RELATIVE ROTOR BLADE MISALIGNMENT

Abstract

Disclosed is a method of monitoring relative blade pitch angle alignment of a set of at least two rotor blades in a rotary device. The rotary device may be a wind turbine generator. Also disclosed are operational schemes based on the observed relative blade pitch angle alignments.

Claims

1. A method of monitoring relative blade pitch angle alignment of a set of at least two rotor blades in a rotary device; the method comprising acts of: collecting one or more dataset from a set of one or more blade sensors of the at least two rotor blades; calibrating one blade sensor from one set of blade sensors against at least one blade sensor from another set of blade sensors; calculating a calibration correction factor for the blade sensors; applying the calibration correction factor to each respective data sets; and classifying the relative blade pitch angle alignment between the pitch angle of at least one combination of rotor blades in the set of least two rotor blades.

2. The method of claim 1, wherein the acts of collecting and calibrating are performed with the rotary device in a static state, and wherein the act applying the static calibration correction factor is performed on relative dynamic blade pitch misalignment from the rotary device in a static state position compared to when the rotary device is dynamic state.

3. The method of claim 1, wherein the act of collecting datasets is performed as timestamped data, and wherein the method further includes an act of synchronizing the collected datasets according to timestamps.

4. The method of claim 1, wherein the act of calibrating is performed against at least one other sensor from the rotary device.

5. The method of claim 1, wherein the act of collecting is performed with blade sensors arranged substantially identical on the respective rotor blades.

6. The method of claim 1, wherein acts are performed on the rotary device including three rotor blades, and wherein the act of collecting is performed as: collecting a A-dataset during a time period where the rotary device is in the static-state with the rotor blade A in a predefined position P; collecting a B-dataset where the rotary device is in the static-state with the rotor blade B in the predefined position P; and collecting a C-dataset where the rotary device is in the static-state with the rotor blade C in a predefined position P.

7. The method of claim 6, wherein the act of calibrating is performed only based on collected data sets A-, B-, and C-datasets.

8. The method of claim 1, wherein the act of classifying is performed in different states of rotary device operational states including at least the states of: the static-state; or the dynamic-stat.

9. The method of claim 1, wherein the act of classifying is performed at various rotational speeds of the rotary device.

10. The method according to claim 1, wherein the rotary device is a rotor of a wind turbine generator and the rotor blades are blades of the wind turbine generator.

11. The method according to claim 10, further including acts of monitoring and classifying aerodynamic efficiency and to classify into relative blade aerodynamic efficiencies between at least one combination in the set of at least two rotor blades.

12. A method of operating a rotary device including the acts of: providing the rotary device; monitoring relative blade pitch angle alignment of the rotary device according to claim 1; and operating the rotary device as a function of the classified relative pitch angle alignment.

13. The method of claim 12, wherein the rotary device is a wind turbine generator and wherein the act of operating the rotary device is performed in a corrected mode of operation if the monitored relative blade pitch angle alignment is at or above a threshold value.

14. The method of claim 13, wherein the act of monitoring and classifying further include acts of monitoring and classifying relative differences in blade aerodynamic efficiencies between at least one combination in the set of at least two rotor blades; and wherein the act of operating further includes operating the rotary device as a function of the classified relative aerodynamic efficiency.

15. A blade pitch angle alignment monitoring system comprising: a set of one or more blade sensors; and computational means configured to perform the acts of claim 1.

Description

DESCRIPTION OF THE DRAWING

[0199] Embodiments of the invention will be described in the figures, whereon:

[0200] FIG. 1 illustrates a method of monitoring relative pitch angle alignment;

[0201] FIG. 2 illustrates an additional act of calibrating;

[0202] FIG. 3 illustrates a method of operating a rotary device involving relative pitch angle alignment;

[0203] FIG. 4 illustrates definitions of relative pitch angles of a rotary device;

[0204] FIG. 5 illustrates a rotary device; in this case a wind turbine generator;

[0205] FIG. 6 illustrates a sensory arrangement on blades of a rotary device;

[0206] FIG. 7 illustrates further aspects of sensory arrangement on a rotary device;

[0207] FIG. 8 illustrates multiple sensor node arrangement options and illustrates arrangements of sensors on blades;

