PPT-0621 Rev WTG dynamics in soft & stiff towers beyond ... · • Company Introduction • Nabralift ... [MNm] Time [s] Bending Moment @ Tower Bottom Soft-Stiff Soft-Soft 0 0.5 1

BREMEN29th August, 2017

CRISTINA GARCÍA PÉREZION AROCENA DE LA RÚAwww.nabrawind.com

WTG Dynamics in Soft & Stiff Towers Beyond 160m Hub Height

2

CONTENTS

1. Nabralift® Self-Erecting Tower• Company Introduction• Nabralift® Description• 1st Commercial Product• Nabralift® vs Market Challenges

2. Soft vs Stiff XXL Tower Dynamics• Analysis Introduction• Results for Critical Loadcases• Results Summary• Summary of Results and Conclusions

3

1 Nabralift® Self-Erecting TowerCompany Introduction

NABRAWIND TECHNOLOGIESAdvanced Wind Technologies

Modular Blade Joint

Self Erected Tower

Drastic Cost Reduction

Modularity Proven Technologies

4

1 Nabralift® Self-Erecting TowerCompany Introduction – Scope of Activities

Design Adaptation

Specific MBJ/SET Design

Turnkey Delivery

MBJ/SET Components Manufacturing

WTG Load Analysis

WTG Variant Certification

Blade Design Adaptation

WTG Self Erection

5

1 Nabralift® Self-Erecting TowerProduct Description

Tower Transition

Lattice Modules

Foundation

6

1 Nabralift® Self-Erecting TowerProduct Description

7

1 Nabralift® Self-Erecting TowerTower Assembly and WTG Self Erection

Conventional WTGLarge Cranes

NabraliftSmall Cranes for WTG Assy Nabralift Self-Erection

130-170 Boom750-1600T Cranes

70-80 Boom500-600T Cranes

NabraliftSelf Erection System

8

3 NABRALIFT®

Product Description

9

1 Nabralift® Self-Erecting TowerTower Maintenance

Blade Tip Repair Platform

O&M CraneMaintenance Free Tower Segments• Tower Components• Bolted Connections

10

Component Certificate

1 Nabralift® Self-Erecting TowerCertification & Prototypes Status

2016 2017 2018

DesignFull Scale Test

1st Commercial Product• 160m Hub Height

• 125-140m Diameter

• 3.3-3.6MW Range Design Loads

Manufacturing Assy

Design Certificate

1st Wind Farms

11

1 Nabralift® Self-Erecting TowerXL Market Challenges

-20/25%

+20/30m

-4/5%

Cost Increase€HH140=1.6·€HH100

Most Expensive Component HH>120

12

1 Nabralift® Self-Erecting TowerXL Market Challenges

Cost Increase€HH140=1.6·€HH100

Most Expensive Component HH>120

WTG IntegrationControl Challenges in Soft-Soft TowersSoft-Stiff Unfeasible for XL Steel Towers

LogisticsRoads / Bridges Limiting Concepts

InstallationXL Cranes Driving Installation CostExpensive Mobilization and Rental

OperationLarge Correctives OPEX Increase

unfeasibleor

extra-stiffened specific control

lownoise?

13

CONTENTS

1. Nabralift® Self-Erecting Tower• Company Introduction• Nabralift® Description• 1st Commercial Product• Nabralift® vs Market Challenges

2. Soft vs Stiff XXL Tower Dynamics• Analysis Introduction• Results for Critical Loadcases• Results Summary• Summary of Results and Conclusions

14

2 Soft vs Stiff XXL Tower DynamicsAnalysis Introduction – Tower Models

Soft-Soft Soft-StiffHub Height 160m 160m

Technology Monotubular Nabralift®

1st Mode Freq. 0.16 0.23 Hz

Tower Top Defl. (1MN) 3.80 1.77 m

Tower Mass 620 450 T

15

2 Soft vs Stiff XXL Tower DynamicsAnalysis Introduction – Tower Models

0

0.1

0.2

0.3

0.4

0.5

0.6

0.0 2.0 4.0 6.0 8.0 10.0 12.0

Freq

uenc

y [H

z]

Rotor Speed [rpm]

Campbell Diagram1P 3P Minimum SpeedNominal Speed Soft-Stiff 1st Mode Soft-Soft 1st Mode

