Wind Energy, - 캐드앤그래픽스 · PDF fileWind Energy, Engineering Services ... Level...
Transcript of Wind Energy, - 캐드앤그래픽스 · PDF fileWind Energy, Engineering Services ... Level...
Wind Energy,
Engineering Services and Software Solutions for System
Level Simulation from among Wind Turbine Simulation
이혁재 과장MSC Korea 2009
Agenda
• Engineering Challenges for Wind Turbine Manufacturers
• Simulation of Wind Turbine using MBS
• Reference
7/30/2009 2
Trends
• Increase of power generated per WT
• Result: Growing size
Engineering challenges
• Reliability vs. reduction of “Top Head” mass
E.g. relative gear box weight down, failure rates up
Growing size increasing structural elasticity/flexibility
• Acoustic performance (noise reduction)
• Maximum efficiency and aerodynamic performance
Also at low wind speeds
• Offshore expansion
Wind Turbine Trends & Engineering Challenges
3
0
20
40
60
80
100
120
140
160
1980 1985 1990 1995 2000 2005 20101980 1985 1990 1995 2000 2005 2010
50kW 300kW
500kW600kW
1.5MW
2.5MW
6.5MW
10MW?
160
140
120
100
80
60
40
20
0
Ro
tor
Dia
mete
r
• Limitations of physical tests
Size of equipment (rotor blades, tower, …) limits number of available test facilities
Control over loads
(weather / wind conditions)
Expensive, slow, late
in development cycle
Limited understanding of durability
issues
• Simulation advantages
Accelerate time to market
Allows prediction of durability issues
Increasing system reliability
Decreasing warranty and maintenance
expenses
Virtual tests against various weather
(wind, off-shore: waves) conditions
System size not an issue
Value of Simulation
4
Process for Design Evaluation
5
Type Certification according to IEC WT01
Design Evaluation
Safety System
Rotor Blades
Electrical Components
Personal Safety
Nacelle / Spinner
Loads
Mechanical
Components
Tower
Foundation &
Bases
Manuals (maintenance,
manufacturing, commissioning)
Process for Design Evaluation
6
Process for Design Evaluation
7
Process for Design Evaluation (Cont.)
8
IEC/Specified
StandardAerodynamic
Detail Design
1. Dynamic
2. Composite
3. Fluid
…Control
1. C, Fotran etc
2. Simulink or Easy 5Fatigue
Analysis
Load Calculation
Extreme/Fatigue
Load Extract
System Modeling
(Parameterized)
Force & Moment
Vibration
Extreme Load
Fatigue Load
FE Analysis
System Simulation
Structure Simulation
Simulation of Wind Turbine using MBS
7/30/2009
• Adams is a very flexible software for general mechanical system simulation
• Applied on wind turbines, detailed models can be created including gear
boxes, control systems, bearings, etc
• Adams has been used for wind turbine simulations for more than 10 years
• Static analysis, dynamic analysis and frequency domain analysis
Complete Wind Turbine Simulation
Aerodynamics
Control systems
Hydraulics
Electric systems
Flexible bodies
Roller bearings
Gears
Linearization
Frequency
domain analysis
Transient analysis
System performance
Load histories
Disp / Vel / Acc
Stress recovery
10
Gear Modeling ; Subsystem Level
• Idealized constraints
The most simple approach
Add gear ratio between axles
No back lash
• Simplified gear contact
Analytical contact calculation, based on true gear
geometry
Very fast to simulate
Spur gears, helical gears, bevel gears, planetary gears
Takes back lash into account
Load investigation of shafts and bearings
Study of gear rattle and general system behavior due to
lash and losses in gears
Incre
ased
accura
cy
11
Gear Modeling (Cont.) ; Subsystem Level
• Detailed 3D contact
Generates accurate gear geometry in Adams
3D contact between rigid gears
Load investigation of gears, shafts and
bearings
Study of gear rattle and general system
behavior due to lash and losses in gears
Friction in tooth contact
Incre
ased
accura
cy
• Flexible gear contact
Uses Nastran as pre-processor to generate accurate data for
flexible tooth contact in Adams
High level of detail, takes local tooth flexibility into account
12
Geartrain System Simulation ; Subsystem Level
Options in MD Adams
• Kinematic coupling
• GearTrain toolkit*
• User defined subroutines
13
Business: Manual transmissions, transaxles, driveline products
Challenge: Eliminate gear noise problems
Solution: Using Adams to investigate rattle generation in early stages of design, before any hardware is built
Value: Simulation saves tens of $K and months of development effort, and improves designs
“Predictive engineering is key to optimizing designs early in the development cycle. We can test and fix designs in the computer so we get it right before any parts are built.”
