Technological Advances in Hydraulic Drivetrains for Wind Turbines

CTO Knud Erik Thomsen

EWEA 2012 Annual Event, Copenhagen

Conference session: Technology for drivetrains

Track: Hardware technology

Tuesday, 17 April 2012, 16:00 - 17:30

Contents

2

Company introduction

Technology trends as basis for developing hydraulic transmission

ChapDrive compact and integrated variable hydraulic drivetrain

How can ChapDrive avoid using frequency converters?

Concept and functionality

Measurements and model verification

Technical benefits impact financial performance

Question and answer

ChapDrive AS - proprietary

20 employees in Norway, Denmark, UK and China supported by the investors:

- NorthZone Ventures, Statoil Venture, Hafslund Venture, Viking Venture and Investinor

Company introduction

3ChapDrive AS - proprietary

3+ MW integrated drive train

5+ MW conceptual design

225 kW test turbine

50 kW test bench

900 kW test turbine

300 kW test bench

2005 2007 2009 2011 – 2013

From left: Headquarter in Trondheim, subsiduary in Denmark, workshop and test site in Trondheim

Jens Anders Jensen CEO

Background CSO in Vestas Chairman of the Danish Wind Industry 10 years experience in the wind industry

Knud Erik ThomsenCTO

Background15 years in R&Dat Vestas Head of mechanicaland electricalengineering

Åsmund FurusethVP & Co-founder

BackgroundFormer CEOProject managerTechnologyTransfer Office NTNU

Peter ChappleSenior Scientist &Co-founder

BackgroundProfessor in hydraulics, Technical director Staffa Products, Industry consultant

Thor SchjetneProject Director

BackgroundOffshore Oil and gas engineering atReinertsen

Paul ChangMarketing Director

BackgroundMD in Hägglunds Drives China and R&D Asia Pacific Center. 25 years experience in the hydraulic industry

Pål Engebretsen – Chairman(Former CEO Bergen Group and Chairman of Scanwind)

Board of directors with industrial and business development expertise

Torben Bjerre Madsen (Former deputy-CEO in Vestas)

Tellef Thorleifsson(NorthZone Ventures)

Ståle Myhre(Statoil Venture)

Joachim Cock(Hafslund Venture)

Jostein Vik(Viking Venture)

Steinar Fossen (Investinor)

Management with broad experience within hydraulics and wind power

ChapDrive AS - proprietary4

Technology trends as basis for developing hydraulic transmission

Market trends: Turbine sizes are increasing Reliability must be improved Cost of energy must come down

Challenges facing the wind industry: Top weight reduction is increasingly critical Mechanical gearbox and frequency

converter are statistically unreliable Sourcing and cost of permanent magnets

Hydraulic transmissions are generally robust and will reduce top weight for wind turbines

High efficiency hydraulic technology enables competitive efficiency

New technology is driven by the industry for mobile hydraulic systems

TWh annual wind power production

40

500

1000

1500

2000

2500

3000

1990 2008 2015 2025 2035

‘85

Rot

or d

iam

eter

(m

)

‘89 ‘93 ‘97 ‘01 ‘05 ?

0.05

YearMW 0.3 0.5 1.6 4.5 8/10

15

160

112

Turbine size development

Market development for wind power

5ChapDrive AS - proprietary

ChapDrive compact and integrated variable hydraulic drivetrain

6

Pump

Motor

Electrically Excited Synchronous Generator, EESG

Control System

Perfectionvia

Simplicity

ChapDrive AS - proprietary

ChapDrive compact and integrated variable hydraulic drivetrain

7

Fewer critical components:

No mechanical gearbox

- causing high maintenance costs on today’s wind turbines

No need for permanent magnets (PM)

- high cost rare earth materials

No frequency converter

- causing the highest failure rates and most down time on today’s wind turbines

No transformer

ChapDrive AS - proprietary

GearboxDouble fed

induction generator Frequency converter Transformer

Grid

10 kV

Grid

10 kV

Hydraulic transmission

EE synchronous generator

How can ChapDrive avoid using frequency converters?

8ChapDrive AS - proprietary

GearboxDouble fed

induction generator Frequency converter Transformer

Grid

10 kV

Grid

10 kV

EE synchronous generator

Speed control

Speed control

Hydraulic transmission

How can ChapDrive avoid using frequency converters?

