 | Hau E. Wind turbines: fundamentals, technologies, application, economics. - 3rd, transl. ed. - Heidelberg et al.: Springer, 2013. - xviii, 879 p.: ill., tab. - Bibliogr. at the end of the chapters. – Sub. ind.: p.871-879. - ISBN 978-3-642-27150-2
Шифр: (И/З 6-H37) 02
|
1 Windmills and Windwheels ................................... 1
1.1 The Origins of Windmills ................................... 1
1.2 European Windmills ......................................... 4
1.3 Economic Importance of Historical Windmills ............... 11
1.4 Scientific and Technical Development of Windmills ......... 13
1.5 The American Wind Turbine ................................. 17
References ................................................ 21
2 Electrical Power from the Wind - The First Attempts ....... 23
2.1 Poul La Cour - A Pioneer in Denmark ....................... 23
2.2 Large Wind Power Plants - Ambitious Projects in Germany ... 28
2.3 1250 kW from the Wind - The First Large Wind Turbine in
the US .................................................... 33
2.4 Wind Turbines in the Fifties - Before the "Energy
Crisis" ................................................... 36
2.5 After the Energy Crisis - A New Start toward Modern Wind
Power ..................................................... 43
2.6 The Large Experimental Turbines of the Eighties ........... 46
2.7 First Successes with the Small Wind Turbines in Denmark ... 57
2.8 The Wind Farms in the United States ....................... 58
References ................................................ 63
3 Basic Concepts of Wind Energy Converters .................. 65
3.1 Rotors with a Vertical Axis of Rotation ................... 66
3.2 Horizontal Axis Rotors .................................... 69
3.3 Wind Energy Concentrators ................................. 72
3.4 Terms and Expressions ..................................... 77
References ................................................ 78
4 Physical Principles of Wind Energy Conversion ............. 79
4.1 Betz's Elementary Momentum Theory ......................... 79
4.2 Wind Energy Converters Using Aerodynamic Drag or Lift ..... 84
References ................................................ 87
5 Rotor Aerodynamics ........................................ 89
5.1 Mathematical Models and Calculations ...................... 90
5.1.1 Blade Element Theory ............................... 91
5.1.2 Vortex Model of Rotor Flow ......................... 96
5.1.3 Numeric Flow S imul ation .......................... 97
5.1.4 The Rotor Wake ..................................... 99
5.2 Rotor Power Characteristics .............................. 102
5.2.1 Power and Torque Characteristics .................. 102
5.2.2 Power Characteristics of Various Rotor
Configurations .................................... 104
5.3 Aerodynamic Power Control ................................ 106
5.3.1 Power Control by Rotor Blade Pitching ............. 107
5.3.2 Passive Stall Control with Fixed Blade Pitch ...... 111
5.3.3 Active Stall Control .............................. 115
5.3.4 Transient Aerodynamic Effects and Boundary-Layer
Control ........................................... 117
5.3.5 Turning the Rotor Out of the Wind ................. 119
5.4 The Aerodynamic Airfoil .................................. 120
5.4.1 Characteristic Properties ......................... 120
5.4.2 Airfoil Geometry and Classification ............... 123
5.4.3 Laminar Airfoils .................................. 128
5.4.4 Influence on the Power Coefficient of the Rotor ... 132
5.5 Rotor-Design Features and Power Characteristics .......... 134
5.5.1 Number of Rotor Blades ............................ 135
5.5.2 Optimum Shape of the Rotor Blades ................. 136
5.5.3 Rotor Blade Twist ................................. 143
5.5.4 Blade Thickness ................................... 145
5.5.5 Design Tip-Speed Ratio of the Rotor ............... 146
5.6 Existing Rotor Blade Designs ............................. 148
5.7 Yaw Control of the Rotor ................................. 152
5.8 Aerodynamics of Vertical-Axis Rotors ..................... 156
5.9 Experimental Rotor Aerodynamics .......................... 160
5.9.1 Measurements on Models in the Wind Tunnel ......... 160
5.9.2 Measurements on Site .............................. 163
References ............................................... 164
6 Loads and Structural Stresses ........................... 167
6.1 Loads on the Wind Turbine ................................ 168
6.2 Coordinate Systems and Terminology ....................... 170
6.3 Sources of Loading ....................................... 171
6.3.1 Gravity and Inertial Loads ........................ 172