[0208] FIG. 9 illustrates a rotary device with relative blade pitch angle alignment in interaction with a remote/cloud based operating/monitoring system;

[0209] FIG. 10 illustrates aspects of aerodynamic efficiency in comparison to FIG. 11,

[0210] FIG. 11 illustrates a aspects of aerodynamic efficiency as a function of swept area,

[0211] FIG. 12 illustrates sector based classification of aerodynamic efficiency,

[0212] FIG. 13 illustrates an example of data analysis based on a “Roll”-type method;

[0213] FIG. 14 illustrates an example of data analysis based on a “Fitting Ellipse” type of method; and

[0214] FIG. 15 illustrates aspects of aerodynamic blade efficiency with and without relative blade pitch angle alignment.

DETAILED DESCRIPTION OF THE INVENTION

[0215]

TABLE-US-00003 Item No Rotary device 10 Wind Turbine Generator (WTG) 12 Rotor 14 Swept area 16 Rotor sector 18 Set of rotor blades 20 Rotor blade/blade 22 Dataset 30 Timestamped data 32 Timestamp 34 Set of blade sensors 40 Blade sensor 42 Pitch alignment monitoring system 50 Computational means 60 Controller 62 Cloud/Connection 70 Operator System 74 Mobile device 76 Client Server 77 Database/storage 80 Method of monitoring relative blade 100 pitch angle alignment Relative blade pitch angle alignment 102 Pitch angle 104 Combination of rotor blades 106 Collecting 110 Calibrating 120 Calculating 130 Applying 140 Classifying 150 Relative blade aerodynamic efficiencies 154 Correction factor 132 Synchronizing 160 Method of operating a rotary device 200 Providing 210 Operating 220 Corrected mode of operating 225

[0216] FIG. 1 illustrates a method 100 of monitoring relative pitch angle alignment 102.

[0217] The method 100 of monitoring relative blade pitch angle alignment 102 of a set of 20 at least two rotor blades 22 in a rotary device 10 will be illustrated or exemplified in FIGS. 4 to 6.

[0218] The method 100 comprising acts involving:

[0219] An act of collecting 110 one or more dataset 30 from a set 40 of one or more blade sensors 42 configured to sense respective least two rotor blades 22.

[0220] There is an act of calibrating 120 one blade sensor 42 from one set 40A of blade sensors 42 against at least one blade sensor 42 from another set 40B of blade sensors 42.

[0221] There is an act of calculating 130 a calibration correction factor 132 for the blade sensors 42.

[0222] There is an act of applying 140 the calibration correction factor 132 to each respective data set 30.

[0223] There is an act of classifying 150 the relative blade pitch angle alignment 102 between the pitch angles 104 of at least one combination of rotor blades 106 in the set of least two rotor blades 22.

[0224] FIG. 2 illustrates an additional act of synchronising 160. The method 100 again relates to examples and implantations shown in FIGS. 4-6.

[0225] In view of the described method 100 illustrated in FIG. 1 the act of collecting datasets 110 is performed as timestamped data 32 and the method further comprising an act of synchronizing 160 the collected datasets 30 according to timestamps 34.

[0226] Synchronizing 160 may be performed by computational means 60. Synchronization 160 may be performed at sensor node 42 level. A timestamp 34 may be obtained from a local clock or from a global clock and applied to sampled data to generate timestamped data 32.

[0227] There is an act of classifying 150 the relative blade pitch angle alignment 102 between the pitch angles 104 of at least one combination of rotor blades 106 in the set of least two rotor blades 22.

[0228] FIG. 3 illustrates a method 200 of operating a rotary device 10 involving relative pitch angle alignment 102.

[0229] The method 200 of operating a rotary device 200 comprises the acts illustrated.

[0230] There is an act of providing 210 the rotary device 10.

[0231] There is an act of monitoring 100 relative blade pitch angle alignment 102 of the rotary device 10.

[0232] There is an act of operating 220 rotary device 10 as a function of the classified relative pitch angle alignment 102.

[0233] FIG. 4 illustrates definitions of relative pitch angles of a rotary device 10.

[0234] The rotary device 10 comprises a set of rotor blades 20. The set of rotor blades 20 comprises two rotor blades 22.

[0235] The rotary device 10 with four positions of the rotor blades 22 are disclosed in FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D.

