PHM Application for Utility-scale Wind Turbines

Brogan Morton, NRG Systems

Presentation Overview

• Why Health Monitoring for Wind Turbines?• Operational Cost Drivers• CBM/PHM Challenges– System Considerations– Operating Conditions– Diagnosis / Knowledge Creation

Why Health Monitoring?• Not driven by safety or

operational effectiveness• It’s about the bottom line– Cost Avoidance• Maintenance Cost Optimization

– $150k gearbox + $100k crane call – $30k-$50k uptower replacement

• Prevent failures by finding failure drivers– misalignment, imbalance, etc.

Why Prognostics?

Operational Cost Drivers

35% to 45% of OPEX

Maintenance Drivers

Drivetrain causes 50% of downtime

Typical Drivetrain Layout

Hub & Rotor(12-20 RPM)

Doubly-Fed Induction Generator

(900-1600 RPM)3 Stage Gearbox -1 planetary / 2 helical

(80:1 - 100:1 ratio)

Main Shaft

MainBearing

3-stage Gearbox

Generator

• 17 Bearings• 9 Gears• 8 Shaft

Low Speed Shaft

Int. Speed Shaft

High Speed Shaft

Car

rier

Pla

te

Typical Drivetrain Layout

Systems Considerations• Distributed power source– Goshen North ~ 124.5MW using 83 1.5MW turbines– 11,000 acres, 28 miles of access roads

Systems Considerations• Turbines are difficult to access– Climb an 80m (262 ft) tower then hoist tools– Hand-held CMS incurs a large labor cost

System Considerations

• IT Infrastructure– Down-tower connection– Local network infrastructure– NERC Critical Infrastructure Protection (CIP)– Operation network security (AIC vs CIA)

Operating Conditions

• Large variations in speed– DFIG– Tower Shadow– Wind Shear Profile

• Large variations in torque/power– 10% - 105% of rated

Main Rotor Speed

Knowledge Creation

Manually translating data into a diagnosis for every turbine has a large cost!

Which is most useful to an operator?• 01000011 01101000 01100001 01101110 01100111

01100101 00100000 01101101 01100001 01101001 01101110 00100000 01100010 01100101 01100001 01110010 01101001 01101110 01100111

• 43 68 61 6e 67 65 20 6d 61 69 6e 20 62 65 61 72 69 6e 67 0d 0a

• Change main bearing