6.3.2 Uniform and Steady-State Air Flow ................. 173
6.3.3 Vertical Wind Shear and Cross Winds ............... 177
6.3.4 Cross Wind on the Rotor ........................... 178
6.3.5 Tower Interference ................................ 179
6.3.6 Wind Turbulence and Gusts ......................... 183
6.4 Design Load Assumptions .................................. 187
6.4.1 International and National Design Standards ....... 188
6.4.2 IEC Classes of Wind Turbines and German Wind
Zones ............................................. 191
6.4.3 Normal Wind Conditions ............................ 193
6.4.4 Extreme Wind Conditions ........................... 194
6.4.5 Other Climatic and Environmental Influences ....... 195
6.4.6 Other External Conditions ......................... 197
6.4.7 Safety Factors .................................... 198
6.5 Operational Status and Load Cases ........................ 199
6.5.1 Normal Operation .................................. 199
6.5.2 Technical Faults .................................. 201
6.6 Structural Stresses in the Wind Turbine .................. 203
6.6.1 Kind of Stressing ................................. 203
6.6.2 Load Spectra ...................................... 205
6.7 Mathematical Models of Structural Dynamics ............... 208
6.7.1 Functional and Structural Modelling of the Wind
Turbine ........................................... 208
6.7.2 Representation of the Wind Turbulence ............. 209
6.7.3 Analytical Approaches and Numerical Computer
Codes ............................................. 213
6.8 Conceptual Design Features and Structural Stresses ....... 215
6.8.1 Number of Rotor Blades ............................ 215
6.8.2 Rotor Hub Hinges in Two-Blade Rotors .............. 217
6.8.3 Stiffness of the Rotor Blades ..................... 220
6.8.4 Power Control System .............................. 221
6.8.5 Rotor Speed Flexibility and Variable-Speed
Operation ......................................... 223
6.9 Measuring the Structural Stresses ........................ 226
6.9.1 Rotor Blade Testing ............................... 227
6.9.2 Data Acquisition Systems and Field Measurements ... 228
References ............................................... 230
7 Vibration Characteristics ................................ 233
7.1 Exciting Forces and Vibrational Degrees of Freedom ....... 234
7.2 Aeroelastic Stability of Rotor Blades .................... 236
7.2.1 Static Divergence ................................. 236
7.2.2 Natural Frequencies and Vibration Modes ........... 237
7.2.3 Typical Rotor Blade Vibrations .................... 239
7.3 Torsional Vibration of the Drive Train ................... 242
7.3.1 Mathematical Model ................................ 242
7.3.2 Equivalent Mechanical Models for the Electrical
Grid Coupling ..................................... 246
7.3.3 Natural Frequencies and Vibration Modes ........... 247
7.3.4 Excitations and Resonances ........................ 249
7.4 Dynamics of the Yaw System ............................... 252
7.4.1 Modelling and Moments Around the Yaw Axis ......... 252
7.4.2 Excitation and Resonances ......................... 254
7.5 Vibration of the Whole Wind Turbine ...................... 256
7.5.1 Tower Stiffness ................................... 256
7.5.2 Vibrational Characteristics of Existing Wind
Turbines .......................................... 258
7.6 Mathematical Simulation .................................. 264
References ............................................... 267
8 Rotor Blades ............................................. 269
8.1 Materials ................................................ 270
8.2 Aircraft Wings as Model .................................. 272
8.3 Experimental Designs of Rotor Blades in the Past ......... 274
8.3.1 Revited Aluminium Construction .................... 275
8.3.2 Steel Designs ..................................... 277
8.3.3 Traditional Wood Construction ..................... 280
8.3.4 Previous Designs with Fibre-Reinforced
Composites ........................................ 281
8.3.5 Wood/Epoxy Composites ............................. 286
8.4 Modern Fibre-Reinforced Composite Blades ................. 287
8.4.1 Fibre Composites Technology ....................... 287
8.4.2 Structural Design of the Rotor Blades ............. 289
8.4.3 Manufacturing Methods ............................. 290
8.5 Blade Connection to the Rotor Hub ........................ 293
8.6 Comparison of Rotor Blade Designs ........................ 296
8.7 Aerodynamic Brakes on Stall-Controlled Rotors ............ 300
8.8 Lightning Protection ..................................... 302