-- Bob Perkins Manager of Engineering Systems
Case Study – New Venture Gear
14
Bearing Modeling ; Subsystem Level
• Linear six component spring-damper
• Non-linear six-component force
• Detailed ball/roller bearing model
Takes local flexibility into account
Outer ring is rigid, doesn’t take gearbox flexibility into account
Nastran is used as preprocessor to generate bearing data for Adams
Picture below shows ball bearing but roller bearing is also available
Incre
ased
accura
cy
15
Bearing Modeling ; Subsystem Level
MD Nastran
• Statics
• Dynamics
• 2D / 3D Contacts
• Thermal
• Common data model
Department interoperability
Cost and time savings
• Combined nonlinearity
Geometric & material
• Glueing
• Friction
Incl. heat generation
7/30/2009 16
MD Adams
• Kinematic coupling
• Compliances
Linear
Nonlinear
User-defined subroutines
• Rolling bearing toolkit*
Automated design process
Contact force model
Finest FE-meshes
Fast contact simulation
Fast system simulation
• Flexible bearing contact
Bearing Modeling, continued ; Subsystem Level
17
Brake Systems ; Subsystem Level
• Rigid disc
Model as torque applied to shaft
User defines brake torque magnitude based on any state in the model,
for example angular velocity of shaft, pitch angles, etc
Can also include PID controller
• Flexible disc
High fidelity model, can be used for analysis of brake squeal and other
vibration-related problems
• Import Control System from Control Design Code (Easy5 or MATLAB/Simulink)
Detailed models can be imported into Adams and connected to the
mechanical model
Preserves investments already made in Control Design Code
Typical approach is to import control system from Control Design Code
that sets a torque in the Adams model
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Case Study:
Bosch Brake Systems
Business: Second largest supplier of automotive technology worldwide
Challenge:Assess the influence of design parameters on the brake assembly’s dynamic response, including thermal effects
Solution:Modal force element in Adams, which captures the thermal deformation calculated with MSC.NASTRAN.
Value: Reduced the need for physical prototypes through increased accuracy of virtual approach
“Thermal deformations can readily be included through modal force definitions which lead to an accurate component response. A significant system influences can be noted”
-- Richard A. Swift, Ph.D, BOSCH Automotive Corporation
19
2009-07-30 20
ADAMS WindTurbine Toolkit ; System Level
• ADAMS WindTurbine Toolkit has been developed under contract to the National Renewable Energy Laboratory (NREL) specifically for modeling horizontal-axis wind turbines
• ADAMS WindTurbine Toolkit can be thought of as an “overlay” for ADAMS/View
• ADAMS WindTurbine Toolkit gives the user greater confidence in his model’s fidelity by automating the turbine modeling process
• This tool is used for:
Calculating loads for fatigue analysis
Estimate torques in power train
Verifying system dynamics
Etc
• There are 2 different types of ADAMS WindTurbine Toolkit:
ADAMS/WT 2.0
ADAMS/Adwimo
Flexible blades
Flexible tower
Aerodynamic forces
applied on blades
Power train
with generator
• Flexible rotor blades
• Flexible tower, can be supported by wires
• Aerodynamic forces on blades
• Detailed aerodynamic model, includes turbulence, wind shear and tower shadow
• Rather simple power train model
• Rigid hub with flexible connection to blades
Common modeling• Aerodynamic forces act at a point
• Smooth load distribution by nastran
• NREL / Aerodyn
• Certified by Germanischer Lloyd
• ADAMS open SW-architecture
• User subroutines (C,FORTRAN)
• Large number of utilities
Adv. aerodynamic modeling• Distributed aerodyn. pressure
• On-going research
Blade modelling - Aerodynamics
2009-07-30 21
22
ADAMS/WT 2.0 Toolkit ; System Level
• ADAMS/WT 2.0 can select,
the direction of rotor rotation and whether
the rotor is an upwind or downwind config.
