Due to a production error, the equation in section 2.2.1 Global Controller was incorrect.
In section 3.2 Simulation Results: Disturbance Observer Variation, Resulting System Dynamics and Mechanical Loads, at the beginning of subsection Pole locations, Figure 5 instead of Figure 4 was incorrectly referenced.
Due to a production error, the equations in section Discussion, subsection Pole Locations were incorrect.
Due to a production error, the equation in section Error-feedback gains (page 16) was incorrect.
Due a production error, the first paragraph in section Wind speed reconstruction and actuation signals was incorrect. You can find the correct paragraph below:
With the mitigated error-feedback gains , the reconstructed states , especially the reconstructed wind speeds , are mitigated, too (see Eq. 711): While the reconstructed wind speed of a single and arbitrary time point t = t1 decreases steadily for the wind speed observer design with a local Lyapunov approach (i.e., 10, see left column in Figure 6), the reconstructed wind speed for the wind speed observer design with a global Lyapunov approach decreases unsteadily (i.e., , corresponding to the unsteady decrease of the mean Euclidean norm of the wind error state gains of the global wind speed observers (with (w [A, E], see Table 3; i.e., )10
In the same section, footnotes 12 and 13 were assigned incorrectly, and these have been replaced with footnote 10 in the updated article.
10The global and local wind speed observers E and J are not taken into account, because of their (closed-loop) pole locations, which are moved beyond the open-loop pole locations, as explained before in the subsection Pole locations.
Footnote 12 was also incorrect, the correct version is:
12with two exceptions for the tower side-to-side-bending moments and (see Figure 8B and line 7 in Table A9 as well as line 7 in Table A10.
Due to a production error, section Load Mitigation, paragraph number 3, appears to be interrupted and broken into two parts. This has been corrected into one single paragraph.
In the Appendix, part of section Specification of the LMI constraints was not included in the article. The corrected entire section appears below:
To calculate the mean Euclidian norm of the error-feedback gains [see (26)] and the average, mean Euclidian norm [see (27)] the worksheet Uebersicht_L_Matrizen_Pitchwinkel-YYYY_MM_DD.xlsx is used.
In the Appendix, the section Load Analysis was not included in the article. This has now been added to the article, you can find it below:
Load analysis
For the ultimate loads maxw and fatigue loads resulting from five different wind speed observers (i.e., for the and ; see Figure 8), the steady increase or decrease of the loads is evaluated separately for each of the two observer approaches (see Table A9) and in comparison to each other (see Table A10).
Due to a production error, Tables A9 and A10 in the Appendix were not included in the article, and the layout of Tables A1–A8 in the Appendix was incorrect. The corrected Tables are listed below:
The font color has been corrected in the table captions and in the body of the text, throughout the article.
The publisher apologizes for this mistake. The original version of this article has been updated.
TABLE A1
| i | vc,i | βc,i | TG,c,i | |
|---|---|---|---|---|
| 1 | 3 | 0 | 2.912 | 3.4 |
| 2 | 4 | 0 | 5.193 | 4.6 |
| 3 | 5 | 0 | 8.079 | 5.7 |
| 4 | 6 | 0 | 11.646 | 6.9 |
| 5 | 7 | 0 | 15.843 | 8.0 |
| 6 | 8 | 0 | 20.671 | 9.2 |
| 7 | 9 | 0 | 26.128 | 10.3 |
| 8 | 9.5 | 0 | 29.094 | 10.9 |
| 9 | 10 | 0 | 32.267 | 11.4 |
| 10 | 10.5 | 0 | 35.547 | 12.0 |
| 11 | 11 | 0 | 40.433 | 12.1 |
| 12 | 11.5 | 2.2 | 43.094 | 12.1 |
| 13 | 12 | 4.1 | 43.094 | 12.1 |
| 14 | 12.5 | 5.5 | 43.094 | 12.1 |
| 15 | 13 | 6.6 | 43.094 | 12.1 |
| 16 | 14 | 8.6 | 43.094 | 12.1 |
| 17 | 15 | 10.4 | 43.094 | 12.1 |
| 18 | 16 | 12.0 | 43.094 | 12.1 |
| 19 | 17 | 13.4 | 43.094 | 12.1 |
| 20 | 18 | 14.8 | 43.094 | 12.1 |
| 21 | 19 | 16.1 | 43.094 | 12.1 |
| 22 | 20 | 17.4 | 43.094 | 12.1 |
| 23 | 21 | 18.6 | 43.094 | 12.1 |
| 24 | 22 | 19.7 | 43.094 | 12.1 |
| 25 | 23 | 20.8 | 43.094 | 12.1 |
| 26 | 24 | 22.0 | 43.094 | 12.1 |
| 27 | 25 | 23.0 | 43.094 | 12.1 |
States of the i steady state operations points OPi of the NREL FAST 5MW reference wind turbine with the wind speed vc,i, rotor rotational speed , generator torque TG,c,i and pitch angle βc,i.
