REMOTE MONITORING OF TIGHTNESS OF STATOR WINDINGS

• US 20130162985A1
• Filed: 12/22/2011
• Published: 06/27/2013
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Berkcan, Ertugrul, Lape, Brock Matthew, Graf, John Frederick, Koste, Glen Peter, Hershey, John Erik
• Granted Patent: US 8,830,448 B2
• Time in Patent Office: Days
• US Class Current: 356/234
• CPC Class Codes: G01B 11/16 for measuring the deformation in a solid, e.g. optical strain gauge
• CPC Class Codes: G01L 5/0057 measuring forces due to spring-shaped elements
• CPC Class Codes: G01M 11/086 Details about the embedment of the optical fiber within the DUT

Abstract

A system for monitoring tightness of stator windings in an electric machine is provided. The system includes a light source for providing an optical power. The system also includes an optical separation sensor situated in a stator core and including an optical interface element for absorbing some of the optical power. Further, the system includes a power meter for measuring at least one intensity of the optical power after absorption by the optical interface element and a control subsystem for assessing the tightness of the stator windings.

Claims

1. A system for monitoring tightness of stator windings in an electric machine, the system comprising:

a light source for providing light at multiple wavelengths;

an optical separation sensor situated in a stator core, wherein the optical separation sensor comprises an optical interface element for differently absorbing the optical power at first and second wavelengths;

a power meter for measuring intensities of the optical power at the first and second wavelengths after absorption by the optical interface element; and

a control subsystem for using the measured intensities of optical power to assess the tightness of the stator windings.

2. The system of claim 1, wherein the optical separation sensor further comprises at least one optical fiber situated between wedge system components, wherein the at least one optical fiber comprises a core and a cladding surrounding the core, and wherein the optical interface element is situated at least partially within a section of the cladding for absorbing the optical power.

3. The system of claim 2, wherein the at least one optical fiber is embedded within one of the plurality of wedge system components.

4. The system of claim 2, wherein the wedge system components comprises ripple springs, wedges, plates, shims, and combinations thereof.

5. The system of claim 2, wherein the cladding comprises a portion with an indentation, and wherein the optical interface element comprises a dielectric component situated in the indentation.

6. The system of claim 5, wherein the dielectric component comprises a spherical shaped component configured for higher percentage absorption of the optical power at the first wavelength as compared to percentage absorption of the optical power at the second wavelength.

7. The system of claim 1, wherein the optical interface element comprises a wavelength selective material configured for higher percentage absorption of the optical power at the first wavelength as compared to percentage absorption of the optical power at the second wavelength.

8. The system of claim 7, wherein the wavelength selective material comprises a dielectric material doped with a chromatic pigment or dye.

9. The system of claim 1, wherein the control subsystem uses a ratio of the measured intensities of optical power to assess the tightness of the stator windings.

10. A ripple spring device comprising:

a ripple spring;

an optical separation sensor in contact with the ripple spring, wherein the optical separation sensor comprises an optical interface element for absorbing optical power from a light source.

11. The ripple spring device of claim 10 wherein the optical separation sensor is embedded into the ripple spring.

12. The ripple spring device of claim 10 wherein the optical separation sensor is held in place by adhesion or compression.

13. The ripple spring device of claim 10, wherein the optical separation sensor further comprises at least one optical fiber comprising a core and a cladding surrounding the core, and wherein the optical interface element is situated at least partially within a section of the cladding for absorbing at least one first wavelength of the optical power from the light source.

14. The ripple spring device of claim 13, wherein the cladding comprises a portion with an indentation and wherein the optical interface element comprises a dielectric component situated in the indentation.

15. The ripple spring device of claim 12, wherein the optical interface element comprises a wavelength selective material configured for higher percentage absorption of the optical power at the first wavelength as compared to percentage absorption of the optical power at a second wavelength.

16. A method for monitoring tightness of stator windings in an electrical machine, the method comprising:

directing an optical power from a light source to an optical separation sensor located between a plurality of wedge system components;

absorbing the optical power by an optical interface element of the optical separation sensor;

measuring at least one intensity of the optical power after absorption by the optical interface element; and

determining the tightness of the stator windings based on the at least one measured intensity of the optical power and calibration data.

17. The method of claim 16, wherein the optical separation sensor comprises at least one optical fiber situated between the plurality of wedge system components, wherein the at least one optical fiber comprises a core and a cladding surrounding the core, and wherein the optical interface element is situated at least partially within a section of the cladding for absorbing the optical power.

18. The method of claim 16, wherein the optical interface element is configured for higher percentage absorption of the optical power at a first wavelength as compared to percentage absorption of the optical power at a second wavelength.

19. The method of claim 18, wherein the ratio of the intensities at the first wavelength and the second wavelength are used to determine the tightness of the stator windings