1. Design of the Z72 wind turbine with direct drive PM generator
Introduction
The turbine design
The conversion system
Testing and operational experience
Commercial advantage of the Z72
Does it sell
How to improve
C.J.A. Versteegh (R & D manager) Trondheim, June 15, 2004
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2. Introduction
In 2000 a consortium has been established to upscale the Lagerwey DD turbine. Participation of ABB in generator and converter design
In April 2003 Zephyros has become an independent wind turbine manufacturers with Triodosbank and Renerco as shareholders.
Presently: - prototype track record 1.5 year
- multi discipline small organisation
- franchise business model
- 30 turbines in the order book
The LW 750kW
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3. Zephyros in value chain1 2 3 4 5 6 7 8
Wind turbine design (>100 years of experience)
Certification (Germanische Lloyd / Det Norske Veritas)
Wind turbine sales (direct + franchise)
Manufacturing components (suppliers)
Wind turbine assembly (in own assembly hall)
After sales / service
Electricity production
Electricity sales
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4. Design of the Z72 wind turbine with direct drive PM generator
Introduction
The turbine design
The conversion system
Testing and operational experience
Commercial advantage of the Z72
Does it sell ?
How to improve
permanent performance

5. Design requirements Top of range design (1999) Integrated design
Single bearing concept
Minimum number of components
Full size 4-q converter
No transport restrictions; minimum hoisting capacity
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6. Base design parameters
Rotor diameter 70 m
Nominal rotational speed 18 (<100 dB(A))
Nominal power 1500 kW
Protection IP 54
Maximum transport size 4 m
Maximum transport weight 50 tonnes
Offshore application; no noise restriction
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9. Installation hoist
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10. Design of the Z72 wind turbine with direct drive PM generator
Introduction
The turbine design
The conversion system
Testing and operational experience
Commercial advantage of the Z72
Does it sell ?
How to improve
permanent performance

11. Single line diagram
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12. The conversion system Use of voltage source converter
Universal Hz design
Good connectivity to grid
Electric braking and positioning of rotor
Generator loaded with minimum AC current
Capable to operate under line dips
Sensor less drive
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13. The structural design
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14. The voltage level
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15. The stator winding Preformed wire Advantage : Slot fill factor of 0.7
: High quality insulation
Disadvantage : More connections
: Magnetic slot wedges
Vacuum impregnated stator
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19. Generator specifications
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21. Design of the Z72 wind turbine with direct drive PM generator
Introduction
The turbine design
The conversion system
Testing and operational experience
Commercial advantage of the Z72
Does it sell?
How to improve
permanent performance

22. Full scale B2B test Light load test 5 Endurance test
Overspeed 6 Optimisation grounding concept
Short circuit test 7 Optimisation closed loop control
Firing through
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23. Full scale B2B test
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24. Results Results: Good dynamic response Controllable generator current
Limitations:
Poor dynamic test
conditions
Poor cooling conditions
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25. Performance Track record (dec 2002 – feb 2004) Capacity factor 28%
4500 MWh produced
Overall availability 2003: 84%
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26. Heat run Maximum Tstator 86 °C, Tbearing 75 °C and Tambient 17 °C
Heat run at full load during 24 hours
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27. Improvements Prototype modifications Design modifications
Improvement of noise level
Improvement of control algorithm
Safety and control software fine tuning
Modifications ventilation system
Design modifications
Double row TRB (option)
State of art PLC and SCADA
Nacelle casted and not welded
Hydraulic yaw brakes
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28. Design of the Z72 wind turbine with direct drive PM generator
Introduction
The turbine design
The conversion system
Testing and operational experience
Commercial advantage of the Z72
Does it sell?
How to improve
permanent performance

29. Benefits Competitive with catalogue price of 1500 k€
Costs of operation during life-time
maintenance costs (-30%) € 3,000
availability (+1% point) € 3,000
insurance fee (-25%) € 2,500
higher electricity yield (+2%) € 6,000
compared to identical machine but with conventional generator
reservation for repairs (-2,500) € 2,500
1 in 5 turbines need to replace gearbox after warranty. Cost of new gearbox + lost production: € 250,000 €17,000 per year
Capital costs
lighter crane needed (- € 25,000 to – € 50,000)
Installation on 600kW locations
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30. 1.5 – 2.0 MW Upgrade to 2 MW Conversion system designed for 2 MW
Make use of 7 kV insulation system
Optimum use of variable speed behaviour
Noise level increase 3 dB(A)
PPV improvement of 8 % (for class 3 wind climate)
Minor extra investment cost
DNV prototype certificate for both obtained
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31. Design of the Z72 wind turbine with direct drive PM generator
Introduction
The turbine design
The conversion system
Testing and operational experience
Commercial advantage of the Z72
Does it sell?
How to improve
permanent performance

32. The market Wind market 2002: $7bn Past 5 years : CAGR >30%
Till 2012: CAGR 10-20%
Trends:
- offshore development
- large scale wind farms
- big multi MW turbines
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33. Zephyros SWOT analysis
Strengths
The design; ±2 years ahead of market with 2MW PMDD design
Partners involved, esp. ABB
Flexibility, independence
Opportunities
Market moving towards DD
Offshore gaining importance
Worldwide network can be rolled out very quickly
Weaknesses
Track record
Financial power
Control over manufacturing
Threats
Other players developing DD
Enercon (price reductions)
GE patent (in US only)
patent issue in Europe is solved!
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34. Design of the Z72 wind turbine with direct drive PM generator
Introduction
The turbine design
The conversion system
Testing and operational experience
Commercial advantage of the Z72
Does it sells ?
How to improve
permanent performance

35. Cost distribution
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36. Future developments Short term development
Improvement of PPR with 10 % by:
Make use of existing structural design
Increase of rotor diameter to 78 m
Development areas:
Independent blade pitching (to reduce fatigue loads)
Low solidity blade design (to reduce extreme loads)
Integrated blade pitch and converter control
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