TABLE A2
| 0 | 1 | 0 | 1 | 0 | ||
| -21.82 | -5.41 | -21.82 | -5.41 | 9.58 | ||
| - | - | 0 | 0 | -0.25 | ||
| 0 | 1 | 0 | 1 | 0 | ||
| -21.88 | -5.36 | -21.88 | -5.36 | 9.51 | ||
| - | - | 0 | 0 | -0.25 | ||
| 0 | 1 | 0 | 1 | 0 | ||
| -21.92 | -5.35 | -21.92 | -5.35 | 9.48 | ||
| - | - | 0 | 0 | -0.25 | ||
| 0 | 1 | 0 | 1 | 0 | ||
| -21.95 | -5.30 | -21.95 | -5.30 | 9.38 | ||
| - | - | 0 | 0 | -0.25 |
State matrices and augmented state matrices of the lade model (for the submodels i ∈ [15,18]).
TABLE A3
| 0 | 0 | 0 | 0 | ||
| -563.53 | 0 | -563.53 | 0 | ||
| - | - | 0 | 0 | ||
| 0 | 0 | 0 | 0 | ||
| -589.16 | 0 | -589.16 | 0 | ||
| - | - | 0 | 0 | ||
| 0 | 0 | 0 | 0 | ||
| -606.41 | 0 | -606.41 | 0 | ||
| - | - | 0 | 0 | ||
| 0 | 0 | 0 | 0 | ||
| -628.21 | 0 | -628.21 | 0 | ||
| - | - | 0 | 0 |
Input matrices and augmented input matrices of the lade model (for the submodels i ∈ [15,18]).
TABLE A4
| 1 | 0 | 1 | 0 | 0 |
Common output matrix and augmented common output matrix of the lade model (for all submodels).
TABLE A5
| 3.61 | 3.61 | ||
| 0 | 0 | ||
| - | 13 | ||
| 3.15 | 3.15 | ||
| 0 | 0 | ||
| - | 14 | ||
| 2.73 | 2.73 | ||
| 0 | 0 | ||
| - | 15 | ||
| 2.44 | 2.44 | ||
| 0 | 0 | ||
| - | 16 |
Steady states and augmented steady states of the lade model (for the submodels i ∈ [15,18]).
TABLE A6
| βc,15 | 6.6 |
| TG,15 | 43.094 |
| βc,16 | 8.6 |
| TG,16 | 43.094 |
| βc,17 | 10.4 |
| TG,17 | 43.094 |
| βc,18 | 12.0 |
| TG,18 | 43.094 |
Steady state pitch angle βc,i and generator torque TG,i (for the submodels i ∈ [15,18]).
TABLE A7
| -1.31 | |
| 0 | |
| -1.03 | |
| 0 | |
| -0.85 | |
| 0 | |
| -0.71 | |
| 0 |
State feedback matrices of the (rigid body) otion drive train model (for the submodels i ∈ [15,18]).