8.9 Ice Warning and De-icing ................................. 303
References ............................................... 304
9 Mechanical Drive Train and Nacelle ....................... 305
9.1 Fundamental Considerations of Power Transmission ......... 306
9.2 Previous Experimental Designs ............................ 309
9.2.1 Generator in the Tower Base ....................... 310
9.2.2 Vertically Positioned Generator in the Tower
Head .............................................. 310
9.3 Current Standard Designs ................................. 312
9.3.1 Gearbox between Rotor and Generator ............... 312
9.3.2 Direct Rotor-Driven Generator ..................... 314
9.4 Rotor Hub ................................................ 318
9.4.1 Cast Steel Rotor Hubs for Three-Blade Rotors ...... 320
9.4.2 Rotor Hub Concepts for Two-Bladed Rotors .......... 321
9.5 Blade Pitch Mechanism .................................... 325
9.5.1 Rotor Blade Bearings .............................. 327
9.5.2 Blade Pitch Systems with Hydraulic Drive .......... 329
9.5.3 Electrically Driven Blade Pitch Systems ........... 333
9.5.4 Passive Blade Pitching ............................ 335
9.5.5 Redundancy and Safety Issues ...................... 336
9.6 Rotor Shaft and Bearing Assembly ......................... 338
9.6.1 Bearing Technology ................................ 338
9.6.2 Rotor Shaft with Separate Bearings ................ 341
9.6.3 Three-Point Suspension of Rotor Shaft and
Gearbox ........................................... 343
9.6-4 Rotor Shaft Integrated into the Gearbox ........... 344
9.6.5 The "Single-Bearing" Concept ...................... 345
9.6.6 Rotor Support on a Fixed Axle ..................... 346
9.7 Rotor Brake .............................................. 347
9.8 Gearbox .................................................. 350
9.8.1 Gearbox Configurations ............................ 350
9.8.2 External Load Specifications for the Gearbox ...... 354
9.8.3 Internal Gearbox Dimensioning and Design .......... 357
9.8.4 Efficiency and Noise Emission ..................... 358
9.9 Variable-Speed Power-Splitting Gearboxes ................. 361
9.10 Torsional Flexibility in the Mechanical Drive Train ...... 363
9.11 Installation of the Electric Generator ................... 366
9.12 Nacelle .................................................. 368
9.12.1 Auxiliary Systems ................................. 368
9.12.2 Load Carrying Concept ............................. 371
9.12.3 External Shape - Aesthetic Aspects ................ 374
9.13 Yaw System ............................................... 377
9.14 Assembly and Functional Testing .......................... 280
References ............................................... 382
10 Electrical System ........................................ 385
10.1 Synchronous and Asynchronous Generator ................... 386
10.1.1 Synchronous Generator ............................. 386
10.1.2 Induction Generator ............................... 390
10.1.3 Generator with Permanent Excitation ............... 394
10.2 Assessment Criteria for Using Generators in Wind
Turbines ................................................. 398
10.3 Fixed-Speed Generator Systems ............................ 401
10.3.1 Synchronous Generator Directly Coupled to the
Grid .............................................. 401
10.3.2 Induction Generator Directly Coupled to the Grid .. 403
10.3.3 Variable-Slip Induction Generator ................. 405
10.3.4 Multi-Speed Generator Systems ..................... 406
10.4 Variable Speed Generator Systems with Inverter ........... 408
10.4.1 Frequency Inverters ............................... 409
10.4.2 Synchronous Generator with Inverter ............... 411
10.4.3 Induction Generator with Oversynchronous Cascade .. 413
10.4.4 Double-Fed Induction Generator .................... 414
10.5 Directly Rotor-Driven Variable-Speed Generators .......... 417
10.5.1 Synchronous Generator with Electric Excitation .... 417
10.5.2 Direct-Drive Generators with Permanent-Magnet
Excitation ........................................ 419
10.6 Complete Electrical System of a Wind Turbine ............. 421
10.6.1 Large Turbines .................................... 421
10.6.2 Small Wind Turbines ............................... 424
10.7 Comparison of Electrical Concepts ........................ 426
References ............................................... 428
11 Control Systems and Operational Sequence ................. 429
11.1 Input Data Measurement ................................... 430
11.1.1 Wind Measuring System ............................. 431
11.1.2 Measuring Electric Power .......................... 434
