Transcript Folie 1

Load Assumptions for the Design of
electro mechanic Pitch Systems
Andreas Manjock
Germanischer Lloyd Industrial Services GmbH, Business Segment Wind Energy
[email protected], www.gl-group.com/glwind
Load Assumptions for the Design of
electro mechanic Pitch Systems
1. Design of electro mechanic Pitch System
2. Simulation Model
3. Design Load Cases (DLCs)
4. Data Postprocessing
5. Conclusion and Outlook
Source: ENERCON
EWEC 2007
No. 2
1.1 Pitch System Components
Blade Bearing
Rotor Blade
Gear Box
Drive Motor
Symbol Definition
iPD
iPB
JPD
Control Unit
JRB
Pitch
Controller
JPD
Moment of Inertia,
Pitch Motor
JRB
Moment of Inertia,
Rotor Blade
iPD
Ratio of Pitch Drive
Gearbox
iPB
Ratio of Pitch Bearing
Mesh
iP
Ratio of entire
Pitch System
iP
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Load Assumptions for the Design of
electro mechanic Pitch Systems
1. Design of electro mechanic Pitch System
2. Simulation Model
2.1
2.2
2.3
2.4
2.5
2.6
Load Components
System Model
Local Model for Mesh Moment
Drive Motor Characteristics
Drive Motor Limitations
Drive Control Scheme
3. Design Load Cases (DLCs)
4. Data Postprocessing
5. Conclusion and Outlook
EWEC 2007
Source: ENERCON
No. 4
2.1 Load Components
αP
Blade Root Coordinate System
M ZB
MZB
M YB
FY B
F ZB
ZB
YB
M XB
XB
FXB
MR
Symbol Definition
αP
Pitch Angle
MPDA
Pitch Drive Actuator Torque
MZB
Pitch Torque Rotor Blade
MR
Friction Torque Blade Bearing
MPDA
XB in direction of the rotor axis
Z B radially
MR = M0 + µbend∙ Mres+ µaxial∙ Faxial+ µradial∙ Fradial
YB so that XB, YB, ZB rotate clockwise
Source: GL „Guideline for the Certification of Wind Turbines“, 2003
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2.2 System Model
Structural Model
Global Simulation Model
αP
i P•M PDA
M ZB
JPD •i P2• α P**
JRB • α P**
MR
i P2•JPD +J RB
Source: GH Bladed 3.67
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2.3 Local Model for Mesh Moment
Local MM - Assumption“
αP
αP
i P•M PDA
M M •M M
M ZB
JPD •i P2• α P**
JRB •α P**
MR
i P2•JPD
Mass System Pitch Drive
MM = MZB+ JRB ∙ αP** - MR
EWEC 2007
+J RB
Mass System Rotor Blade
Split of Mass System provides
Loads for Drive Train Components
No. 7
2.4 Drive Motor Characteristics
Drive Motor
iP  P
MPDA
Control Unit
Pitch
Controller
Source: OAT Osterholz Antriebstechnik GmbH
EWEC 2007
No. 8
2.5 Drive Motor Limitations
Source: OAT Osterholz Antriebstechnik GmbH
EWEC 2007
No. 9
2.6 Drive Motor Control Scheme
Pitch
Controller
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No. 10
Load Assumptions for the Design of
electro mechanic Pitch Systems
1. Design of electro mechanic Pitch System
2. Simulation Model
3. Design Load Cases (DLCs)
3.1 Identified Load Cases
3.2 Fatigue DLCs
3.3 Extreme DLCs
4. Data Postprocessing
5. Conclusion and Outlook
EWEC 2007
Source: ENERCON
No. 11
3.2 Identified Load Cases
Fatigue Load Cases
EWEC 2007
DLC1.2
Wind
1
2
m/s
57.0%
2
5
m/s
3
7
4
Extreme Load Cases
Turbulence
State
Load Case
Wind
Gust Type
idling
DLC1.5
12 m/s
EOG1
Grid Loss
30.0%
power production
DLC1.6
25 m/s
EOG50
Active Safety Syst.