TABLE A8
| 3.87 | 2.81 | 2.04 | 1.28 | 0.30 | 4.06 | 3.02 | 1.79 | 0.38 | -1.35 | |
| -13.31 | -15.30 | -9.80 | -5.92 | -4.22 | -14.19 | -12.90 | -8.78 | -5.23 | -4.46 | |
| 2.56 | 0.88 | 1.21 | 1.43 | 1.31 | 2.27 | 1.90 | 1.61 | 1.11 | 0.39 | |
| 3.87 | 2.81 | 2.04 | 1.28 | 0.30 | 4.07 | 3.07 | 1.84 | 0.43 | -1.30 | |
| -13.44 | -15.45 | -9.95 | -6.05 | -4.28 | -14.33 | -13.14 | -9.18 | -5.57 | -4.85 | |
| 2.56 | 0.88 | 1.20 | 1.43 | 1.31 | 2.26 | 1.91 | 1.61 | 1.12 | 0.40 | |
| 3.88 | 2.81 | 2.04 | 1.28 | 0.30 | 4.07 | 3.08 | 1.85 | 0.44 | -1.29 | |
| -13.49 | -15.50 | -10.01 | -6.10 | -4.31 | -14.39 | -13.22 | -9.30 | -5.68 | -4.98 | |
| 2.56 | 0.88 | 1.20 | 1.43 | 1.31 | 2.26 | 1.92 | 1.61 | 1.12 | 0.40 | |
| 3.88 | 2.81 | 2.04 | 1.28 | 0.29 | 4.08 | 3.13 | 1.90 | 0.50 | -1.23 | |
| -13.60 | -15.62 | -10.13 | -6.19 | -4.33 | -14.51 | -13.43 | -9.70 | -6.00 | -5.39 | |
| 2.56 | 0.88 | 1.20 | 1.43 | 1.31 | 2.26 | 1.93 | 1.61 | 1.13 | 0.40 |
Error state feedback gain matrices of the blade model based wind speed observers for:
- Lyapunov approach with
- Lyapunov approach with
- submodels i ∈ [15,18]
- matrix elements j ∈ [1,3].
TABLE A9
| Loads | ||
|---|---|---|
| TwrBsMyt | maxA maxB maxC maxD maxE | maxF maxG maxH maxI maxJ |
| TwrBsMxt | maxA maxB maxC maxD maxE | maxF ≈ maxG maxH maxI maxJ |
| RootMxb1 | maxA maxB maxC maxD maxE | maxF maxG maxH maxI maxJ |
| RootMyb1 | maxA maxB maxC maxD maxE | maxF maxG maxH maxI maxJ |
| ΔT | maxA maxB maxC maxD maxE | maxF maxG maxH maxI ≈ maxJ |
| TwrBsMyt | ||
| TwrBsMxt | ||
| ΔT | ||
| RootMyb1 | ||
| RootMxb1 |
Analysis of the ultimate loads maxw and fatigue loads resulting from five different wind speed observers regarding the steady increase or decrease of the loads (evaluated separately for each of the two Lyapunov approaches with for the and with for the based on the loads depicted in Figure 8).
TABLE A10
| Loads | ⇔ | ⇔ | ⇔ | ⇔ | ⇔ |
|---|---|---|---|---|---|
| TwrBsMyt | maxA maxF | maxB maxG | maxC maxH | maxD maxI | maxE maxJ |
| TwrBsMxt | maxA maxF | maxB maxG | maxC maxH | maxD maxI | maxE maxJ |
| RootMyb1 | maxA maxF | maxB maxG | maxC maxH | maxD maxI | maxE maxJ |
| RootMxb1 | maxA maxF | maxB maxG | maxC maxH | maxD maxI | maxE maxJ |
| ΔT | maxA maxF | maxB maxG | maxC maxH | maxD maxI | maxE maxJ |
| TwrBsMyt | |||||
| TwrBsMxt | |||||
| RootMyb1 | |||||
| RootMxb1 | |||||
| ΔT |
Analysis of the ultimate loads maxw and fatigue loads resulting from five different wind speed observers regarding the steady increase or decrease of the loads (comparing both Lyapunov approaches with each other with for the and with for the based on the loads depicted in Figure 8).
Summary
Keywords
global and local Lyapunov approach, Takagi–Sugeno framework, model-based controller and observer design, feedforward-feedback control, linear-matrix-inequality and pole region-based controller design, wind turbine application, elaborated wind turbine simulation model, load analysis
Citation
Frontiers Production Office (2023) Erratum: Global versus local Lyapunov approach used in disturbance observer-based wind turbine control. Front. Control. Eng. 4:1279811. doi: 10.3389/fcteg.2023.1279811
Received
18 August 2023
Accepted
18 August 2023
Published
03 November 2023
Approved by
Frontiers Editorial Office, Frontiers Media SA, Switzerland
Volume
4 - 2023
Updates
Copyright
© 2023 Frontiers Production Office.
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