Fault detection system and associated method

• US 9,541,606 B2
• Filed: 12/17/2012
• Issued: 01/10/2017
• Est. Priority Date: 12/17/2012
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: General Electric Company
• Inventors: Neti, Prabhakar, Zhang, Pinjia
• Primary Examiner(s): PATEL, PARESH H
• Application Number:
  US13/716,969
• Publication Number:
  US 20140167810A1
• Time in Patent Office: 1,485 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis
• CPC Class Codes: G01R 31/34 Testing dynamo-electric machines
• CPC Class Codes: G01R 31/343 in operation

Abstract

A method implemented using a controller based device includes receiving a measured electrical signal from an electrical device of an electromechanical device and receiving a measured vibration signal from a mechanical device of the electromechanical device, coupled to the electrical device. The method further includes determining a first signal signature based on the measured electrical signal and determining a second signal signature based on the measured vibration signal. The method also includes determining a diagnostic parameter based on the first signal signature and the second signal signature and determining a fault in the mechanical device based on the diagnostic parameter.

Claims

1. A system, comprising:

a controller based device configured to;

receive measured electrical signals from an electrical device of an electromechanical device, wherein the electrical signals are representative of a measured current and a measured voltage of the electrical device;

receive a measured vibration signal from a mechanical device of the electromechanical device, coupled to the electrical device, wherein the mechanical device comprises a drive train;

determine a first signal signature based on the measured electrical signal by determining a spectrum of the electrical signal, wherein the spectrum may comprise a Fourier transform, a discrete Fourier transform, or a wavelet transform;

determine a second signal signature based on the measured vibration signal by performing a fast Fourier transform of the measured vibration signal;

determine a third signal signature based on the first signal signature and the second signal signature

determine a diagnostic parameter based on the first signal signature and the second signal signature, wherein the controller based device is further configured to determine the diagnostic parameter based on the third signal signature by computing at least one of an average value, a peak value, a median value of at least one of the first signal signature, the second signal signature and the third signal signature; and

determine a fault of the mechanical device based on the diagnostic parameter.

2. The system of claim 1, wherein the controller based device is configured to determine the second signal signature by determining a spectrum of the vibration signal.

3. The system of claim 1, wherein the controller based device is configured to determine the fault of the mechanical device by comparing the diagnostic parameter with a predefined threshold value.

5. The system of claim 1, wherein the controller based device is configured to add the first signal signature and the second signal signature to generate the third signal signature.

6. The system of claim 1, wherein the controller based device is configured to modulate a frequency of the first signal signature and a frequency of the second signal signature to generate the third signal signature.

7. The system of claim 3, wherein the controller based device is configured to determine a severity of the fault of the mechanical device by comparing the diagnostic parameter with two predefined threshold values.

9. The non-transitory computer readable medium of claim 1, wherein the program instructs the controller based device to determine the fault of the mechanical device by comparing the diagnostic parameter with a predefined threshold value.

12. The non-transitory computer readable medium of claim 9, wherein the program instructs the controller based device to determine a severity of the fault of the mechanical device by comparing the diagnostic parameter with two predefined threshold values.

13. The system of claim 1, wherein the first signal signature is a Fourier transform of the measured electrical signals and a frequency f_bearing:

of the first signal signature corresponds to a bearing fault a bearing of the drivetrain and is determined as

14. The system of claim 13, wherein the stator current frequency corresponding to the bearing fault is

f_s=|f_fundamental±

k·

f_bearing|,

wherein f_s is the stator current frequency, f_fundamental is the stator output frequency, k is a constant corresponding to different failure modes.

4. A non-transitory computer readable medium encoded with a program to instruct a controller based device to:

receive measured electrical signals from an electrical device of an electromechanical device, wherein the electrical signals are representative of a measured current and a measured voltage of the electrical device;

receive a measured vibration signal from a mechanical device of the electromechanical device, coupled to the electrical device, wherein the mechanical device comprises a drive train;

determine a first signal signature based on the measured electrical signal by determining a spectrum of the electrical signal, wherein the spectrum may comprise a Fourier transform, a discrete Fourier transform or a wavelet transform;

determine a second signal signature based on the measured vibration signal performing a fast Fourier transform of the measured vibration signal;

determine a third signal signature based on the first signal signature and the second signal signature

determine a diagnostic parameter based on the first signal signature and the second signal signature, wherein the controller based device is further configured to determine the diagnostic parameter based on the third signal signature by computing at least one of an average value, a peak value, a median value of at least one of the first signal signature, the second signal signature and the third signal signature; and

determine a fault of the mechanical device based on the diagnostic parameter.

8. The non-transitory computer readable medium of claim 4, wherein the program instructs the controller based device to determine the second signal signature by determining a spectrum of the vibration signal.

10. The non-transitory computer readable medium of claim 4, wherein program instructs the controller based device to add the first signal signature and the second signal signature to generate the third signal signature.

11. The non-transitory computer readable medium of claim 4, wherein the program instructs the controller based device to modulate a frequency of the first signal signature and a frequency of the second signal signature to generate the third signal signature.

15. The non-transitory computer readable medium of claim 4, wherein the first signal signature is a Fourier transform of the measured electrical signals and a frequency f_bearing:

of the first signal signature corresponds to a bearing fault a bearing of the drivetrain and is determined as

16. The non-transitory computer readable medium of claim 15, wherein the stator current frequency corresponding to the bearing fault is

f_s=|f_fundamental±

k·

f_bearing|,

wherein f_s is the stator current frequency, f_fundamental is the stator output frequency, k is a constant corresponding to different failure modes.