11.1.3 Other Input Data .................................. 435
11.2 Basic Technology of Controllers .......................... 435
11.3 Yaw Control .............................................. 437
11.4 Power Control with Rotor Blade Pitching .................. 438
11.4.1 System Characteristics and Analytical Design
Methods ........................................... 440
11.4.2 Fixed-Speed Generators Directly Coupled to the
Grid .............................................. 443
11.4.3 Variable-Speed Operation with Frequency
Converter ......................................... 448
11.4.4 Isolated Operation without Grid ................... 450
11.5 Power Limiting by Aerodynamic Stall ...................... 452
11.5.1 Parallel-Grid Operation ........................... 452
11.5.2 Isolated Operation ................................ 453
11.5.3 Active Stall Control .............................. 454
11.6 Operational Sequence and Safety System ................... 457
11.6.1 Operational States ................................ 457
11.6.2 Safety System ..................................... 459
11.7 Control System Implementation ............................ 460
11.8 Interaction with the Grid ................................ 462
References ............................................... 465
12 The Tower ................................................ 467
12.1 Tower Configurations ..................................... 468
12.2 Strength and Stiffness Design ............................ 471
12.3 Tower Demensioning Conforming to German Building
Regulations .............................................. 473
12.4 Free-Standing Tubular-Steel Towers ....................... 474
12.4.1 Stiffness and Structural Mass ..................... 474
12.4.2 Manufacturing Techniques and Construction ......... 477
12.4.3 Climbing Aids and Internal Installations .......... 480
12.5 Lattice Towers ........................................... 483
12.6 Concrete Towers .......................................... 487
12.7 Concrete-Steel Hybrid Towers ............................. 492
12.8 Comparison of Different Tower Concepts ................... 494
12.9 Increasing the Height with Different Tower Concepts ...... 496
12.10 The Foundation .......................................... 499
References ............................................... 503
13 The Wind Resource ........................................ 505
13.1 Causes of the Wind and of the Power in the Wind .......... 505
13.2 Global Distribution of Wind Resources .................... 508
13.3 Wind Resources in Europe ................................. 516
13.4 Characteristic Parameters of the Wind .................... 517
13.4.1 Mean Annual Wind Speed and Wind Speed Frequency
Distribution ...................................... 517
13.4.2 Increase in Wind Speed with Altitude .............. 520
13.4.3 Steadiness of the Wind ............................ 524
13.4.4 Wind Turbulence and Gusts ......................... 529
13.5 Topography and Local Wind Flow ........................... 532
13.6 Measuring and Determining the Wind Speed ................. 534
13.6.1 Measuring Techniques .............................. 534
13.6.2 Ascertaining the Wind Data and the Energy Yield
from the European Wind Atlas ...................... 539
13.6.3 Numeric Models of Three-Dimensional Wind Fields ... 542
13.7 About the Wind Energy Potential .......................... 543
References ............................................... 547
14 Power Output and Energy Yield ............................ 549
14.1 From Rotor Power Characteristics to Turbine Power Curve .. 550
14.1.1 Installed Generator Power and Rotor Speed ......... 550
14.1.2 Losses due to Power Control and Operational
Sequence .......................................... 554
14.1.3 Efficiencies in the Mechanical-Electrical Energy
Conversion ........................................ 557
14.1.4 Power Coefficients of Today's Turbines ............ 559
14.2 Determination of the Power Curve ......................... 560
14.2.1 Definitions, Characteristics and Warranty ......... 561
14.2.2 Measuring the Power Curve ......................... 563
14.3 Site-Related Influences on the Power Curve ............... 569
14.3.1 Complex Terrain ................................... 569
14.3.2 Air Density ....................................... 570
14.3.3 Turbulence ........................................ 573
14.3.4 Other Weather-Related Influences .................. 575
14.3.5 Soiling of the Rotor Blades ....................... 575
14.4 Uniformity of Power Output ............................... 576
14.5 Annual Energy Yield ...................................... 579
14.5.1 Method of Calculation ............................. 579
