analysis and testing of small wind turbines connected to weak and autonomous grids luis cano luis m....

ANALYSIS AND TESTING OF SMALL WIND TURBINES

CONNECTED TO WEAK AND AUTONOMOUS GRIDS

LUIS CANO

LUIS M. ARRIBAS

CIEMAT (Spain)

EWEC 2006, Athens

INDEX

• Background

• SWT connected to the grid:

o State of the art

– SWT

– Inverters - Measurements

o Standards revision

• SWT connected to Autonomous systems.

o DC-coupled

– Case study: CICLOPS system.

o AC-coupled

– Case study: HYBRIX system.

EWEC 2006, Athens

BACKGROUNDS

General view: phase I

100 m Mast

SWT Measuring

EWEC 2006, Athens

BACKGROUNDS

General view: phase II

SWT Measuring

Meteorological

Masts

EWEC 2006, Athens

BACKGROUNDS

CIEMAT’s TEST FACILITY:

• Power Performance Tests. (IEC 61400-12)

• Noise Emission Measurement (IEC 61400-11)

• Safety and Function Tests (IEC WT 01)

• Measurements of grid connected SWT (IEC 61400-21)

• Duration Tests (IEC WT 01)

• Other Test

-Generators performance

-Blade Test

EWEC 2006, Athens

SWT connected to the grids: State of the art

CONNECTION TOPOLOGIES:

1

RECTIFIER CHOPPER INVERTER

2

GRID (Optional)

GRID

EWEC 2006, Athens

SWT connected to the grids: State of the art

Principal SWT connected to grids in Europe (I)

MANUFACTURER COUNTRY SWTRATED

POWER (kW) CONVERTERINVERTER orCONVERTER

WT600 0.6 1 Windy BoyPROVEN UK WT2500 2.5 1 Windy Boy

WT6000 6 1 Windy BoyWT15000 15 1 Windy BoyInclin 250 0.25 1 BORNAYInclin 600 0.6 1 BORNAY

BORNAY Spain Inclin 1500 neo 1.5 1 BORNAYInclin 3000 neo 3 1 BORNAYInclin 6000 neo 6 1 BORNAY

Whisper 100 0.9 1 Windy BoySOUTHWEST USA Whisper 200 1 1 Windy Boy

Whisper 500 3 1 Windy BoyGEV 5/5 o 6/5 5 2 Vergnet

VERGNET France GEV 7/10 10 2 VergnetGEV 10/20 20 2 VergnetGEV 15/60 60 2 Vergnet

ROPATEC Italy WRE.030 2.5 1 Aurora or SMDWRE.060 5 1 Aurora or SMD

WT Scirocco 5 1 MWIEOLTEC France WT Wind Runner 25 1 Ingecon Hybrid

WT Cinook 75 1 Ingecon HybridWINDECO Spain VENTO 5000 5 1 Ingecon Wind

Source: Manufacturer webpages

EWEC 2006, Athens

SWT connected to the grids: State of the artPrincipal SWT connected to grids in Europe (II)

MANUFACTURER COUNTRY SWTRATED

POWER (kW) CONVERTERINVERTER orCONVERTER

SOLENER Spain Velter II 2 1 LenzeVelter XV 15 1 LenzeEspada 0.8 1 Sun ProfiPassaat 1.4 1 Sun Profi

FORTIS The Netherlands Montana 5.8 1 Sun ProfiAlize 10 1 Sun Profi

Boreas 20-30 1 Sun ProfiAVENTA Switzerland AV-7 6.5 1 UnknownAIRCON Germany Aircon 10 9.8 1 Unknown

FUHRLANDER Germany FL 30 30 2 FuhrlanderFL 100 100 2 Fuhrlander

INVENTUS Germany Inventus 6 6 2 InventusWINDTOWER Germany WT 10P 10 1 Unknown

WT 50 50 1 UnknownACSA Spain ACSA-LMW-1003 1 1 Unknown

BERGEY USA BWC Excel-S 10 1 Gridtek 10Butterfly 1K 1.5 1 Unknown

ENERGOTECH Greece Butterfly 3K 3.5 1 UnknownButterfly 6K 7 1 Unknown

EWSI USA EW15 50 2 EWSIAERODYN and SMA Germany Aerosmart 5 5 2 SMA

Source: Manufacturer webpages

EWEC 2006, Athens

SWT connected to the grids: State of the art

Inverters

• 6 THYRISTOR BRIDGE INVERTER

R S T

DC

Output Current in 6 pulse-thyristor inverter

-40.00

-30.00

-20.00

-10.00

0.00

10.00

20.00

30.00

40.00

0 100 200 300 400 500 600 700 800 900 1000

Cu

rren

t (A

)

