1 permanent performance Design of the Z72 wind turbine with direct drive PM generator Introduction The turbine design The conversion system Testing

1permanent performance

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


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


Zephyros in value chain

1. Wind turbine design (>100 years of experience)

2. Certification (Germanische Lloyd / Det Norske Veritas)

3. Wind turbine sales (direct + franchise)

4. Manufacturing components (suppliers)

5. Wind turbine assembly (in own assembly hall)

6. After sales / service

7. Electricity production

8. Electricity sales

2 3 4 5 6 7 8 1



Introduction

The turbine design




Does it sell ?

How to improve


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


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




Installation hoist



Introduction

The turbine design




Does it sell ?

How to improve


Single line diagram



Use of voltage source converter Universal 50 - 60 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


The structural design


The voltage level

86

88

90

92

94

96

98

100

[%]

5 7 10Windspeed

Influence of generator type and voltage level on performance

PMHV

PMLV

WRHV

WRLV


The stator winding

Preformed wire

Advantage : Slot fill factor of 0.7

: High quality insulation

Disadvantage : More connections

: Magnetic slot wedges

Vacuum impregnated stator


permanent performance 17



Generator specifications

Rated shaft power 1670 kW Temperature rise class F Rated electrical power 1562 kW Insulation class F (H) Rated air gap torque 862 kNm Standards IEC34 Rated voltage 3000 V Protection by enclosure IP54 Rated current 327 A Cooling type IC40 Power factor 0.92 Rotor inertia 35000 kgm2

Frequency 3 - 9.25 Hz (rated) Total weight 47200 kg Rotational speed 9 - 18.5 rpm (rated) Stator weight 25000 kg Pole number 60 Rotor weight 12500 kg Pole angle 33.5 deg. Bearing support cone 5000 kg Torque harmonics 100% fundamental (862 kNm) Bearing weight 4000 kg < 1% 6th harmonic (55.5 Hz) PT 100 stator 6 < 1% 12th harmonic (111 Hz) PT 100 generator air 2 < 1% 24th harmonic (222 Hz) PT 100 bearing 2 Short circuit current 569 A (sustained) Airgap distance sensors 4 Ambient temperature 40 °C Bearing greasing unit 1 Radial pull 98 kN/mm between stator and

rotor due to excentricity Maximum magnetic force

45 kN magnetic pulling force of one pole.

permanent performance 20



Introduction

The turbine design




Does it sell?

How to improve


Full scale B2B test

1. Light load test 5 Endurance test

2. Overspeed 6 Optimisation grounding concept

3. Short circuit test 7 Optimisation closed loop control

4. Firing through


Full scale B2B test


Results

Results: Good dynamic response Controllable generator

current

Limitations: Poor dynamic test

conditions Poor cooling conditions


Performance

Track record (dec 2002 – feb 2004)

Capacity factor 28%

4500 MWh produced

Overall availability 2003: 84%

0

200

400

600

800

1000

1200

1400

1600

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Wind speed [m/s]

Pow

er [k

W]

Calculated

Measured


Heat run

Maximum Tstator 86 °C, Tbearing 75 °C and Tambient 17 °C

Heat run at full load during 24 hours

-10

0

10

20

30

40

50

60

70

80

90

1 25 49 73 97 121 145 169 193 217 241 265 289 313 337 361 385 409 433 457 481 505 529 553 577 601 625 649 673 697 721 745 769 793

Tstat-2

Tstat-3

Tstat-4

Tstat-5

Tstat-6

Tambient


Improvements

Prototype 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

Modifications ventilation system



Introduction

The turbine design




Does it sell?

How to improve


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) € 2,5001 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


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



Introduction

The turbine design




Does it sell?

How to improve


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


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!



Introduction

The turbine design




Does it sells ?

How to improve


Cost distribution

distribution of costing

29%

10%

1%3%

0%3%12%

25%

15%

2%0%

rotor :

drivetrain:

hydraulic:

nacelle:

cover :

yaw mechanism:

tow er:

generator:

E-system/converter:

transformer :

auxiliary equipment:


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

Documents

1 permanent performance Design of the Z72 wind turbine with direct drive PM generator Introduction The turbine design The conversion system Testing