Wind Power - A Technology enabled by power electronicsmsgmedia/PCC/PCIM_Asia_2013-Presentatio… · A Technology enabled by power electronics ... AC DC DC AC AC DC DC AC..... Transformer

Wind Power - A Technology enabled by power electronics

Center of Reliable Power Electronics


Prof. Frede Blaabjerg

Professor, IEEE Fellow

[email protected]

Aalborg University Department of Energy Technology

Aalborg, Denmark

CORPE

www.corpe.et.aau.dk

http://www.corpe.et.aau.dk/

mailto:[email protected]

Outline

2 Center of Reliable Power Electronics

► Aalborg University and Department of Energy Technology

► Power Electronics for Wind Turbines

► Reliability Challenge of Power Electronics

► Power Converter Operation in Wind Turbines

► Conclusions

Wind Power -

A Technology enabled by power electronics


Aalborg University and

Department of Energy Technology,

Denmark

Aalborg University - Denmark


PBL-Aalborg Model (Project-organised and problem-

based)

Inaugurated in 1974

19,000 students

2,500 faculty

Aalborg University - Campus


Department of Energy Technology


Energy production - distribution - consumption - control

HEAT

LOADS POWER STATION

SOLAR CELLS

WIND TURBINE

MOTOR

PUMP

ROBOTICS

REFRIGERATOR

TELEVISION

LIGHT

TRANSFORMER

INDUSTRY

=

POWER SUPPLY

ac dc

TRANSFORMER

COMPEN - SATOR

FUEL CELLS

FUEL [

COMMUNICATION

COMBUSTION ENGINE

SOLAR ENERGY

TRANSPORT

3 3 3 1 - 3

3

DC

AC

~

POWER STATION

SOLAR CELLS

WIND TURBINE

MOTOR

PUMP

ROBOTICS

REFRIGERATOR

TELEVISION

LIGHT

TRANSFORMER

INDUSTRY

=

POWER SUPPLY

ac dc

TRANSFORMER

COMPEN - SATOR

FUEL CELLS

FUEL [

COMMUNICATION

COMBUSTION ENGINE

SOLAR ENERGY

TRANSPORT

3 3 3 1 - 3

3

DC

AC

~

DC

AC

DC

AC

PRIMARY

FUEL

CHP

Energy

Storages

Energy

Storages

FACTS/CUPS



Strategic Networks

• EMSD

• CEES

• ECPE

• VE-NET

• DUWET

• WEST

• VPP

• REN-DK

• HUB NORTH

• Energy Sponsor

Programme

Fluid Power and

Mechatronic

Systems

Fluid Mechanics

and Combustion

Electric Power

Systems

Power Electronic

Systems

Electrical

Machines

• 50+ VIP

• 70+ PhD

• 10+ Guest Researchers

• 10+ Research Assistants

• 22 TAP

Smart Grids and Active Networks

Wind Turbine Systems

Fluid Power in Wind and Wave Energy

Biomass

Photovoltaic Systems and Microgrids

Modern Power Transmission Systems

Fuel Cell and Battery Systems

Automotive and Industrial Drives

Efficient and Reliable Power Electronics

Thermoelectrics

Green Buildings

Multi-disciplinary Research Programmes Lab. Facilities

• Power Electronics

Systems

• Drive Systems Tests

• Fluid Power

• Power Systems & RTDS

• Micro Grid

• High Voltage

• DSpace

• PV Converter &

Systems

• Laser Systems

• Fuel Cell Systems

• Battery Test

• EMC

• Vehicles Test Lab

• Biomass Conversion

Facilities

• Proto Type Facilities

Thermal Energy

Systems



Power Electronics for Wind Turbines

Energy and Power Challenge


Four main challenges in energy

Sustainable energy production (backbone, weather based, storage)

Energy efficiency

Mobility

Infrastructure

EU Set-plan (20-20-20) and beyond

Danish Climate Commision – Independent in 2050 of fossil fuel

Germany – no nuclear in the future

Globally large activity

Different initiatives

Renewable Electricity in Denmark


Key figures for proportion of renewable electricity

Key figures 2010 2011 2020 2035

Wind share of net generation in year 21.3% 29.4% 50%*

Wind share of consumption in year 22.0% 28.3%

RE share of net generation in year 32.8% 41.1% 100%*

RE share of net consumption in year 33.8% 39.0%

(Data source: Energinet.dk)

(Data source: Energinet.dk) (*target value)

2011 Renewable Electricity Generation

in Denmark

11

Energy and Power Challenge in DK

Very high coverage of distributed generation.