[0236] Projections 10P of the rotary device 10 are shown for each of the four positions.

[0237] Each rotor blade 22 is positioned at a pitch angle (ϕ.sub.i and ϕ.sub.j) 104. The pitch angles (ϕ.sub.i and ϕ.sub.j) 104 are measured using a set of blade sensors 40 (not shown) on each rotor blade 22. The set of blade sensors 40 comprises on or more blade sensors 42.

[0238] A relative pitch angle alignment 102 is defined as a difference (Δϕ.sub.ij) between the pitch angles (ϕ.sub.i and ϕ.sub.j) 104 of the two rotor blades 22:

Δϕ.sub.ij=ϕ.sub.i−ϕ.sub.j

[0239] The relative pitch angle alignment (Δϕ.sub.ij) 102 is equal to zero if the pitch angles (ϕ.sub.i and ϕ.sub.j) 104 of the two rotor blades 22 are equal.

[0240] The relative pitch angle alignment (Δϕ.sub.ij) 102 is different from zero if the pitch angles (ϕ.sub.i and ϕ.sub.j) 104 of the two rotor blades 22 are different from one another.

[0241] In FIG. 4A the pitch angles (ϕ.sub.i and ϕ.sub.j) 104 are equal to zero and thus the relative pitch angle alignment (Δϕ.sub.ij) 102 is equal to zero.

[0242] In FIG. 4B the pitch angles (ϕ.sub.i and ϕ.sub.j) 104 are equal to each other (ϕ.sub.i=ϕ.sub.j) and thus the relative pitch angle alignment (Δϕ.sub.ij) 102 is equal to zero.

[0243] In FIG. 4C the pitch angle (ϕ.sub.i) 104 is equal to zero and the pitch angle (ϕ.sub.j) 104 is different from zero and thus the relative pitch angle alignment (Δϕ.sub.ij) 102 is different from zero.

[0244] In FIG. 4D the pitch angle (ϕ.sub.i) 104 is different from zero and the pitch angle (ϕ.sub.j) 104 is different from zero. The pitch angle (ϕ.sub.i) 104 is numerical larger than the pitch angle (ϕ.sub.j) 104 i.e. ϕ.sub.i>ϕ.sub.j. Thus the relative pitch angle alignment (Δϕ.sub.ij) 102 is different from zero.

[0245] The principles apply to a combination of (two) rotor blades 106 (not shown) for rotary devices with three or n-rotor blades. In example a rotary device with three blades, (1,2,3) or (A, B, C) will have the combination of rotor blades 106 ij=(12, 13, 23), ij=(AB, AC, BC).

[0246] FIG. 5 illustrates a rotary device 10; in this case a wind turbine generator 12. The rotary device 10 comprises a rotor 14 with a set of rotor blades 20. The set of rotor blades 20 comprises three rotor blades 22A, 22B, 22C.

[0247] FIG. 6 illustrates a sensory arrangement on blades 22A, 22B, 22C of a rotary device 10.

[0248] The rotary device 10 is a wind turbine generator (WTG) 12 with a rotor 14. The blades 22A, 22B, 22C is a set of rotor blades 20. Each blade 22A, 22B, 22C comprises a set of blade sensors 40A, 40B, 40C. In the present case each set of blade sensors 40A, 40B, 40C comprises a blade sensor 42A, 42B, 42C.

[0249] A sensor 42 is configured to be in communication with a controller 62 or computational means 60. The communication may be wired or wireless as illustrated here.

[0250] The sensors 42 may be implanted as a sensor node comprising essential processing and configuration means.

[0251] FIG. 7 illustrates further aspects of sensory arrangement on a rotary device 10.

[0252] The rotary device 10 is a wind turbine generator (WTG) 12 with a rotor 14. The rotary device 10 comprises a set of rotor blades 20. The set of rotor blades 20 is three rotor blades 22A, 22B, 22C.

[0253] Each blade 22A, 22B, 22C comprises a set of blade sensors 40A, 40B, 40C. In the present case each set of blade sensors 40A, 40B, 40C comprises a blade sensor 42A, 42B, 42C.

