advanced wind turbine controls input based on realtime loads measured with fiber optical sensors...

Advanced Wind Turbine Controls Input Based on RealTime Loads Measured with Fiber Optical Sensors

Embedded in Rotor Blades

ewec 2006, Athens28 February

S. Kuhnt, J. Wernicke, R. Byars, J. Shadden (WindForce GmbH)

Main Issues on Wind Power Plants

• High Operational and Maintenance Costs• Reliability below Customer Expectation

– MTBF, MTTR

• Competitiveness of COE• Low Insurability• Rapid Market Development

FIBRADAPT™Advanced Wind Turbine Control System

Goal• Reduction of Structural

and Dynamic Loads (extreme and fatigue)

• Increasing the Lifetime of Wind Turbine Components

• Component Reliability Improvements (MTBF, MTTR)

• Project Controlling and Management Parameter

• Fast Return on Investment (ROI)

Investments in Innovation ensure Future Business Opportunities

Operational Conditions of a wind turbine

• Measuring of Rotor flapwise and edgewise Loads and Frequencies during Operation

• Traceability of single Events (extreme Loads, emergency Stop etc.)

• Traceability of fatigue Loads for residual Lifetime Estimation

• Monitoring of Design Parameter• Monitoring of the Component Structure for early Detection

of Damages and for determining predictive Maintenance

Targets

Installed Measurement System

Fibre Bragg Grating (FBG) -Benefits

• Multiple sensors in a single Fibre– Simple Connectivity, low Sensor Mass

• No EMI with other operational Systems • Higher Measurement Quality and Stability

– Solid state Electronics – Lifetime Operation

• High Reliability of Sensors

No EMI, no Corrosion, high Reliability

Control Interface Electronics

Specification Value

Range +/- 4000 microstrain range

Resolution 0.8 microstrain

Repeatability (short term) +/- 5 microstrain

Repeatability (long term) +/- 10 microstrain

No of Sensors 100 per channel

Maximum sensor distance > 2 km

Scan Frequency 25 Hz for 20 Sensors

Power Requirement 12 V @ 0.25 A Typical (3W-12Wl)

Interface Ethernet, CANBus, RS422 etc.

FIBRADAPT: Advanced wind turbine controls

Residual Lifetime Estimation

Residual Lifetime Estimation is based on Load Cycle Counting during the Operation of the Wind Turbine used for predictive Maintenance.

Structural Monitoring

The Occurrence of Cracks and Defects can be detected at an early Stage to prevent catastrophic Failures and lengthy Downtimes. Data can be also used for Ice Load Monitoring.

Active Control

Real time Loads act as in Input for Individual Blade Pitch Control especially for large Wind Turbines where the Wind is very turbulent over the Rotor spam.

Integration of FIBRADAPT

FIBRADAPT™ System Additional Applications

• Integration into the SCADA System• Standard Application for Design Verifications• Development of a Wind Park Management System

based on Load Data• Black Box Functionality

Test Installation – Application of FIBRADAPT

Sensor Layout in Test

Blade 1

Installation of FIBRADAPT during the Production of the Blade

Bending Moment flapwise

50 100 150 200 250 300 350 400 450 500 550 600Time [s]

4E+05

6E+05

8E+05

1E+06

1.2E+06

1.4E+06

Bendin

g M

om

ent [k

Nm

]

Mbf_1_fosCopyright©2005 WindForce GmbH

0 2 4 6 8 10 12 14 16 18 20Time [s]

4E+05

6E+05

8E+05

1E+06

1.2E+06

1.4E+06

Bendin

g M

om

ent [k

Nm

]

Flap- and edgewise Loads during Operation

450

500

550

600

650

343 345 347 349 351 Time [s]

stra

in(1

6) [

mik

rost

rain

]

-600

-400

-200

0

200strain (12) [m

ikrostrain]

Sensor16 Sensor12

Frequency Analysis (Turbine Operation)

0 0.2 0.4 0.6 0.8 1 1.2Frequenz [Hz]

3

4

FF

T-M

bf

FFT_Mbf_1

FFT_Mbf_1_fos

Copyright©2005 WindForce GmbH 2004-08-12 18-40-00_fft

Project planning - Outlook

• Integration of FIBRADAPT into a Serie• Development and testing of active Control Algorithms for

FIBRADAPT• Development of Methods for controlling and operating,

based on Variables• Development of Methods for assuring the Application

Process in Serial Production in Offshore Installations• Development of Software for Load Monitoring and

Residual Lifetime Estimation

www.wind-force.comsabrina.kuhnt@wind-force.com

Die Entwicklung wird teilweise finanziert durch Mittel aus dem PFAU Programm der BIS BremerhavenWindForce GmbH wird unterstützt durch Mittel des GRW Programms des Landes Bremen

Thank you for your attention!