Bri

ef

Tech

no

logy

De

velo

pm

en

t


Development of Electric Power System in Denmark


From Central to De-central Power Generation

(Picture Source: Danish Energy Agency) (Picture Source: Danish Energy Agency)

Renewable Energy System


Important issues for power converters Reliability/security of supply

Efficiency, cost, volume, protection

Control active and reactive power

Ride-through operation and monitoring

Power electronics enabling technology

Global Wind Turbine Capacity


Large investment a critical factor

New wind turbines development cost is expensive

Globally it changes from country to country annually

Worldwide wind power capacity

(Giga Watts)

…

…

Wind Turbine Development


Bigger, cheaper and more efficient

3.6-7 MW prototypes running (Vestas, GE, Siemens Wind, Enercon)

2-3 MW WT are still the “best seller” on the market

Global installed wind capacity (up to 2012): 282 GW, 2012: 44 GW

1980 1985 1990 1995 2000 2005 2011

50 kW

D 15 m

100 kW

D 20 m

500 kW

D 40 m

600 kW

D 50 m

2 MW

D 80 m

5 MW

D 124 m

7~8 MW

D 164 m

Soft starterRotor

resistanceRotor

power

Full generator

power

≈ 0% 10% 30% 100%

Role:

Rating:Power

Electronics

2018 (E)

10 MW

D 190 m

Grid Codes for Wind Turbines


Conventional power plants provide active and reactive power, inertia

response, synchronizing power, oscillation damping, short-circuit

capability and voltage backup during faults.

Wind turbine technology differs from conventional power plants

regarding the converter-based grid interface and asynchronous

operation

Grid code requirements today

► Active power control

► Reactive power control

► Frequency control

► Steady-state operating range

► Fault ride-through capability

Wind turbines are active power plants

Power Grid Standards – Normal Operation

17

Part of frequency control Reactive power capability

Designed for all ratings

Set-point may be given by power system operator

Requirements to be a power station


100%

Available power

fg (Hz)

48 49 5251

51.350.15

75%

50%

25%

50

49.8548.7

With full

production

With reduced

production

P/Prated (p.u.)

Q/Prated (p.u.)

0.2

0.4

0.6

0.8

1.0

0.4OverexcitedUnderexcited-0.3

Underexcited

Boundary

Overexcited

Boundary

Power Grid Standards – Ride-Through Operation

18

0

25

75

90

100

150 500 750 1000 1500

Voltage(%)

Time (ms)

DenmarkSpain

Germany

US

Keep connected

above the curves

Grid voltage dips vs. withstand time

100%

Iq /Irated

Vg (p.u.)

0.5

0

Dead band

0.9 1.0

20%

Reactive current vs. Grid voltage dips

Withstand extreme grid voltage dips.

Contribute to grid recovery by injecting Iq.

Higher power controllability of converter.

Requirements during grid faults


Wind Turbine Concepts


► Wound-rotor induction generator

► Variable pitch – variable speed

► ±30% slip variation around

synchronous speed

► Power converter (back to back/

direct AC/AC) in rotor circuit

► Variable pitch – variable speed

► With/without gearbox

► Generator

Synchronous generator

Permanent magnet generator

Squirrel-cage induction generator

► Power converter

Diode rectifier+boost DC/DC+inverter

Back-to-back converter

Direct AC/AC (e.g. matrix,

cycloconverters)

20

Back-to-back two-level voltage source converter

Proven technology

Standard power devices (integrated)

Decoupling between grid and generator (compensation for

non-symmetry and other power quality issues)

Need for major energy-storage in DC-link (reduced life-time and

increased expenses)

Power losses (switching and conduction losses)

Back-to-back VSC

Power Electronic Converters

Transformer

2L-VSC

Filter Filter

2L-VSC


21

Power converters

Proven technologies today

Boost and Voltage Source Converter to grid


Transformer

Filter Filter

Transformer

Filter Filter

Current Source Inverter to grid


22

Parallel of low voltage power converters


Multi-winding low voltage


...