14.5.2 Approximate Calculation of the Energy Yield ....... 581
14.5.3 Technical Availability ............................ 584
14.5.4 Safety Deductions for Economic Calculations ....... 588
14.6 Wind Regime and Energy Yield ............................. 589
14.7 Major Design Features and Energy Yield ................... 591
14.7.1 Rotor Power Coefficient ........................... 592
14.7.2 Rotor Diameter .................................... 593
14.7.3 Optimal Rotor Speed and Variable Rotor Speed
Operation ......................................... 594
14.7.4 Power Control: Blade Pitch Contra Stall ........... 597
14.7.5 Installed Generator Power ......................... 598
14.7.6 Rotor Hub Height .................................. 600
14.7.7 Operational Wind Speed Range ...................... 601
14.7.8 Efficiency of a Wind Turbine as Energy Converter .. 602
References ............................................... 603
15 Environmental Impact ..................................... 605
15.1 Hazards for the Environment .............................. 606
15.1.1 How Far Can a Rotor Blade Fly? .................... 606
15.1.2 Safety Risks ...................................... 609
15.2 Wind Turbine Noise ....................................... 610
15.2.1 Acoustic Parameters and Permissible Noise Levels .. 610
15.2.2 Noise Sources in Wind Turbines .................... 613
15.2.3 Noise Emission of Current Wind Turbines ........... 617
15.3 Shadow Effects ........................................... 622
15.4 Interference with Radio and Television Signals ........... 625
15.5 Impact on Bird Life ...................................... 628
15.6 Land Use ................................................. 629
15.7 Visual Impact on the Landscape ........................... 631
15.8 Utilisation of Wind Energy and Climate Protection ........ 633
15.8.1 Effect on the Local Climate ....................... 633
15.8.2 Utilisation of Wind Power and C02 Emissions ....... 634
References ............................................... 636
16 Commercial Applications of Wind Turbines ................. 637
16.1 Stand-Alone Wind Turbine Applications .................... 638
16.1.1 Autonomous Power Supply - Storage Problems ........ 639
16.1.2 Residential Heating with Wind Energy .............. 645
16.1.3 Pumping Water ..................................... 648
16.1.4 Desalination of Sea Water ......................... 650
16.2 Small Grids with Diesel Generators and Wind Turbines ..... 653
16.3 Wind Turbines Connected with Large Grids ................. 657
16.3.1 Distributed Wind Turbines Operated by Private
Consumers ......................................... 657
16.3.2 Wind Park Installations ........................... 658
16.4 Integration into the Utility Generation System ........... 662
16.4.1 Operational Strategies and Control Issues ......... 663
16.4.2 Adaption of the Utility Grids to Renewable
Energy Utilisation ................................ 665
16.4.3 Contribution to Firm Power ........................ 666
16.5 Wind Turbine Industry and Market ......................... 668
16.5.1 Historical Development of the Markets ............. 668
16.5.2 The Wind Turbine Manufacturers .................... 670
16.5.3 Components Industry, Service Providers and Basic
Research .......................................... 672
References ............................................... 675
17 Offshore Wind Energy Utilisation ......................... 677
17.1 Important Technical Issues of Offshore Siting ............ 678
17.1.1 Technical Requirements for the Wind Turbines ...... 678
17.1.2 Foundation on the Sea Floor ....................... 681
17.1.3 Electrical Infrastructure ......................... 688
17.1.4 Transportation and Installation ................... 694
17.2 Operational Issues of Offshore Wind Turbines ............. 697
17.2.1 Accessibility at Poor Weather Conditions .......... 697
17.2.2 Servicing and Maintenance ......................... 699
17.3 Offshore Wind Energy in the North Sea and in the Baltic
Sea ...................................................... 701
17.3.1 Oceanographic Conditions and Wind Resources ....... 701
17.3.2 Legal Situation ................................... 704
17.3.3 Criteria for the Permission ....................... 706
17.3.4 The First Offshore Wind Parks ..................... 708
17.3.5 Commercial Offshore Wind Parks .................... 709
References ............................................... 718
18 Wind Turbine Installation and Operation .................. 719
18.1 Project Development ...................................... 720
18.1.1 Search for a Site and Acquisition of Land Lease
Agreements ........................................ 720
