry.

106. A method of evaluating electric machine circuitry as described in claim 2, 30, or 50 wherein said step of ascertaining comprises the step of estimating an individual phase condition within said electric machine circuitry.

107. A method of evaluating electric machine circuitry as described in claim 106 wherein said step of estimating an individual phase condition within said electric machine circuitry comprises the step of estimating a supply path power circuitry condition within said electric machine circuitry.

108. A method of evaluating electric machine circuitry as described in claim 107 wherein said step of estimating a supply path power circuitry condition within said electric machine circuitry comprises the step of estimating a purely resistive supply path anomaly.

109. A method of evaluating electric machine circuitry as described in claim 107 wherein said step of estimating a supply path power circuitry condition comprises the steps of:

measuring a supply path voltage variation; and

measuring a supply path current variation.

110. A method of evaluating electric machine circuitry as described in claim 106 wherein said step of estimating an individual phase condition within said electric machine circuitry comprises the step of estimating a load path power circuitry condition within said electric machine circuitry.

111. A method of evaluating electric machine circuitry as described in claim 110 wherein said step of estimating a load path power circuitry condition within said electric machine circuitry comprises the step of estimating a purely resistive load path anomaly.

112. A method of evaluating electric machine circuitry as described in claim 2, 30, or 50 and further comprising the step of ascertaining if a load path anomaly condition exists from said step of determining at least one electrical parameter at said sense location.

113. A method of evaluating electric machine circuitry as described in claim 112 and further comprising the step of experiencing a load change condition within said load path, and wherein said step of sensing comprises the step of load change condition sensing at least one electrical effect.

114. A method of evaluating electric machine circuitry as described in claim 112 wherein said step of ascertaining if a load path anomaly condition exists comprises the step of sensing at least one load path electrical effect at said sense location between said supply path and said load path.

116. A method of evaluating electric machine circuitry as described in claim 114 wherein said step of sensing at least one load path electrical effect comprises the step of sensing a load path current angle effect.

117. A method of evaluating electric machine circuitry as described in claim 116 wherein said step of sensing a load path current angle effect comprises the step of sensing a negative sequence current.

121. A method of evaluating electric machine circuitry as described in claim 113 wherein said step of ascertaining comprises the step of conducting a pre- and post-load change condition comparison.

4. A method of quantifying electric machine circuitry anomalies as described in 2 wherein said step of sensing at least one electrical effect comprises the step of load change condition sensing at least one electrical effect.

5-6. -6. (canceled)

7. A method of quantifying electric machine circuitry anomalies as described in 2 wherein said step of sensing at least one electrical effect comprises the step of operationally active circuitry sensing at least one electrical effect while said machine circuitry is in an operative configuration.

8-11. -11. (canceled)

15-20. -20. (canceled)

22-25. -25. (canceled)

27-29. -29. (canceled)

30. A method of testing electric machine circuitry comprising the steps of:

accessing at least a portion of an electric machine power circuit characterizeable as having a supply path and a load path;

experiencing a load change condition within said load path;

load change condition sensing at least one electrical effect from said load change condition at a sense location between said supply path and said load path;

determining at least one electrical parameter at said sense location; and

ascertaining if a supply path anomaly condition exists from said step of determining at least one electrical parameter at said sense location.

31. A method of testing electric machine circuitry as described in claim 30 wherein said step of load change condition sensing at least one electrical effect comprises the step of load change condition sensing said at least one electrical effect at only said sense location.

32. A method of testing electric machine circuitry as described in claim 31 wherein said step of load change condition sensing at least one electrical effect comprises the step of operationally active circuitry load change condition sensing at least one electrical effect while said machine circuitry is in an operative configuration.

33. A method of testing electric machine circuitry as described in claim 30 and further comprising the step of assuring a load path steady state operational condition while accomplishing said step of load change condition sensing.

34. A method of testing electric machine circuitry as described in claim 31 wherein said step of experiencing a load change condition comprises the step of switching an operational condition load change condition.

35. A method of testing electric machine circuitry as described in claim 30 wherein said step of experiencing a load change condition comprises the step of experiencing a substantial load change condition.

36. A method of testing electric machine circuitry as described in claim 35 wherein said step of experiencing a substantial load change condition is selected from a group consisting of:

experiencing a greater than rated current load change condition; and

experiencing a greater than four times rated current load change condition.

37. A method of testing electric machine circuitry as described in claim 30 wherein said step of experiencing a load change condition comprises the step of experiencing a normative operational load change condition.

39. A method of testing electric machine circuitry as described in claim 37 wherein said step of experiencing a normative operational load change condition comprises a step selected from a group consisting of:

experiencing a machine start up condition;

experiencing a machine shut down condition; and

experiencing a machine power factor change condition.

45. A method of testing electric machine circuitry as described in claim 30 or wherein said step of ascertaining if a supply path anomaly condition exists comprises the step of conducting a pre- and post-load change condition comparison.

49. A method of testing electric machine circuitry as described in claim 45 wherein said step of conducting a pre- and post-load change condition comparison is selected from a group consisting of:

conducting a pre- and post-load change condition voltage effect comparison;

conducting a pre- and post-load change condition current effect comparison;

conducting a pre- and post-load change condition magnitude effect comparison;

conducting a pre- and post-load change condition angle effect comparison;

conducting a pre- and post-load change condition voltage magnitude effect comparison;

conducting a pre- and post-load change condition voltage angle effect comparison;

conducting a pre- and post-load change condition current magnitude effect comparison;

conducting a pre- and post-load change condition current angle effect comparison; and

conducting a pre- and post-load change condition comparison that is any combination or permutation of the above.

38. (canceled)

40-44. -44. (canceled)

46-48. -48. (canceled)

50. A method of identifying an incipient fault electric machine circuitry anomaly comprising the steps of:

accessing at least a portion of an electric machine power circuit characterizeable as having a supply path and a load path;

sensing at least one electrical effect at a sense location between said supply path and said load path;

determining at least one electrical parameter at said sense location; and

ascertaining if an incipient fault supply path anomaly condition exists from said step of determining at least one electrical parameter at said sense location.

51. A method of identifying an incipient fault electric machine circuitry anomaly as described in claim 50 wherein said step of sensing at least one electrical effect comprises the step of sensing said at least one electrical effect at only said sense location.

53. A method of identifying an incipient fault electric machine circuitry anomaly as described in claim 50 wherein said step of sensing at least one electrical effect comprises the step of operationally active circuitry sensing at least one electrical effect while said machine circuitry is in an operative configuration.

54. A method of identifying an incipient fault electric machine circuitry anomaly as described in claim 53 wherein said step of sensing at least one electrical effect comprises the step of load change condition sensing at least one electrical effect.

57. A method of identifying an incipient fault electric machine circuitry anomaly as described in claim 53 wherein said step of ascertaining if an incipient fault supply path anomaly condition exists comprises the step of interphase comparing electrical machine circuitry effects.

60. A method of identifying an incipient fault electric machine circuitry anomaly as described in claim 57 wherein said step of ascertaining if an incipient fault supply path anomaly condition exists comprises the step of conducting a low resistance phase comparison for said electric machine circuitry.

62. A method of identifying an incipient fault electric machine circuitry anomaly as described in claim 53 wherein said step of ascertaining if an incipient fault supply path anomaly condition exists comprises the step of substantially continuously ascertaining if an incipient fault supply path anomaly condition exists during operating conditions for said electric machine circuitry.

52. (canceled)

55-56. -56. (canceled)

58-59. -59. (canceled)

61. (canceled)

63-105. -105. (canceled)

115. (canceled)

118-120. -120. (canceled)

122-244. -244. (canceled)