Multi winding

generator

AC

DC

DC

AC

AC

DC

DC

AC

...

...Transformer

2L-BTB

2L-BTB

Grid

...

...

Transformer

AC

DC

DC

AC

AC

DC

DC

AC

...

Generator

2L-BTB

2L-BTB

Grid

Also proven technologies today

23

Multi-level topologies +6 MW

Transformer

3L-NPC

Filter Filter

3L-NPC

Transformer

open windings

Filter Filter

3L-HB 3L-HB

Three-level NPC

Half-bridge and open-winded transformer


24

5L-HB

Transformer

(open windings)

5L-HB

Filter Filter

3L-NPC

Transformer

(open windings)

5L-HB

Filter

Filter

Half-bridge, five-level

Three-level and five-level



25

...

Cell 1

Cell N

...

AC

DC

DC

AC

AC

DC

DC

AC

...

AC

DC

DC

AC

AC

DC

DC

AC

MFT

MFT

...

...

To grid

DC

DC

DC

AC

DC

DC

DC

AC

Rectifier

MVDC

To generator

Medium frequency transformer

Stacked output converter



Control Structure for a Wind Turbine System


Gear-box

LCLLow pass

filter

Vgenerator

Igenerator

Grid fault ride through

and grid support

Igrid

Vgrid

Vdc

Power Maximization

and Limitation

Inertia

Emulation

Power

Quality

Extra functions

WT specific functions

Basic functions (grid conencted converter)

Current/Voltage

Control

Vdc

Control

Energy

Storage

Grid

Synchronization

AC

DC

DC

AC

Xfilter

Pitch actuator

Wind speed

Superviosry commmand from TSO

wgenerator

SG

IG

DFIGlocal

load

utility

micro-

grid

Braking

Chopper

Pulse Width Modulation

Power has to be controlled by means of the aerodynamic system and has to

react based on a set-point given by a dispatched center or locally with the goal to

maximize the power production based on the available wind power.

Current Development Example


Vestas V164 offshore turbine

Rated power: 8,000 kW

Rotor diameter: 164 m

Hub height: min. 105 m

Turbine concept: medium-speed gearbox,

variable speed, variable pitch, full-scale

power converter

Generator: permanent magnet

Vestas Wind Systems A/S Denmark

Target market: Big offshore farms

28

Vestas V80–2.0 MW

Horns Reef I 160 MW, Horns Reef II 209.3 MW • 80 x 2MW (Vestas V80, in

operation Dec 11, 2002)

• 91 x 2.3MW (Siemens SWT-2.3-93, in operation Sep 17, 2009)

Rotor Diameter 80 m Hub Height 60-100 m Weight 227-303 tons Min/Max rotation speed 9/19 rounds/minute Min/Nom/Max Wind 4/16/25 m/s Gear box Yes (1:100.5) Generator DFIG (4 pole – slip rings)

Current Development Example – Wind Farm


Improved performance of Wind Turbines

Integration with a battery storage system

Take part in primary and secondary control


WBG devices

30

Wide-Band-Gap Devices: Ways to Higher Power Density

January 27, 2012 DB-4

WBG

devices

≤ 200 400 ~ 600 ≥ 1200 Voltage (V)

Power (W)

10

100

1k

10k

GaN HEMTs MHz switching

Low conduction loss

Conduction

loss

Switching

loss

High-temp.

