How has reliability of technology developed through time

1
How has reliability of technology developed
through time?
Erika Echavarria, TU Delft - DUWIND,
Netherlands Berthold Hahn, ISET, Germany
2
Content

• Objectives
• WMEP
• Results
• Conclusion
• Future work

3
Objectives

• Component reliability through time with respect
  to the technology,
• using the WMEP database.

• Specific Objectives
• Failure rates of wind turbines through
  operational years
• Rate of exchange of main components
• Failure rates of components through 2 study cases

4
250 MW Wind Programme database

• Cause of malfunction
• Effect of malfunction
• Removal of malfunction
• Replaced main component

• Reason for repair
• Downtime
• Costs stated on bill
• Comments

5
Failure Rates per component
6
General development of reliability
Failure rates of wind turbines
81
15
3
Distribution of the 1500 wind turbines per
category
7
General development of reliability
Annual exchange rate of main components
1500 wind turbines
8
Stall versus pitch
Annual Fault Frequency of all Components
58
42
Distribution of the 1500 wind turbines per
category
9
Induction versus synchronous generator
Annual Fault Frequency of the Generator
83
27
Distribution of the 1500 wind turbines per
category
10
Conclusions (1/2)

• Reliability through time
• For wind turbines it increases
• For newly introduced models it is very low
• It escalates inversely with wind turbine size
• Blades, generators, and gearboxes have the
  highest rate of exchange.
• Offshore versus onshore availability differently
  affected by component reliability

11
Conclusions (2/2)

• Reliability of components through time
• Highly influenced by wind turbine type and size
• Wind turbines with pitch or stall system have
  equivalent reliability
• Synchronous generators are less reliable than
  induction generators
• There is no general behaviour through time

12
Future Work

• Maintenance records The wind community should
  work together gathering data on new turbines.
• Design approach to target faults and to remove
  potential failures at the design stage in order
  to increase reliability and availability of wind
  farms.
• Maintenance (i.e. RAMS/LCC methods) has to be
  improved to keep up with new challenges,
  technologies, and escalation.

13
Thank you for your attention
14
Stall versus pitch
Annual Fault Frequency of Mechanical Brakes
15
Stall versus pitch
Annual Fault Frequency of Hydraulic System
16
Stall versus pitch
Annual Fault Frequency of the Rotor
17
Induction versus synchronous generator
Annual Fault Frequency of Power Electronics