• Straight, tapered flexible beam
Untwisted version of flexible rotor blade element
Optionally, add sets of guy wires
• Input for tower:
Mass/unit length, Section mass moments of inertia, Section CG offsets from reference axis
Structural twist, Torsional stiffness, Lateral stiffness, Extensional stiffness
2009-07-30 22
FIELD
element
Part
boundary
2009-07-30 23
• Straight, rigid blade plus flapping hinge (Including Lumped masses, beams elements)
• Input for rotor blades:
Mass/unit length, Section mass moments of inertia, Section CG offsets from reference axis
Structural twist, Torsional stiffness, Lateral stiffness, Extensional stiffness
• Aerodynamic forces on blades
Simple model
CL = dCL/da * a
CD = CD0
Advanced model
AeroDyn routine, developed by University of Utah
Takes into account turbulence, wind shear, tower shadow
ADAMS/WT 2.0 Toolkit ; System Level
Hinge
2009-07-30 24
• Four types of rigid rotor hubs, with flexible connections to blades
Hub flexibility
It’s add flexible BUSHING elements between the dummy PARTs at the blade
attachment markers and the hub itself
ADAMS/WT 2.0 Toolkit ; System Level
2009-07-30 25
Aero dynamic loads
• AeroDyn fully integrated with Adams
AeroDyn is an aerodynamics software library for use by designers of horizontal-axis
wind turbines
The aerodynamics model in AeroDyn is a detailed analysis that includes blade-
element/momentum theory (with modifications to improve accuracy in yawed flow),
dynamic stall, and an optional dynamic inflow theory
Includes full-field turbulence wind model
AeroDyn is maintained by National Renewable Energy Laboratory (NREL) in the US
• Adams’ open architecture allows other codes to be added
2009-07-30 26
• Rather simple power train model
• Idealized gearbox with gear ratio
• Flexible shafts (rotational stiffness only)
• Induction-Type Motor-Generator
Thevenin’s Equation or Functional Definition
ADAMS/WT 2.0 Toolkit ; System Level
Modeling
• Easier-to-use
• Parametrics
• Aerodynamics
NREL/AERODYN
User-defined
Simulation
• Batch
ADAMS/WT 2.0 Toolkit Simulation ; System Level
27
Control systems
• Simple controllers (PID) can be created directly in Adams
• For more advanced controllers, MATLAB/Simulink and Easy5 models can be
imported into Adams
• Adams solves the fully coupled control+mechanical system
• Typical applications are pitch control, yaw control, brake system, pitch control
hydraulics, etcAdams
Simulink
Easy5
28
Case Study
MOOG JAPAN LTD
Business:General Machine, Wind Turbines
Challenge:Introduction of Servo actuator simulation by
using Easy5
Solution:A simulation example of the pitch control servo
actuator for wind-power generation system was performed using Easy5
Value:Simulation was performed with a typical hydraulic circuit and differential hydraulic circuit. The cause of the difference with simulation is being studied.
Case Study
Servo Valve(var area gradient)
Upstream BoundaryConditions (P, T)
P = 250
T = 50
Global FluidProperties
HydraulicFluid
8
2 Chamber Actuatorw position input
Split S->RS Fixed orifice
Single Mass(hard limits & friction)
-1
1
SaturationFunction
-100
100Gain=1
100
Gain Block
Constant pressure source
I_SV
Check ValveS->R (P)
Check ValveS->R (P)
IDIFF
Two tabularfunctions of time
REF
POS
Merge SSS->R
Merge SSS->R
Check ValveS->R (P)
Split w/orifices S->RR (P)
Check ValveS->R (P)
Merge SSS->R
CV_PILOT_PCV_PILOT_P
Check ValveS->R (P)
Check ValveS->R (P)
Split w/orifices S->RR (P)
CV_PILOT_PCV_PILOT_P
Fixed orifice
Adiabatic AccumulatorGas-charged
AdiabaticVolume (P)
wind_ACTR(6)
29
• To assemble a full parametrik windturbine you need the mnf files and some informations(initial setup, information about node ids)
conceptual design
• You can start a simulation without aerodyn forces, there is a initial velocity on the hub
• Running the simulation (with Multi Analyse)
ADAMS/Adwimo Toolkit Modeling Steps ; System Level
FREC. : 0.45 Hz
DAMPING : 0.36%
FREC. : 5.04 Hz
DAMPING : 1.6%FREC. : 44 Hz
DAMPING : 1.03%
ADAMS/Adwimo Toolkit Modeling Steps ; System Level
• Change the parameters to
get a new design,
such as tilt angle, cone angle,
overhang, initial pitch angle….