operation

Smaller cooling

system size

High-freq. passive

components

Smaller

passives sizes Improved

power

density

GaN diodes & transistors

SiC Schottky diodes

Better FOM, Competitive cost

No reverse recovery

SiC BJTs / IGBTs

MOSFETs / JFETs

Schottky / PiN diodes

High voltage

High temperature

Source D, Boroyevich - CPES


SiC Devices

31 June 18, 2013

Source D, Boroyevich - CPES

Major SiC Device Developers

January 27, 2012 DB-23

600 V 1200 V 1700 V 3-7 kV 10 kV

Schottky

Blocking

Voltage

JFET Normally-on/-off

JFET Normally-off

Schottky diode

Schottky diode JFET

Normally-on

Schottky diode Super-junction

BJT

Thyristor 6.5 kV

BJT

MOSFET

Schottky diode

Schottky MOSFET MOS

MOSFET

Mainstream: 1.2 kV switches

A lot of research

going on for high-

voltage SiC devices

MAINSTREAM



Wind Turbine – power electronic components

Emerging devices soon ready for wind power processing

IGBT module IGBT Press-pack IGCT Press-pack SiC MOSFET module

Power Density Low High High Low

Reliability Moderate High High Unknown

Cost

High High High

Failure mode Open circuit Short circuit Short circuit Open circuit

Easy maintenance + - - +

Insulation of heat sink + - - +

Snubber requirement - - + -

Thermal resistance Large Small Small Moderate

Switching loss Low Moderate Moderate Low

Conduction loss Moderate Moderate Moderate Large

Gate driver Moderate Moderate Large Small

Major manufacturers Infineon, Semikron, Mitsubishi,

ABB, Fuji Westcode, ABB ABB Cree, Rohm, Mitsubishi

Medium voltage ratings 3.3 kV / 4.5 kV /6.5 kV 2.5 kV / 4.5 kV 4.5 kV / 6.5 kV 1.2 kV

Max. current ratings 1.5 kV / 1.2 kA / 750 A 2.3 kA / 2.4 kA 3.6 kA / 3.8 kA 100 A-180 A


Wind Turbine system cost – Off-shore

Not only Wind turbine cost


Wind Turbine system cost – before and future

Different trends

But the Cost of Energy will be reduced


Reliability Challenge of Power Electronics in

Renewable Energy Systems

Failures of Power Electronic Systems


Power module

Rotor

module

Control

& Commons

NacelleDrive

trainAuxiliary system Structure

Power

converter

13%Pitch

system

21.3%

Yaw system

11.3%Gearbox

5.1%

Field Experience of Wind Turbines – Normalized Failure Rate

(Source: Reliawind, Report on Wind Turbine Reliability Profiles – Field Data Reliability Analysis, 2011.)


Semiconductor 21%

Capacitor30%

PCB26%

*Data sources: Wolfgang E., “Examples for Failures in Power Electronics Systems,” in EPE Tutorial ‘Reliability of Power Electronic Systems’,

April 2007.

Failure root causes distribution for power electronic systems*

(% may vary for different applications and designs)

Critical Components in Power Electronic Systems

(http://www.alibaba.com)

(www.abb.com)

Availability Impact on Cost-of-Energy (COE)


(source: MAKE Consulting A/S)

CAPEX OPECOE

X

AEP

CAPEX – Capital cost

OPEX – Operation and maintenance cost

AEP – Annual energy production

Lower downtime

Lower OPEX and higher AEP

Higher reliability and better maintenance

Lower COE

Reliability basics

39

Life time models for switching devices

(Source: Semikron)

Thermal cycling parameters ΔTj and Tm are important for device life time.


Reliability basics

40

Thermal models for switching devices

IGCT Diode

ZT(j-c) ZD(j-c)

ZT(c-h) ZD(c-h)

TA

TA TA

Switch

Diode

TA

Clamped Diode

ZD(j-c)

ZD(c-h)

Z(h-a)

TA

Z(h-a)

TC

TH

TC TC

TH

Tj Tj Tj

Note:

Tj: junction temperature, TC: case temperature, TH: heat sink temperature, TA: ambient temperature

Z(j-c): thermal impedance from junction to case, Z(c-h): thermal impedance from case to heat sink, Z(h-a): thermal impedance from

heat sink to ambient

ZT/D(j-c)TA TC

Tj

Rth1 Rth2 Rth3 Rth4

τ1 τ2 τ3 τ4

Thermal model of the impedance ZT(j-c) or

ZD(j-c) from junction to case.

Thermal models are important for ΔTj and Tm .