m/s
24.9%
power production
DLC2.2
25 m/s
constant
Pitch Runaway
9
m/s
22.0%
power production
5
11
m/s
20.2%
power production
6
13
m/s
18.9%
power production
7
15
m/s
18.0%
power production
8
17
m/s
17.3%
power production
9
19
m/s
16.7%
power production
10
21
m/s
16.3%
power production
11
23
m/s
15.9%
power production
12
25
m/s
15.6%
power production
13
28
m/s
15.2%
idling
No. 12
Event
3.3 Fatigue DLCs
Control Variables
EWEC 2007
Load Variables
No. 13
3.4 Extreme DLCs
Control Variables
EWEC 2007
Load Variables
No. 14
Load Assumptions for the Design of
electro mechanic Pitch Systems
1. Design of electro mechanic Pitch System
2. Simulation Model
3. Design Load Cases (DLCs)
4. Data Postprocessing
4.1
4.2
4.3
4.4
Design Driver
Loads for Drive Motor
Loads for Gearbox
Loads for Blade Bearing Mesh
5. Conclusion and Outlook
EWEC 2007
Source: ENERCON
No. 15
4.1 Design Driver
Pitch System Component
Type of Load
Drive Motor
MPDA - Pitch Actuator Torque
αP* - Speed of Pitch Actuator
RMS(MPDA ) - Thermal Loading
Gearbox
LDD of MM - Mesh Torque
(Load Duration Distribution)
Mesh of Blade
Bearing
LDD of MM - Mesh Torque
Distribution of MM vs. αP
(Pitch Angle Duration Distribution)
EWEC 2007
No. 16
4.2.1 Loads for Drive Motor
• Operation States of Drive Motor, Confirmation of global Wind Turbine Simulation
EWEC 2007
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4.2.2 Thermal Loads for Drive Motor
• Standard Deviation (RMS) of pitch actuator torque for thermal impact
• Efficiency of gear box and has to be considered
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normales
Lagerreibmoment
Normal bearing
friction
EWEC 2007
/s
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M PDArms [Nm]
Thermische Belastung des Pitchantrieb
erhöhtes
Lagerreibmoment
Increased bearing
friction (+50%)
No. 18
4.3 Loads for Gearbox
• Load Duration Distribution counting for Mesh Torque M_M
• Influence of Blade Bearing Friction Level comparatively low
Load Duration Distribution of Mesh Torque M_M, Variation of Blade Bearing Friction Level
Duration
No Friction
M_M > 0
High Friction
1
2
3
4
5
6
7
8
9
10
11
12
Load Level Mesh Torque M_M
EWEC 2007
Low Friction
Medium Friction
M_M < 0
No. 19
13
14
4.4 Loads for Blade Bearing Mesh
• Load Duration Distribution counting for Mesh Torque M_M
• Pitch Angle Duration Distribution counting
EWEC 2007
No. 20
Load Assumptions for the Design of
electro mechanic Pitch Systems
1. Design of electro mechanic Pitch System
2. Simulation Model
3. Design Load Cases (DLCs)
4. Data Postprocessing
5. Conclusion and Outlook
Source: ENERCON
EWEC 2007
No. 21
5 Conclusion and Outlook
•
Aerodynamic pitch Moment MZB is not sufficient for the
design of pitch systems drive train
Pitch Actuator Torque is inevitable
•
Blade bearing friction model included in the global
simulation model
•
Integration of drive control unit into the global
simulation model, e.g. limitations in speed and torque
of pitch drive actuator
•
80% damage within first 20°- 25° of blade bearing mesh
•
Measurements on drive trains of pitch systems to
validate MM-assumption
EWEC 2007
No. 22
Keep in Contact
Andreas Manjock
Germanischer Lloyd Industrial Services
[email protected], www.gl-group.com/glwind
EWEC 2007
No. 23