7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

1/22

MAXIMIZING BLADE LIFE

1

UWIG Wind Turbine Operations and Maintenance Users

Group Meeting

Sara Agalliu LM Wind Power

April 11, 2012

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

2/22

The extended family

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

3/22

Increased blade-to-tower clearance

Reduced need for blade stiffness

and hence blade weight

Increased swept area

Increased energy production

Further pre-bending advantages

The rotor COG is pushed less forward

Less bending of main shaft

Improved material utilization driving

Cost of Energy

LM Feature Pre-bending

Lighter blades

Larger swept area

Clearance to the tower

Lighter blades

Larger swept area

Clearance to the tower

3

Prebend glas blade.

Carbon blade.

Loaded blade with same tower clearance

Prebend glas blade.

Carbon blade.

Loaded blade with same tower clearance

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

4/22

LM Feature Lightning ProtectionSystems

4

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

5/22

Blades of Tomorrow

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

6/22

Design Life versus Operational Life

Static testing

Fatigue testing

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

7/22

7

Failure Rate

LM has sold approx. 20,000 LM 37.3 P2 blades

As of today,121 have failed approx 0.6%

Most other LM blades is likely to have lower failure rate

Smaller blade types are designed more conservatively

Bigger blades are used in less extreme sites

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

8/22

Why do blades fail?

Mountain ridge

=> turbulence

Lightning strike

into shell

Cold weather

Limited bonding =>

manufacturing deviation

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

9/22

9

Turbine operation

1

2

3

Tower

Nacelle

Handling Transport

Storage - Flood

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

10/22

InspectionsRepairs

Preventative Maintenance

Updating blades with additional features

Getting 20+ years

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

11/22

Inspection of blades

Rotor blades are wear parts

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

12/22

Inspections of blades

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

13/22

Development of damage

Same damage 2 months later

Handling damage

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

14/22

Transport damage

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

15/22

Safety Factors

Repair of a defect will never be as

strong as a reference blade without

defects (reduction factors)

Reduction factors are based on test

and experience

Safety factors must always be above

1.0 after repair

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

16/22

Structural Damages

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

17/22

Field measured mechanical loads

17

Preventative maintenance pays off

Wind speed in m/s

Restored Clean & Smooth Profile

Original Dirty & Rough Profile

Total power return 3-8% per year

Turb

inepoweroutputinM

W

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

18/22

240 min

Rain erosion test

0 min

LEADING EDGE PROTECTION (LEP)

90 min60 min30 min 300 min270 min

No LEP

LE Tape

LE coating

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

19/22

LM Diverter Strips

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

20/22

20

Boosting your performance

Cost efficient up-tower options

to increase AEP exist

Boost package streamlines & pressure contour plots

Vortex generators

maintain attachedflow

Vortex generator flow visualization

Clean surfaceVortex

generators

Flow is separating

without vortexgenerators

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

21/22

KNOW

YOURBLADES...

7/29/2019 UWIG_2012_Sara Agalliu (1).pdf

22/22

QUESTIONS

Together we capture the wind to

power a cleaner worldThe LM Wind Power vision