Content. 0 Questionnaire 87 from Max Frisch

Transcription

1 Content 0 Questionnaire 87 from Max Frisch 1 Introduction to Wind Energy Wind Energy in the year The Demand for Electricity Energy Policy and Governmental Instruments Technological development Historical development of windmills Windmills with a vertical axis Horizontal axis windmills From the post windmill to the Western mill Technical innovations Begin and end of the wind power era in the Occident The period after the First World War until the end of the 1960s The Renaissance of the wind energy after The physics of the use of wind energy Wind power Drag driven rotors Lift driven rotors Comparison of rotors using drag principle and lift principle Wind turbines - design and components Rotor Rotor blade Hub Blade pitch system Drive train Concepts Gearbox Couplings and brakes Generators Auxiliary aggregates and other components Yaw system Heating and cooling Lightning protection Lifting devices... 92

2 X Content Sensors Tower and foundation Tower Foundation Assembly and Production Characteristic wind turbine data The wind Origins of the wind Global wind systems Geostrophic Wind Local wind systems Atmospheric boundary layer Surface boundary layer Vertical wind profile Turbulence intensity Representation of measured wind speeds in the time domain by frequency distribution and distribution functions Spectral representation of the wind Determination of power, yield and loads Yield calculation using wind speed histogram and turbine power curve Yield calculation from distribution function and turbine power curve Power curve measurement Yield prediction of a wind farm Effects of wind and site on the wind turbine loading Wind measurement and evaluation Cup anemometer Ultrasonic anemometer SODAR Prediction of the wind regime Wind Atlas Analysis and Application Programme Meso-Scale models Measure-Correlate-Predict-Methode Blade geometry according to Betz and Schmitz How much power can be extracted from the wind? Froude-Rankine Theorem The airfoil theory Flow conditions and aerodynamic forces at the rotating blade Triangles of velocities Aerodynamic forces at the rotating blade

3 Content XI 5.4 The Betz optimum blade dimensions Losses Profile losses Tip losses Losses due to wake rotation The Schmitz dimensioning taking into account the rotational wake Losses due to wake rotation Wind turbine design in practice Final remark Calculation of performance characteristics and partial load behaviour Method of calculation (blade element momentum method) Dimensionless presentation of the characteristic curves Dimensionless characteristic curves of a turbine with a high tip speed ratio Dimensionless characteristic curves of a turbine with a low tip speed ratio Turbine performance characteristics Flow conditions Turbines with high and low tip speed ratio: a summary Flow conditions in a turbine with a low design tip speed ratio Flow conditions in a turbine with a high design tip speed ratio Behaviour of turbines with high tip speed ratio and blade pitching Extending the calculation method Start-up range of < D (high lift coefficients) Idling range of > D (Glauert s empirical formula) The profile drag The extended iteration algorithm Limits of the blade element theory and three-dimensional calculation methods Lift distribution and three-dimensional effects Dynamic flow separation (Dynamic stall) Method of singularities Computational fluid dynamics applied to wind turbines Examples of CFD application to wind turbines Scaling wind turbines and rules of similarity Application and limits of the theory of similarity Bending stress in the blade root from aerodynamic forces Tensile stress in the blade root resulting from centrifugal forces Bending stresses in the blade root due to weight Change in the natural frequencies of the blade and in the frequency ratios

4 XII Content 7.6 Aerodynamic damping Limitations of up-scaling - how large can wind turbines be? Structural dynamics Dynamic excitations Mass, inertia and gravitational forces Aerodynamic and hydrodynamic loads Transient excitations by manoeuvres and malfunctions Free and forced vibrations of wind turbines - examples and phenomenology Dynamics of the tower-nacelle system Blade vibrations Drive train vibrations Sub-models - overall system Instabilities and further aeroelastic problems Simulation of the overall system dynamics Modelling in simulation programs Application of simulation programs Validation by measurement Guidelines and analysis procedures Certification Standard for certification: IEC Guidelines for the Certification of Wind Turbines by Germanischer Lloyd Guidelines for Design of Wind Turbines by DNV Regulation for Wind Energy Conversion Systems, Actions and Verification of Structural Integrity for Tower and Foundation by DIBt Further standards and guidelines Wind classes and site categories Load case definitions Analysis concepts Ultimate limit state and the concept of partial safety factors Serviceability analysis Basics of fatigue analysis Example: Tubular steel tower analysis - mono-axial stress state and isotropic material Ultimate limit state analysis, analysis of extreme loads Fatigue strength analysis Serviceability analysis, natural frequencies analysis Example: Rotor hub analysis - multi-axial stress state and isotropic material

5 Content XIII Geometric design Ultimate limit state analysis - critical section plane method Fatigue strength analysis - procedure-dependent S/N curves Example: Rotor blades analysis - mono-axial stress state and orthotropic material Concept of admissible strain for analysis of the chords Local component failure Choice of materials and production methods Wind pump systems Characteristic applications Types of wind-driven pumps Operation behaviour of wind pumps Suitable combinations of wind turbines and pumps Qualitative comparison of wind pump systems with piston pump and centrifugal pump Design of wind pump systems Design target Selection of the rated wind speed for the wind pump design Design of a wind pump system with a piston pump Design of a wind pump system with a centrifugal pump Wind turbines for electricity generation - basics The alternator - single-phase AC machine The alternator (dynamo) in stand-alone operation Types of excitation, internal and external pole machine Alternator (single-phase AC machine) in grid-connected operation Three-phase machines The three-phase synchronous machine The three-phase induction machine Power electronic components of wind turbines - converters Supervisory and control systems for wind turbines Methods to manipulate the drive drain Aerodynamic manipulation measures Drive train manipulation using the load Sensors and actuators Controller and control systems Control strategy of a variable-speed wind turbine with a blade pitching system Remarks on controller design

6 XIV Content Annex I Annex II Concepts of electricity generation by wind turbines Grid-connected wind turbines The Danish concept: Directly grid-connected asynchronous generators Directly grid-connected asynchronous generator with dynamic slip control Variable-speed wind turbine with converter and direct voltage intermediate circuit Variable-speed wind turbine with doubly-feeding asynchronous generator and converter in the rotor circuit Power curves and power coefficients of three wind turbine concepts a small comparison Wind turbines for stand-alone operation Battery chargers Resistive heaters with synchronous generators Wind pump system with electrical power transmission Stand-alone wind turbines for insular grids Asynchronous generator operating in an insular grid Wind turbines in isolated grids Wind-diesel system with a flywheel storage Wind-diesel system with a common DC line Wind-diesel-photovoltaic system (minimal grid) Final remark Wind turbine operation at the interconnected grid The interconnected electrical grid Structure of the interconnected electrical grid Operation of the interconnected grid Wind turbines in the interconnected electrical grid Technical requirements of the grid connection Interaction between grid and wind turbine operation - network interaction and grid compatibility Characteristics of wind turbine concepts for grid-connected operation Planning, operation and economics of wind farm projects Wind farm project planning Technical planning aspects Legal aspects of the approval process

7 Content XV Estimation of economic efficiency Erection and operation of wind turbines Technical aspects of erection and operation of wind turbines Legal aspects Economic efficiency of operation Influence of the hub height and wind turbine concept on the yield General estimation of the annual energy yield of an idealised wind turbine Offshore wind farms Offshore environment Offshore design requirements Wind turbines Support structures and marine installation Grid connection and wind farm layout Operation and maintenance Economics

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