Method and system of monitoring electrical brushes

1. A method, comprising:

continuously measuring at least one parameter associated with an electrical brush;

determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush, wherein continuously measuring the at least one parameter associated with the electrical brush comprises continuously measuring a length value for the electrical brush, wherein continuously measuring the length value for the electrical brush comprises measuring a travel time of ultrasonic waves within the electrical brush and determining the length value for the electrical brush from the measured travel time of the ultrasonic waves, and wherein continuously measuring the at least one parameter associated with the electrical brush further comprises measuring a spring pressure on the electrical brush using a wave velocity of the ultrasonic waves within the electrical brush.

2. The method of claim 1 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining when to replace the electrical brush.

3. The method of claim 1 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining whether to replace the electrical brush based at least in part on the length value for the electrical brush.

4. The method of claim 1 , wherein continuously measuring the length value for the electrical brush comprises using one or more of a linear actuator, proximity sensor, position encoder, or a rotational position sensor placed on a pivot point of a brush holder associated with the electrical brush to continuously measure the length value of the electrical brush.

5. The method of claim 4 , wherein an output of the one or more linear actuator, proximity sensor, position encoder, or a rotational position sensor placed on a pivot point of a brush holder associated with the electrical brush is transmitted to a remote monitoring station over a network.

6. The method of claim 5 , wherein the network comprises a supervisory control and data acquisition (SCADA) network.

7. The method of claim 1 , wherein continuously measuring the length value for the electrical brush comprises measuring a travel time of ultrasonic waves within the electrical brush and determining the length value for the electrical brush from the measured travel time of the ultrasonic waves comprises using one or more ultrasonic sensors mounted to the electrical brush to measure the travel time of ultrasonic waves within the electrical brush.

8. The method of claim 7 , wherein an output from the one or more ultrasonic sensors mounted to the electrical brush is transmitted to a remote monitoring station over a network.

9. The method of claim 8 , wherein the network comprises a supervisory control and data acquisition (SCADA) network.

10. The method of claim 1 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining when to replace the electrical brush based at least in part on the brush length and the spring pressure.

11. A system, comprised of:

an electrical brush; and

an electrical brush parameter measurement device, wherein the electrical brush parameter measurement device continuously measures at least one parameter associated with the electrical brush and said at least one continuously measured parameter associated with the electrical brush is used to determine maintenance for the electrical brush, wherein the electrical brush parameter measurement device continuously measuring the at least one parameter associated with the electrical brush comprises the electrical brush parameter measurement device continuously measuring a length value for the electrical brush, wherein the electrical brush parameter measurement device comprises using one or more ultrasonic sensors mounted to the electrical brush to measure the travel time of ultrasonic waves within the electrical brush continuously measuring the length value for the electrical brush comprises determining the length value for the electrical brush from the measured travel time of the ultrasonic waves, and wherein continuously measuring the at least one parameter associated with the electrical brush further comprises measuring a spring pressure on the electrical brush using a wave velocity of the ultrasonic waves within the electrical brush.

12. The system of claim 11 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining when to replace the electrical brush.

13. The system of claim 11 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining whether to replace the electrical brush based at least in part on the length value for the electrical brush.

14. The system of claim 11 , wherein the electrical brush parameter measurement device comprises one or more of a linear actuator, proximity sensor, position encoder, or a rotational position sensor placed on a pivot point of a brush holder associated with the electrical brush to continuously measure the length value of the electrical brush.

15. The system of claim 14 , wherein an output of the one or more linear actuator, proximity sensor, position encoder, or a rotational position sensor placed on a pivot point of a brush holder associated with the electrical brush is transmitted to a remote monitoring station over a network.

16. The system of claim 15 , wherein the network comprises a supervisory control and data acquisition (SCADA) network.

17. The system of claim 11 , wherein an output from the one or more ultrasonic sensors mounted to the electrical brush is transmitted to a remote monitoring station over a network.

18. The system of claim 17 , wherein the network comprises a supervisory control and data acquisition (SCADA) network.

19. The system of claim 11 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining when to replace the electrical brush based at least in part on the brush length and the spring pressure.

20. A wind turbine generator comprised of:

a rotor;

a slip ring mounted on the rotor;

an electrical brush in contact with the slip ring; and

an electrical brush parameter measurement device, wherein the electrical brush parameter measurement device continuously measures at least one parameter associated with the electrical brush and said at least one continuously measured parameter associated with the electrical brush is used to determine maintenance for the electrical brush, wherein the electrical brush parameter measurement device continuously measuring the at least one parameter associated with the electrical brush comprises the electrical brush parameter measurement device continuously measuring a length value for the electrical brush, wherein the electrical brush parameter measurement device comprises using one or more ultrasonic sensors mounted to the electrical brush to measure the travel time of ultrasonic waves within the electrical brush continuously measuring the length value for the electrical brush comprises determining the length value for the electrical brush from the measured travel time of the ultrasonic waves, and wherein continuously measuring the at least one parameter associated with the electrical brush further comprises measuring a spring pressure on the electrical brush using a wave velocity of the ultrasonic waves within the electrical brush.

21. The wind turbine generator of claim 20 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining when to replace the electrical brush.

22. The wind turbine generator of claim 20 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining whether to replace the electrical brush based at least in part on the length value for the electrical brush.

23. The wind turbine generator of claim 20 , wherein the electrical brush parameter measurement device comprises one or more of a linear actuator, proximity sensor, position encoder, or a rotational position sensor placed on a pivot point of a brush holder associated with the electrical brush to continuously measure the length value of the electrical brush.

24. The wind turbine generator of claim 23 , wherein an output of the one or more linear actuator, proximity sensor, position encoder, or a rotational position sensor placed on a pivot point of a brush holder associated with the electrical brush is transmitted to a remote monitoring station over a network.

25. The wind turbine generator of claim 24 , wherein the network comprises a supervisory control and data acquisition (SCADA) network.

26. The wind turbine generator of claim 20 , wherein an output from the one or more ultrasonic sensors mounted to the electrical brush is transmitted to a remote monitoring station over a network.

27. The wind turbine generator of claim 26 , wherein the network comprises a supervisory control and data acquisition (SCADA) network.

28. The wind turbine generator of claim 20 , wherein determining, using the at least one continuously measured parameter associated with the electrical brush, maintenance for the electrical brush comprises determining when to replace the electrical brush based at least in part on the brush length and the spring pressure.