VIBRATION MONITORING

• US 20140116124A1
• Filed: 06/15/2012
• Published: 05/01/2014
• Est. Priority Date: 06/15/2011
• Status: Abandoned Application

• Current Assignee: Romax Technology Limited (Hexagon AB)
• Original Assignee: Romax Technology Limited (Hexagon AB)
• Inventors: Ma, Xiaoqin, Edwards, Daniel
• Application Number:
  US14/126,534
• Publication Number:
  US 20140116124A1
• Time in Patent Office: Days
• US Class Current: 73/112.01
• CPC Class Codes: F03D 17/00 Monitoring or testing of wind motors, e.g. diagnostics testing during commissioning of wind motors F03D13/30
• CPC Class Codes: F03D 80/50 Maintenance or repair
• CPC Class Codes: G01M 15/14 Testing gas-turbine engines or jet-propulsion engines
• CPC Class Codes: G05B 23/0232 based on qualitative trend analysis, e.g. system evolution
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A health index (124) can be determined from vibration signatures (108, 110, 112, 114) arising out of an analysis of vibration data (102, 104, 106) by using a combination of frequency analysis (e.g. crest factor, side-band factor) and analyses done in time domain. The health index (124) can thus be calculated by summing a product of one or more of these vibration signatures (108, 110, 112, 114) and a corresponding weighting factor (116, 118, 120, 122).

Claims

1-29. -29. (canceled)

30. The method for identifying a wind or water turbine or component thereof for maintenance, the method comprising the steps of:

analysing vibration data for the wind or water turbine or component thereof thereby providing one or more vibration signatures;

determining a health index from the one or more vibration signatures; and

comparing the health index with a maintenance threshold value

in which the step of determining a health index comprises the steps of;

providing corresponding weighting factors for the one or more vibration signatures; and

summing a product of the one or more vibration signatures and the corresponding weighting factor;

identifying a wind or water turbine or component thereof for maintenance having a health index above the maintenance threshold value.

31. The method according to claim 30, in which one or more vibration signatures comprise one or both of:

one or more vibration signals; and

one or more of frequency domain spectra.

32. The method according to claim 31, in which determining a health index comprises the preliminary step of:

extracting features from the one or more vibration signatures.

33. The method according to claim 30, in which the vibration signature is one or more of:

peak amplitude, RMS, kurtosis, crest factor, sideband factor, and energy present in the vibration data at a particular frequency.

34. The method according to claim 30, in which the health index is a single value based on one or more sets of vibration data.

35. The method according to claim 30, in which the corresponding weighting factors reflect the importance or strength of the vibration signature.

36. The method according to claim 30 in which maintenance includes any of:

down-rating the turbine;

investigating the wind turbine or component thereof; and

replacing or repairing the wind turbine or component thereof.

37. The method according to claim 30, additionally including a first step comprising:

processing the vibration data to remove noise interfering with the one or more vibration signatures.

38. The method according to claim 37, in which the step of processing the vibration data comprises the step of:

dividing the vibration data into ranges;

detecting locations of vibration signatures in each range;

calculating values of the vibration signatures;

combining the ranges.

39. The method according to claim 38, in which the step of detecting locations of vibration signatures comprises using a set of continuous wavelet functions.

40. The method according to claim 39, in which the step of detecting locations of vibration signatures comprises use of thresholds or limits to control the number of vibration signatures detected.

41. The method according to any of claim 30, additionally comprising the step of:

providing a rotational speed of a component associated with a vibration signature.

42. The method according to claim 41, in which the step of providing a rotational speed comprises the steps of:

providing expected vibration signatures;

providing for each expected vibration signature a ratio;

multiplying the ratio by a scaling factor;

creating a set of windows for each product of ratio and scaling factor;

adjusting the scaling factor to maximize a correlation between the set of windows and the vibration data;

wherein the scaling factor is a function of the rotational speed.

43. The method according to claim 42, in which the ratio is the ratio of a frequency of an expected vibration signature to a speed of a component of interest.

44. The method according to claim 43, in which the scaling factor is equal to the rotational speed.

45. A computer readable storage medium encoded with instructions that, when executed by a processor, perform:

analysing vibration data for the wind or water turbine or component thereof thereby providing one or more vibration signatures;

determining a health index from the one or more vibration signatures; and

comparing the health index with maintenance threshold values

in which the step of determining a health index comprises the steps of;

providing corresponding weighting factors for the one or more vibration signatures; and

summing a product of the one or more vibration signatures and the corresponding weighting factor;

identifying a wind or water turbine or component thereof for maintenance having a health index above the maintenance threshold value.

46. The method according to claim 45, in which one or more vibration signatures comprise one or both of:

one or more vibration signals; and

one or more of frequency domain spectra.

47. The method according to claim 46, in which determining a health index comprises the preliminary step of:

extracting features from the one or more vibration signatures.

48. The method according to claim 45, additionally comprising the step of:

providing a rotational speed of a component associated with a vibration signature.

49. The method according to claim 48, in which the step of providing a rotational speed comprises the steps of:

providing expected vibration signatures;

providing for each expected vibration signature a ratio;

multiplying the ratio by a scaling factor;

creating a set of windows for each product of ratio and scaling factor;

adjusting the scaling factor to maximize a correlation between the set of windows and the vibration data;

wherein the scaling factor is a function of the rotational speed.