[0254] A further sensor 42 is shown. In this embodiment, the further sensor is a rotary sensor (RPM-sensor or vibration sensor) such as a high sampling speed sensor measuring the rotational speed. The system may be configured for an act of calibrating 120 as shown in FIG. 1 and based on sensors 42ABC, that is performed against at least one other sensor 42 from the rotary device 10.

[0255] The computational means 60 or controller 62 may be a single unit or distributed as illustrated here.

[0256] FIG. 8 illustrates multiple sensor node arrangement options and illustrates arrangements of sensors 42A, 42B, 42C on blades 22A, 22B, 22C.

[0257] The figure illustrates a rotary device 10 being a wind turbine generator (WTG) 12 having a rotor 14.

[0258] The rotary device 10 comprises a set of rotor blades 20. The set of rotor blades 20 is three rotor blades 22A, 22B, 22C.

[0259] Each blade 22A, 22B, 22C comprises a set of blade sensors 40A, 40B, 40C. In the present case each set of blade sensors 40A, 40B, 40C comprises three blade sensors 42A, 42B, 42C.

[0260] A set of sensors 40 may be understood as a sensor node with one or more sensors 42.

[0261] Such sensor node may comprise processors or means to configure, collect, store and process sensor data generated. A sensor node may have communication means to communicate with a controller (not shown) or other sensor nodes. A sensor node may have means to synchronize 160 (as illustrated previously) say sensors 42A, 42B and 42C data.

[0262] FIG. 9 illustrates a rotary device 10 with a blade pitch alignment monitoring system 50 with relative blade pitch angle alignment 102 (not shown) in interaction with a remote/cloud based operating/monitoring system 70.

[0263] The rotary device 10 is a wind turbine generator (WTG) 12 with a rotor 14. The

[0264] The rotary device 10 comprises a set of rotor blades 20. The set of rotor blades 20 is three rotor blades 22A, 22B, 22C.

[0265] Each blade 22A, 22B, 22C comprises a set of blade sensors 40A, 40B, 40C. In the present case each set of blade sensors 40A, 40B, 40C comprises a blade sensor 42A, 42B, 42C.

[0266] The data sets 30 are processed by computational means 60 in or by the wind turbine controller 62. The controller 62 may have a clock for generating a timestamp 34. In this case the time stamp is further synchronized and “delivered” from a global time server 34. Hence the datasets 30 may be timestamped data 32. Alternatively, each sensor node 42 may be synchronized and the timestamp 34 may be applied at sensor node level.

[0267] The system 50 may interact with a operator system 74, a mobile device 76, a client server 77 and a storage or database 80 via a cloud/connection 70 service. Further access or mirroring or monitoring may be available via the cloud 70 for long term monitoring, alerts or service programmes.

[0268] The methods and act disclosed herein 100 may be performed in a single processor device or be distributed.

[0269] FIG. 10 illustrates aspects of relative aerodynamic efficiency 154 for different rotor sectors 18I-IV i.e. as a function of swept area 16. The swept area 16 is here divided in four sectors 18 by the dotted lines.

[0270] In the FIG. 11 example, the swept area 16 by the rotor 14 is divided into eight equally sized sectors 18I-VIII, of each 45° by the four dotted lines—but any other division of the swept area 16 by the rotor 14 into equally sized sectors can be relevant. The relative difference in between the specific blade's 22 aerodynamic efficiency in a specific sector 18I of the swept area 16 by the rotor 14 can be monitored over time by comparing acceleration and triangular movements in rotor and in individual blades in the time period where this specific blade (2) is located/operating in this specific sector of the swept area.

[0271] FIGS. 12 A and B illustrates further classification of relative blade pitch monitoring and/or relative aerodynamic efficiency in different operational circumstances or sectors 18.

[0272] In 12A the monitoring of relative imbalance in blade aerodynamic efficiency which can be due to blade damage etc. Monitor over time and compare acceleration-, triangular movements in rotor and in individual blades each time while blade 22A, B and C is operating in dotted area or sector 18 of the swept area 16.

[0273] FIG. 12B illustrates monitoring asymmetry in a blocking zone in front of rotor 14. That is monitoring over time and comparing acceleration-, triangular movements in rotor 14 and in individual blades 22 each time while blade 22A (or B or C) is operating in/dashed area/sector 18I and in \-dashed area/sector 1811.

[0274] FIGS. 13 to 15 relate to the examples as described.