Control system and a method for controlling a wind turbine
A control system for controlling operation of a wind turbine, a wind turbine having such a control system and a method for controlling a wind turbine are disclosed. The control system comprises a first sensor device and a second sensor device, each being arranged for measuring the same control parameter used for controlling operation of the wind turbine. The first sensor device has a first set of operating failure conditions, and the second sensor device has a second set of operating failure conditions. The first set of operating failure conditions comprises at least one operating failure condition which does not form part of the second set of operating failure conditions. The system further comprises a third sensor device for detecting an operating failure condition of the first sensor device and/or of the second sensor device. The control system is adapted to select between controlling operation of the wind turbine on the basis of control parameters measured by the first sensor device or on the basis of control parameters measured by the second sensor device, based on measurements performed by means of the third sensor device. Thereby a redundant system for measuring the control parameter is obtained, allowing reliable measurements of the control parameter, even under conditions where the first sensor device fails.
1. A control system for controlling operation of a wind turbine based on one or more control parameters, the control system comprising:
a first sensor device configured to measure a control parameter used for controlling operation of the wind turbine, wherein the first sensor device has a first set of operating failure conditions,
a second sensor device configured to measure the control parameter, wherein the second sensor device has a second set of operating failure conditions, and wherein the first set of operating failure conditions comprises at least one operating failure condition excluded from the second set of operating failure conditions, and
a third sensor device configured to detect an operating failure condition of at least one of the first sensor device and the second sensor device,
wherein the control system is configured to select between controlling operation of the wind turbine on the basis of control parameters measured by the first sensor device or on the basis of control parameters measured by the second sensor device, based on measurements performed by the third sensor device.
2. The control system of claim 1 , wherein the second set of operating failure conditions comprises at least one operating failure condition that does not form part of the first set of operating failure conditions.
3. The control system of claim 1 , wherein the first sensor device is configured to replace the second sensor device upon failure of the second sensor device.
4. The control system of claim 1 , wherein the second sensor device is configured to replace the first sensor device upon failure of the first sensor device.
5. The control system of claim 1 , wherein the first set of operating failure conditions and the second set of operating failure conditions are non-overlapping.
6. The control system of claim 1 , wherein the control system is configured to determine the validity of at least one of a first sensor signal and a second sensor signal.
7. The control system of claim 6 , wherein the control system is configured to generate a change control strategy signal upon at least one of determining that the first sensor signal and the second sensor signal are invalid, and detecting a failure condition of the first sensor device and of the second sensor device.
8. The control system of claim 1 , wherein the control parameter is wind speed.
9. The control system of claim 8 , wherein the first sensor device is a cup anemometer and the second sensor device is an ultrasonic wind sensor.
10. The control system of claim 1 , wherein the control parameter is wind direction.
11. The control system of claim 10 , wherein the first sensor device is a wind vane and the second sensor device is an ultrasonic wind sensor.
12. The control system of claim 1 , wherein the control parameter is a deflection of a load on at least one rotor blade of the wind turbine.
13. The control system of claim 12 , wherein the first sensor device is one or more electrical strain sensors arranged in or on one or more rotor blades, and the second sensor device is one or more optical fibres comprising fibre Bragg gratings arranged in or on one or more rotor blades.
14. The control system of claim 1 , wherein the control parameter is a pitch angle of a rotor blade of the wind turbine.
15. The control system of claim 14 , wherein the first sensor device is a pitch sensor and the second sensor device is a Global Positioning System (GPS) device arranged in or on a rotor blade.
16. The control system of claim 1 , wherein the control parameter is a yaw angle of the wind turbine.
17. The control system of claim 16 , wherein the first sensor device is a yaw counter and the second sensor device is a Global Positioning System (GPS) device arranged in or on a rotor blade.
18. The control system of claim 1 , wherein the control parameter is a rotational speed of a wind turbine rotor.
19. The control system of claim 18 , wherein the first sensor device is a rotation speed sensor and the second sensor device is a Global Positioning System (GPS) device arranged in or on a rotor blade.
20. The control system of claim 1 , wherein the third sensor device is a separate sensor.
21. The control system of claim 1 , wherein the third sensor device forms part of the first sensor device or the second sensor device.
22. The control system of claim 1 , wherein the third sensor device is configured to detect relative humidity of the ambient air.
23. A wind turbine comprising a tower construction, a nacelle accommodating at least a drive train, a set of rotor blades, and a control system for controlling operation of the wind turbine, wherein the control system comprises:
a first sensor device configured to measure a control parameter used for controlling operation of the wind turbine, wherein the first sensor device has a first set of operating failure conditions;
a second sensor device configured to measure the control parameter, wherein the second sensor device has a second set of operating failure conditions, and wherein the first set of operating failure conditions comprises at least one operating failure condition excluded from the second set of operating failure conditions; and
a third sensor device configured to detect an operating failure condition of at least one of the first sensor device and the second sensor device,
wherein the control system is configured to select between controlling operation of the wind turbine on the basis of control parameters measured by the first sensor device or on the basis of control parameters measured by the second sensor device, based on measurements performed by the third sensor device.
24. A method for controlling operation of a wind turbine, the method comprising:
measuring, from a first sensor signal via a first sensor device, a first value of a control parameter;
substantially simultaneously measuring, from a second sensor signal via a second sensor device, a second value of the control parameter;
measuring, via a third sensor device, a value of a failure condition parameter being indicative of an operating failure condition of at least one of the first sensor device and the second sensor device;
controlling operation of the wind turbine based on the first value and the second value of the control parameter, the value of the failure condition parameter, wherein the first sensor device has a first set of operating failure conditions and the second sensor device has a second set of operating failure conditions, and wherein the first set of operating failure conditions comprises at least one operating failure condition excluded from the second set of operating failure conditions.
25. The method of claim 24 , further comprising determining the validity of at least one of the first sensor signal and the second sensor signal, and wherein controlling operation of the wind turbine is further based on the result of determining the validity of at least one sensor signal.
26. The method of claim 25 , wherein controlling operation of the wind turbine comprises disregarding a sensor signal upon determining that the sensor signal is invalid.
27. The method of claim 25 , further comprising generating a change control strategy signal upon determining that the first sensor signal and the second sensor signal are invalid, thereby causing a change of operating control strategy for the wind turbine.
28. The method of claim 27 , further comprising controlling the wind turbine according to a load dependent control strategy in response to a generated change control strategy signal.
29. The method of claim 27 , wherein controlling operation of the wind turbine comprises primarily controlling operation of the wind turbine in accordance with a control strategy based on one or more measured control parameters including wind speed, and wherein controlling operation of the wind turbine further comprises controlling operation of the wind turbine in accordance with a control strategy based on one or more control parameters including a measured load when certain conditions are fulfilled.
30. The method of claim 24 , wherein measuring a value of a failure condition parameter comprises measuring relative humidity of the ambient air.