18.1.2 Preplanning and Building Permission ............... 721
18.2 Technical Layout of Wind Park Installations .............. 724
18.2.1 Wind Turbine Spacing .............................. 725
18.2.2 Internal Electrical Cabling ....................... 729
18.2.3 Grid Connection ................................... 732
18.2.4 Site Preparation and Building Activities .......... 738
18.3 Transportation to the Site ............................... 741
18.4 Erection on the Site ..................................... 745
18.4.1 Standard Method ................................... 745
18.4.2 Erection without Heavy Lifting Equipment .......... 749
18.4.3 Extremely Large Installations ..................... 752
18.4.4 Large Experimental Turbines with Two-Bladed Rotor . 755
18.5 Commisioning ............................................. 760
18.5.1 Commercial Wind Turbines .......................... 760
18.5.2 Experimental Turbines and Prototypes .............. 761
18.6 Operation and Monitoring ................................. 763
18.6.1 Acquisition of Operational Data ................... 763
18.6.2 Monitoring of Large Wind Parks .................... 767
18.6.3 Technical Condition Monitoring .................... 768
18.7 Safety Aspects ........................................... 770
18.7.1 Technical Safety Systems .......................... 770
18.7.2 Risks from Extreme Weather Conditions ............. 775
18.8 Maintenance and Repair .............................. 779
18.8.1 Routine Maintenance ............................... 780
18.8.2 Causes of Damage and Repair Risks ................. 781
18.8.3 Statistical Evaluations ........................... 785
References ............................................... 786
19 Wind Turbine Costs ....................................... 789
19.1 Manufacturing Costs and Selling Prices of Wind Turbines .. 790
19.2 Specific Costs and Reference Parameters .................. 791
19.2.1 Structural Masses as a Basis for Determining
the Manufacturing Costs ........................... 792
19.2.2 Structural Masses of Present Wind Turbines ........ 798
19.2.3 Manufacturing Cost Calculation on the Basis
of Mass-Related Cost Figures ...................... 801
19.2.4 Manufacturing Costs and Price Calculation ......... 803
19.2.5 Design Features and Manufacturing Costs ........... 809
19.2.6 Economy of Scale in Series Production ............. 811
19.2.7 Lowering Costs through Further Technical
Development ....................................... 813
19.2.8 Alternative Technical Concepts and Achievable
Costs ............................................. 814
19.2.9 On the Development Costs of Wind Turbines ......... 816
19.2.10 Development of Sales Prices for Wind Turbines .... 817
19.3 Investment Costs for Turnkey Installations ............... 820
19.3.1 Acquisition of the Project Rights ................. 820
19.3.2 Technical Planning and Application for the
Building Permission ............................... 820
19.3.3 Procurement of Wind Turbines ...................... 821
19.3.4 Technical Infrastructure .......................... 822
19.3.5 Organisational Costs .............................. 825
19.3.6 Selected Examples for Turn-Key Costs .............. 826
19.4 Operating and Maintenance Costs .......................... 829
19.4.1 Maintenance and Repairs ........................... 830
19.4.2 Insurances ........................................ 832
19.4.3 Other Operating Costs ............................. 833
19.4.4 Total Annual Operating Costs ...................... 834
19.5 Offshore Projects ........................................ 834
19.5.1 Investment Costs .................................. 834
19.5.2 Operating Costs ................................... 841
References ............................................... 842
20 Wind Turbine Economics ................................... 845
20.1 Corporate Organisation of the Project and Financing ...... 846
20.2 Power Production Costs and Repayment Periods ............. 848
20.2.1 Basics for Calculating the Costs of Electricity ... 849
20.2.2 Static Annuity Approach ........................... 850
20.2.3 Offshore Installations ............................ 854
20.2.4 Dynamic Calculation of Economic Viability ......... 857
20.2.5 Cash-Flow Projection .............................. 859
20.3 Competition with Conventional Energy Sources ............. 863
20.4 Energy Recovery in Wind Turbines ......................... 866
20.5 The Effect of Wind Energy Utilisation on Employment ...... 867
20.6 Macroeconomic Framework and Renewable Energies ........... 868
References ............................................... 870
Subject Index ................................................. 871
|
|