16

2 Soft vs Stiff XXL Tower DynamicsAnalysis Introduction - Loadcases

Case A: 1.2 Power Production

Case B: 2.4 Power Production + Fault

Case C: 6.4 Idling

>400 loadcases fatigue>2000 loadcases ultimate

17

Wind

Bending Moment - My

X-DeflectionWind

Bending Moment - My

X-Deflection

x

z

y x

z

y

2 Soft vs Stiff XXL Tower DynamicsResults

Wind

Bending Moment - My

Wind

Bending Moment - Myx

z

y x

z

y

18

0

10

20

30

40

50

60

Soft-Stiff Soft-Soft

My

[MNm

]

Fatigue Equivalent Bending Moment @ Tower BottomFLS

+9%

0

20

40

60

80

100

120


My

[MNm

]

Maximum Static Bending Moment @ Tower BottomULS

+8%

Case A – 1.2 Power Production

40

50

60

70

80

90

100

110

0 20 40 60 80 100 120 140 160 180 200

My

[MN

m]

Time [s]

Bending Moment @ Tower BottomSoft-Stiff Soft-Soft

0

0.5

1

1.5

2

2.5

3

0 20 40 60 80 100 120 140 160 180 200

X-D

efle

ctio

n [m

]

Time [s]

Tower X-deflection @ Tower TopSoft-Stiff Soft-Soft

4

6

8

10

12

14

16

18

0 20 40 60 80 100 120 140 160 180 200

Hub

win

d sp

eed

mag

nitu

de [

m/s

]

Time [s]

TurbulentWindSpeed Wind

Bending Moment - My

X-Deflection

Wind

Bending Moment - My

X-Deflection2 Soft vs Stiff XXL Tower DynamicsResults

19

0

50

100

150

200

250


My

[MNm

]


+51%

-200

-150

-100

-50

0

50

100

150

0 50 100 150 200 250 300 350 400

My

[MNm

]

Time [s]


-5

-4

-3

-2

-1

0

1

2

3

0 50 100 150 200 250 300 350 400

X-D

efle

ctio

n [m

]

Time [s]


4

6

8

10

12

14

16

18

0 50 100 150 200 250 300 350 400

Hub

win

d sp

eed

mag

nitu

de [m

/s]

Time [s]

TurbulentWindSpeed2 Soft vs Stiff XXL Tower DynamicsResults

Case B – 2.4 Power Production plus Occurrence of Fault

Wind

Bending Moment - My

X-Deflection

Wind

Bending Moment - My

X-Deflection

020406080100120140160180


My

[MNm

]


+28%

20

0

10

20

30

40

50


My

[MNm

]


0%

0

10

20

30

40

50

60


My

[MNm

]


+1%

-10

0

10

20

30

40

50

60

0 20 40 60 80 100 120 140 160 180 200

My

[MNm

]

Time [s]


-0,2

0

0,2

0,4

0,6

0,8

1

0 20 40 60 80 100 120 140 160 180 200

X-D

efle

ctio

n [m

]

Time [s]


15

20

25

30

35

40

45

0 20 40 60 80 100 120 140 160 180 200

Hub

win

d sp

eed

mag

nitu

de [m

/s]

Time [s]

TurbulentWindSpeed2 Soft vs Stiff XXL Tower DynamicsResults

Case C – 6.4 Idling

Wind

Bending Moment - My

X-Deflection

Wind

Bending Moment - My

X-Deflection

21

0

10

20

30

40

50

60


My

[MNm

]


+20%

0

20

40

60

80

100

120

140

160


My

[MNm

]


+12%

2 Soft vs Stiff XXL Tower DynamicsGlobal Results

22

2 Soft vs Stiff XXL Tower DynamicsSummary of Results and Conclusions

• An IEC-Compliant Load Analysis has been completed for:• A wind turbine of 3.5MW with a 160m tall soft-soft tower, a rotor diameter of 130m and a

overall nacelle weight of 200T.

• A wind turbine of 3.5MW with a 160m tall soft-stiff tower, a rotor diameter of 130m and a overall nacelle weight of 200T.

• Tower flexibility increases static and fatigue loads:• Moderate increase in WTG Operation• Significant increase in Shut Down loadcases (critical for soft-soft towers)

Summary of Results and Conclusions

Thanks for your Attention

Documents

PPT-0621 Rev WTG dynamics in soft & stiff towers beyond ... · • Company Introduction • Nabralift ... [MNm] Time [s] Bending Moment @ Tower Bottom Soft-Stiff Soft-Soft 0 0.5 1