wind energy new dimensions in metrology

Wind Energy –

New Dimensions in MetrologyThomas Wiedenhöfer, Frank Härtig

of 18

sailing vessels in the

ancient Egypt

ChronologyApplication of wind energy about 1500 BC

windmills in China

photo: Elvira Kronlob source: Carl von Canstein

of 18

Goals for wind energy systems (WES)

• Core environmental and sustainable objectives

- reduction of greenhouse gases

- avoidance of pollution / dangerous waste (coal / nuclear plants)

• Technical and economical objectives

- competitiveness with conventional energy supply

- reliability, safety, reasonable maintenance (lifetime 20 years)

• Political objectives

- secure energy supply (at all weather conditions)

- development of structured grids

- reduction of subsidies and infrastructure costs

Germany: renewable energy sources act2020 35% renewable energy; ( today 25%)

of 18

Development and forecast of WES sizes

1980 1985 1990 1995 2000 2003 2010 2020

50 kW

15 m

100 kW

20 m

500 kW

40 m

600 kW

50 m

2,000 kW

80 m

5,000 kW

126 m

10,000 kW

150 m

20,000 kW

235 m

1980 1985 1990 1995 2000 2003 2010 2020

50 kW

15 m

100 kW

20 m

500 kW

40 m

600 kW

50 m

2,000 kW

80 m

5,000 kW

126 m

10,000 kW

150 m

20,000 kW

235 m

• 3 blade rotors (6

• gear boxes (ratio 1:100)

• pitch controlled blades

• average capacity 2 MW (trend

repowering existing WES)

• expected lifetime 20 years

• typical „big“ systems 5-6 MW

In less than 30 years, the yield from wind turbines has increased more than 500 times

• 3 blade rotors (6-15 rpm)

• gear boxes (ratio 1:100)

•

•

•

Hall of Supreme Harmony

of 18

Components of the WES drive train

source: Bosch-Rexroth

pitch-control

rotor hub

main (rotor)

bearing

main shaft

rotor blade

yaw (azimuth) control

gear box

disk brake

generator

frame

yaw (azimuth) drivetower

source: ENERCON

source: VESTAS

of 18

Failure frequencies and impacts

source: Fraunhofer IWES, Kassel

annual failure frequency downtime per failure in days

drive train

support & housing

generator

gearbox

rotor Blades

mechanical brake

rotor hub

yaw system

hydraulic system

sensors

electronic control

electrical system

1 0.75 0.5 0.25 0 2 4 6 8

annual failure frequency downtime per failure in days

drive train

support & housing

generator

gearbox

rotor Blades

mechanical brake

rotor hub

yaw system

hydraulic system

sensors

electronic control

electrical system

1 0.75 0.5 0.25 0 2 4 6 8

of 18

Cost distribution caused by WES failures ‘09

source: Sensen, Gothaer Allgemeine Versicherung AG

wind rotors

21.1 %

others

9.1 %generators

15.1 %converters

7 %

trans-

formers

7.2 %

other

electrical failures

13.8 %

gear boxes

26.6 %

of 18

Traceability of dimensional and torque measurement

Calibration of torque

PTB: 1100 kN·m (biggest system worldwide)Himmelstein (USA): 450 kN·mSMERI (China): 200 kN·m (biggest system with direct mass)LNE (Frankreich): 200 kN·m

Biggest systems in dimensional metrology:

PTB / NPL / NMIJ, ... : measuring volume < 1m3

problem: no standards > 1m3 available worldwide

problem: systems traceable only up to 1100 kN·m

of 18

Competence Centre “Wind Energy”

5 to 20-MN·m-(torque)

Coordinate Metrology 4m x 5m x 3m

cleaning; acclimatisation

of 18

Calibration of large involute gear artefact

measurements in industry

mover: CMM

environment: measuring room

workpiece: calibrated involute gear artefact

(reference, validation)

Parameter Value

Number of teeth z 38

Normal module mn 20 mm

Pressure angle n 20°

Face width b 400 mm

Helix angle 0°/spur; 10°/R; 20°/L

Outside diameter da 1000 mm

Weight 450 kg (700 kg)

Reference bands

diameter (form deviation)

200 mm (1 µm)

Calibration for gear measurement today

of 18

3D-Abbe principle – task specific correction

1st step – real measurement

measure workpiece

use CMM and application software

register spatial locations

in machine coordinates (x, y, z)

export of all probing points

from the application program

Cartesian CMM (not Abbe error free)

Concept for precise coordinate

measurement of big work pieces 1/4

of 18

3D-Abbe principle – task specific correction

2nd step – 3D-Abbe measurement

remove workpiece

exchange stylus by triple reflector

approximately at same centres

Cat-Eye

working range 120°

n=2-ball

working range 160°

align at least 4 tracking interferometers

move to all measurement points

measured in step 1

synchronised read out of all tracking interferometer

3D Abbe error free

measurement for

measurements

on Cartesian CMMs



of 18

3rd step – evaluate the local error vector and

correct mover points

Mover position during measuring

M3D3 coordinates during error mapping

Error vector

Mover position indicated during error mapping

Correctedmover position



of 18

Calibraition of large involute gear artefactConcept for precise coordinate


of 18

Calibration of torque 5 MNm to 20 MNmpart under test

of 18

conventional LIDAR new – LIDAR calibration system

to be calibrated Measurement height: 10m – 200m

measuring mast free

MU: 0,1 m/s; spatial resolution: 10-9 m3

Third part of CC-Wind: Wind-Lidar

of 18

Clues for further development and needs

source: Fraunhofer IEWSsource: Fraunhofer IEWS

http://strom-report.de/

offshore

employment

systems

capacity

Onshore Germany

of 18

Physikalisch-Technische Bundesanstalt

Braunschweig and Berlin

Bundesallee 100

38116 Braunschweig

Thomas Wiedenhöfer (Wiedenhoefer)

Telefon: +49 (0)531 592-1189

E-Mail: [email protected]

Thank you for your kind attention

wind energy new dimensions in metrology

Documents