(Source: ABB)


Reliability basics

41

Reliability evaluation tools for converter

Wind Profiles

Turbine-

Generator

Models

Loss ModelLoss Life time

Model

Thermal

Model

thermal impedance

ΔTj

TmMTTF

turbine, drive, generator topologydevice

vw

Wind speed

IG

VG

Mission Profiles

Wind Profiles

Turbine-

Generator

Models

Loss ModelLoss

Life time

Model-1

Thermal

Model-1VG

ΔTj Tm

CthermCost

turbine, drive, generator topology, devices

vw Chip Size

Model

Wind speed

MTTF

RthermIG

Mission Profiles

From mission profiles to Life time

From life time to cost



Power Converter Operation in Wind Turbines


MW Configurations I

Promising LV configurations

DFIG

Rotor-side

Converter

Filter

Transformer

Grid-side

Converter

C

T1 D1

T2 D2

T1 D1

T2 D2

PMSG

Generator-side

Converter

Filter Transformer

C

T1D1

T2D2

T1D1

T2D2

Grid-side

Converter

2L DFIG

2L PMSG


Normal operation

2L DFIG 2L PMSG

Generator-side

Converter

Grid-side

Converter

Power loss profile


Thermal cycling

Normal operation

Generate-side converter Grid-side converter

Grid faults operation

46

0

2

4

6

8

10

12

0 0.2 0.4 0.6 0.8 1

P

Q

Grid Voltage Vg (p.u.)

Active

/ r

ea

ctive

po

we

r (M

W / M

Va

r)

8 m/s

10 m/s

>12 m/s

-100

-80

-60

-40

-20

0

20

40

60

80

100

0

500

1000

1500

2000

2500

3000

0 0.2 0.4 0.6 0.8 1

Grid Voltage Vg (p.u.)

Cu

rre

nt a

mp

litu

de

(A

)

Ph

ase

an

gle

I - Vg (d

eg

ree)

8 m/s

10 m/s

>12 m/s

Current amplitude (3L-HB, 3L-NPC)

Phase angle

P/Q power vs. Grid voltage Current amplitude & position vs. Grid voltage

When Vg<0.5 p.u. is regardless of wind speeds (100% Iq , no Ip).

When Vg>0.5 p.u. is referring to the generated power/wind speeds (some

room for Ip).

Operation status under balanced LVRT


Grid faults operation

47

Voltage

dips

Normal

operationNormal

operation

Tjmax=116℃

Ju

nctio

n te

mp

era

ture

(℃

)

Time (s)

Dnpc

Tout

TinDout

Din

Voltage

dips

Normal

operationNormal

operation

Tjmax=94℃

Ju

nctio

n te

mp

era

ture

(℃

)

Time (s)

Dnpc

Tout

TinDout

Din

With normal modulation With optimized modulation

Thermal optimized modulation under LVRT

(for 3L-NPC grid inverter)

Junction temperature dynamic response

(wind speed 8 m/s, 0.05 p.u. LVRT, dip time 500 ms)


Summary


► A solution for the long term future in society

► Smart grid also pushed by renewable

► Coordinated control of production and consumption – better integration

► Systems should be able to run in on-grid and off-grid modes

► Wind turbines have been the fastest growing but PV will come

► Wind turbine technology – better performance

- Full scale power electronics

- New generator concepts (e.g. PM, gearless)

- Larger size – lower cost per kWh

- Reliability – a key to lower Cost of Energy

Power Electronics for Wind Power


► A solution for the long term future in society

► Smart grid pushed by renewable

► Increased power production close to the consumption place

► Coordinated control of production and consumption

► Future grid configurations may be different – but intelligent

► Systems should be able to run in on-grid and off-grid modes

► PV-plants will get same specifications as wind turbines

► Wind turbines have been the fastest growing but PV will come

► Wind turbine technology – better performance

- Full scale power electronics

- New generator concepts (e.g. PM, gearless)

- Larger size – lower cost per kWh

► A university-industry collaborated center has been established to advance

the research progress in reliability of power electronic, especially for the

applications in renewable energy systems.