• Add a gearbox from a predefined library,
or add your own to the library
• Complete your windturbine
with aeroforces time dependent forces
and aerodyn (dev. by NREL) forces are
embedded and finish your setup
with the definition of a controller
ADAMS/Adwimo Toolkit Modeling Steps ; System Level
• Simulate your windturbine, either in a single interactive mode, or in a batch mode with different wind input file, or use the full power of Adams/View and Adams/Insight to study the design
• Import your existing FAST (dev by NREL) model,
and update the model with flexible in one step
ADAMS/Adwimo Toolkit with Flexible body simulation
• Discrete flexibility (ADAMS/WT 2.0)
Masses connected with beam elements
Will capture stiffening effects due to
rotation, gyroscopic effects, etc
Typically used for wind turbine blades
• Modal flexibility (ADAMS/Adwimo)
Import flexible body from FEA
Nastran, Marc, Abaqus, Ansys, I-DEAS
Craig-Bampton modes exported to
Adams
Represents linear elastic flexible body
Modal stress recovery
FEA MBS
Modal
reduction
• Single modeling procedure• Conceptual design
• Beams & masses
• Finite element models (isotropic)
• Detailed design phase• Real-life finite element models
• Isotropic & composites
• Multiple design objectives
• Wind turbine dynamics
• Stress design
• Single enterprise model
• Benefits• Shorter simulation cycles
• Faster virtual testing
MSR
CADFEpre
FEmesh
FEA(k,m) K,M
MBD
F, MFE
statics
σ-ply
q(t)
Blade Modeling with Flexible Bodies
ADAMS Flexible Bodies
• ADAMS/Durability• Features stress display
• Hotspot identification
• Output to durability SW
• NASTRAN stress recovery
• FE-postprocessors
• Composite design tools
• Loading effects considered• Aerodynamic forces
• Gravity
• Centrifugal forces
• Coriolis acceleration
• Gyroscopic moments
• Point loads
• Joints, springs, etc.
• Thermal loads
2009-07-30 36
Design Point Analyze for Complex Subsystem(Using Multi-Body Dynamic)
Linearization
• Large library of modeling elements
• Accurate handling of constraints:
– Time dependencies
• Frequency domain analysis with the linear model
Mode
Frequency, Hz at rotor speed of
0 rpm 660 rpm
Exper. Nastran ADAMS Exper. Nastran ADAMS
1st flap 10.7 11.53 11.53 28.8 29.62 29.84
2nd flap 32.6 36.38 36.36 51.75 55.69 55.73
1st chord 41.0 42.44 42.41 49.1 49.1 49.38
3rd flap 67.8 76.80 76.77 91.5 96.52 96.38
1st torsion 110.3 102.05 102.05 115.0 102.53 102.33
Mode
Frequency (rad/s)
ADAMS RCAS
1 1.178 1.186
2 1.256 1.271
3 2.690 2.765
4 5.164 5.415
5 7.923 7.944
Rotating flexible non-uniform helicopter blade
• Plotting and visualization of response
• Linearization at any operating point
• All inertial effects included:
Gyroscopic, Coriolis, . . .
Offshore wind turbine
Variable cross section helicopter blade from NASA
paper: NASA Technical Memorandum 4760. W. Keats et al. 1997
Paper has numerical results (MSC.Nastran) and experimental
results
MSC.Nastran input deck was used to generate 20 subsystems
imported into ADAMS and stitched using fixed joints
Model was spin to operating velocity and linearizations
performed
Rotor radius 63.5m
Model exported from RCAS to Adams
Good agreement for frequencies w=0, 5, and 15 rad/s
Table shows results for w=5 rad/s
(RCAS is a FEM-based tool for wind turbine simulation,
NREL
Modeling
• User-friendly GUI
• Parametrics
• Generic
• Aerodynamics
NREL/AERODYN
User-defined
ADAMS/Adwimo Toolkit Simulation ; System Level
37
Simulation
• Interactive
• Batch
38
ADAMS/Adwimo Toolkit Simulation ; System Level
Postprocessing
• Numerous interfaces (MD Nastran, MSC.Fatigue, spreadsheet, etc.)
• Graphing + advanced animation features
39
ADAMS/Adwimo Toolkit Simulation ; System Level
Reference, Wind Turbine Industry
7/30/2009 40
• Cener: Adams, Nastran, Patran, Marc, MSC.Fatigue
• NREL: Adams
• Windward Engineering: Adams
• Global Energy Concepts: Adams
• GE Research: Adams
• Gamesa Eólica: Patran & MSC.Nastran
• Ecotecnia: FE-Fatigue
• M-Torres: MSC.Marc, MSC.Mentat, MSC.Fatigue
• Acciona: MSC.Fatigue, Nastran, Patran, Marc
• Mitsubishi Heavy Industries: Adams
• Moog Japan Ltd: Easy5
• Risoe Wind Energy: Patran, Nastran, Marc
• Sandia National Laboratories: Adams, Nastran, Patran
• Matrix/ A.H. Gears/ Windflow Ltd: MSC.Fatigue, Nastran, Patran
• VTT Technical Research Center: Adams
• Center for Wind Energy Research: Adams, Nastran
• NTN: Adams
• Enercon: Patran, Nastran
• Suzlon: Marc, Mentat
• LM Glasfiber: Patran Laminate Modeler
• Kungliga Tekniska Bögskolan: Marc
QnA
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Thank you!