9ChapDrive AS - proprietary

Grid

10 kV

Gearbox(Fixed, e.g. 1 : 100 @ 3 MW)

Double fed induction generator Frequency converter Transformer

Grid

10 kV

Frequency converter Transformer

Grid

10 kV

Direct drive PM generator(Fixed 1 : 1)

Gearbox

Direct drive

ChapDrive

Hydraulic transmission(1 : variable)

Speed control

Speed control

How can ChapDrive avoid using frequency converters?

ChapDrive AS - proprietary10

EE synchronous generator

Concept and functionality

Transmission ratio: Variable 1:100 – 1:300for a 3 MW wind turbine

Result: High energy yield from the wind Low loads on the turbine structure and the

turbine components

ChapDrive AS - proprietary11

Concept and functionality

Component At rated power

Pump 96%

Hydraulic motor with digital valves

95-96%

EE Generator 98%

Summary 89-90%

Component At rated power

PM Generator 94-95%

Power electronics + Transformer

97%

Summary 91 – 92%

Component At rated power

Gearbox 96-97%

Generator 98%

Power electronics + Transformer

97%

Summary 91-92%

Gearbox Direct Drive ChapDrive

ChapDrive AS - proprietary12

ChapDrive control system

Pitch control (blades)

Excitation control (generator)

Displacement control (hydraulic motor with digital valves)

ChapDrive core technology

Control system for hydraulic motor, pitch system and generator (patents grated)

Hydraulic transmission for wind turbines (patents granted)

Design and integration of hydraulic drive train solutions in wind turbines(patent pending)

Products

The ChapDrive control system is essential for control of the vital features of a wind turbine with a hydraulic drive train solution (patents granted)

Prototype has been verified in the ChapDrive wind turbines

The ChapDrive Integrated Hydraulic Transmission is essential for low top weight and robustness (patent pending)

Design under development

ChapDrive integrated hydraulic transmission

Concept and functionality

13ChapDrive AS - proprietary

Model verification

Dynamic models

ChapDrive Control

Software

Wind turbine

ChapDrive Control System

1

2

3

4x 10

4

T p [

Nm

]

System inputs

4

4.5

5

5.5

6x 10

-5

Dm

[m

3/r

ad]

30

35

40

45

50

p [

rpm

]

System outputs

50

100

150

200

p m,in

[ba

r]

0 100 200 300 400 500 600 700 800 9000

50

100

150

Pg [

kW]

(Measurement start time: 2011-12-07 11:24:00) t [s]

20

40

60

80

p [

rpm

]

System outputs

50

100

150

200

p m,in

[ba

r]

0 100 200 300 400 500 600 700 800 9000

50

100

150

Pg [

kW]

(Measurement start time: 2011-12-07 11:24:00) t [s]

Comparison

Model tuning

Simulation results

Measurements

Measurements and model verification

ChapDrive AS - proprietary14

10 minutes mean values are shown from the test wind turbine (ChapDrive 1 - 225 kW) for a period of 5 month

Optimal rotor speed at all time ensuring maximum energy yield from the wind

Generator speed is always constant

Measurements and model verification

ChapDrive AS - proprietary15

Method Combined and optimised control of:

• Pitch• Displacement

(transmission ratio)• Excitation

Results Constant power above rated wind

speed Power and torque fluctuations

eliminated due to fast displacement control

Full control over reactive power

Measurements and model verification

ChapDrive AS - proprietary16

Technical benefits impact financial performance

Robust light-weight variable hydraulic drivetrain with an electrically excited synchronous generator directly connected to the grid

This means: No mechanical gearbox No need for permanent magnets No frequency converter No transformer

CAPEX reduced with up to 20%

OPEX reduced with up to 15%

Cost of Energy reduced with up to 20%

AEP is up to 2% lower than other technologies

0

200

400

600

800

1000

1200

1400

0 2 4 6 8 10 12

Siemens 6 MW

Enercon 4.5 MW

Enercon 6 MW

Enercon 2 MW

Vestas3 MW

Siemens 3 MWSiemens 2.3 MW

Vestas7 MW

RePower 5 MW

Siemens 3.6 MW

Top weight scaling with different drive trains

Top

head

mas

s (t

on)

Nominal power (MW)

Trad

itiona

l gea

rbox

Permanent m

agnet DD

ChapDrive hydraulic Drive

Elect

rom

agne

tic D

D

ChapDrive AS - proprietary17

Q&A

Thank you for your attention!

Professor Brochs gt 2Trondheim7030 Norway

www.chapdrive.com