Power Electronics

enabling wind power into an intelligent grid


References 1. H. Wang, M. Liserre, and F. Blaabjerg, “Toward reliable power electronics - challenges, design tools and opportunities,” IEEE Industrial

Electronics Magazine, Jun. 2013 (in press).

2. H. Wang, F. Blaabjerg, and K. Ma, “Design for reliability of power electronic systems,” in Proceedings of the Annual Conference of the IEEE

Industrial Electronics Society (IECON), 2012, pp. 33-44.

3. F. Blaabjerg, Z. Chen, and S. B. Kjaer, “Power electronics as efficient interface in dispersed power generation systems,” IEEE Trans. on Power

Electron., vol. 19, no. 4, pp. 1184-1194, Sep. 2004.

4. F. Blaabjerg, M. Liserre, and K. Ma, “Power electronics converters for wind turbine systems,” IEEE Trans. on Ind. Appl., vol.48, no.2, pp.708-

719, Mar-Apr. 2012.

5. S. B. Kjaer, J. K. Pedersen, and F. Blaabjerg, “A review of single-phase grid connected inverters for photovoltaic modules,” IEEE Trans. on Ind.

Appl., vol. 41, no. 5, pp. 1292-1306, Sep. 2005.

6. K. Ma, F. Blaabjerg, and M. Liserre, “Thermal analysis of multilevel grid side converters for 10 MW wind turbines under low voltage ride

through”, IEEE Trans. Ind. Appl., vol. 49, no. 2, pp. 909-921, Mar./Apr. 2013.

7. K. Ma, M. Liserre, and F. Blaabjerg, “Reactive power influence on the thermal cycling of multi-MW wind power inverter”, IEEE Trans. on Ind.

Appl., vol. 49, no. 2, pp. 922-930, Mar./Apr. 2013.

8. C. Busca, R. Teodorescu, F. Blaabjerg, S. Munk-Nielsen, L. Helle, T. Abeyasekera, and P. Rodriguez, “An overview of the reliability prediction

related aspects of high power IGBTs in wind power applications,” Journal of Microelectronics Reliability, vol. 51, no. 9-11, pp. 1903-1907, 2011.

9. E. Koutroulis and F. Blaabjerg, “Design optimization of transformerless grid-connected PV inverters including reliability,” IEEE Trans. on Power

Electronics, vol. 28, no. 1, pp. 325-335, Jan. 2013.

10. K. B. Pedersen and K. Pedersen, “Bond wire lift-off in IGBT modules due to thermo-mechanical induced stress,” in Proc. of PEDG’ 2012, pp.

519 - 526, 2012.

11. S. Yang, D. Xiang, A. Bryant, P. Mawby, L. Ran and P. Tavner, “Condition monitoring for device reliability in power electronic converters: a

review,” IEEE Trans. Power Electron., vol. 25, no. 11, pp. 2734-2752, Nov., 2010.

12. M. Pecht and J. Gu, “Physics-of-failure-based prognostics for electronic products,” Trans. of the Institute of Measurement and Control , vol. 31,

no. 3-4, pp. 309-322, Mar./Apr., 2009.

13. Moore, L. M. and H. N. Post, “Five years of operating experience at a large, utility-scale photovoltaic generating plant,” Progress in

Photovoltaics: Research and Applications 16(3): 249-259, 2008.

14. Reliawind, Report on Wind Turbine Reliability Profiles – Field Data Reliability Analysis, 2011.

15. D. L. Blackburn, “Temperature measurements of semiconductor devices - a review,” in Proc. IEEE Semiconductor Thermal Measurement and

Management Symposium, pp. 70-80, 2004.

16. Avenas, Y., L. Dupont and Z. Kahatir, “Temperature measurement of power semiconductor devices by thermo-sensitive electrical parameters -

A review,” IEEE Trans. Power Electron., vol. 27, no. 6, pp. 3081-3092, Jun., 2010.

17. K. Kriegel, A. Melkonyan, M. Galek, and J. Rackles, “Power module with solid state circuit breakers for fault-tolerant applications,” in Proc. of

Integrated Power Electronics Systems (CIPS), pp. 1-6, 2010.

18. ZVEL, Handbook for robustness validation of automotive electrical/electronic modules, Jun. 2008.

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