EWEC 2006, Athens

SWT connected to the grids: State of the art

Inverters

• 6 IGBT PWM INVERTER

R

DC

S T

Output current in 6 IGBT PWM Inverter

-400

-300

-200

-100

0

100

200

300

400

1

12

23

34

45

56

67

78

89

10

0

11

1

12

2

13

3

14

4

15

5

16

6

17

7

18

8

19

9

21

0

22

1

23

2

24

3

25

4

26

5

27

6

28

7

29

8

30

9

32

0

33

1

34

2

35

3

36

4

Vo

lta

ge

(V

)

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

Cu

rre

nt

(A)

Voltage (V) Current (A)

EWEC 2006, Athens

SWT connected to the grids: State of the artInverters. Case: 6 IGBT PWM INVERTER

Uthd, Ithd and Pthd in a 6 GBT PWM inverter

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

20.00

0

50

0

10

00

15

00

20

00

25

00

30

00

35

00

40

00

45

00

50

00

Power (W)

Ith

d,

Uth

d a

nd

Pth

d (

%)

Inverter Current and Voltage Waves

-400

-300

-200

-100

0

100

200

300

400

1 11 21 31 41 51 61 71 81 91 101

111

121

131

141

151

161

171

181

191

201

211

221

231

241

Vo

ltag

e (V

)

-8

-6

-4

-2

0

2

4

6

8

Cu

rren

t (A

)

Voltage (V) Current (A)

EWEC 2006, Athens

•Measurements of grid connected SWT

Data of SWT measured. Case of a 5kW 6 IGBT PWM inverter Current Harmonics in a Sudden Connection

0.0

0.2

0.4

0.6

0.8

1.0

1.21 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

Harmonic

Cu

rren

t H

arm

on

ics

(%)

Connection current (A) 0.4 kW Connection current (A) 3kW

EWEC 2006, Athens

•Standards revision. IEC 61000 standards on EMC:

3-2: 2001. “Limits for harmonic current emissions (equipment input current up to and including 16 A per phase).”

3-3: 1997. “Limitation of voltage fluctuation and flicker in low-voltage supply systems for equipment with rated current of 16 A.”

4-7: 2004. “Harmonics and Interharmonics Measurements and Instrumentation for Power Supply Systems”

4-11: 2004. “Voltage Dips, Short Interruptions, and Voltage Variations Immunity Test”4-15: 2004. “Flickermeter”

6-3 Ed 2 (RDIS): 2004. “Generic standards -Emission standard for residential commercial and light industrial environments”

6-4: 2002. “Generic standards -Emission standard for industrial environments”

EWEC 2006, Athens

•Standards revision. Other local Standards.American Standards:UL 1741 Static Inverters and Charge ControllersIEEE 519 Harmonic Control in Electric Power SystemsIEEE 929 Utility interface of PhotovoltaicANSI C62.41, C1, C2 Surge Voltages in Low-Voltage AC Power Circuits

British Connection StandardsGE 59, 83 Embedded Generating Plants, Small-scale generators (up to 16A)

GE 77 Single-phase photovoltaic generators up to 5kVA

German Standards VDE 0126 Automatic Disconnection Facility for PV Installations

OthersKEMA K150 Small Grid-connected Photovoltaic SystemsJIS C 8962 Power Conditioners for Small PV Power Generating Systems ÖNORM/ÖVE 2750 Austrian Guideline - PV Power Generation SystemsNEN1010 Grid-connected PV SystemsAS3000, AS4777 Australian - Connection of Energy SystemsCSA F381 Canadian - Power Conditioning Systems

EWEC 2006, Athens

•SWT connected to Autonomous systems.

Connection Topologies (I): DC-Coupled

Energy Use Energy UseEnergy UseEnergy Use

+-

Rectifier+

Regulator

WindTurbine

BatteryStorage

Back-upGenset

~Stand-alone Inverter

DC Side

AC Side

EWEC 2006, Athens

•SWT connected to Autonomous systems.

Connection Topologies (I): DC-Coupled

•Power electronics • Rectifier (for the SWT)

• DC/DC converter (optional)

• Stand-alone Inverter

• self-commutated

• voltage controlled

• Stabilizing Unit• long-term storage (battery)

• “One-way” converter (inverter)

• Traditional and common way of connection

• Well known (stand-alone systems)

• High quality, relative low price

•PQ dependant on:

• the inverter

• the load

• not on the SWT

Energy Use Energy UseEnergy UseEnergy Use

+-

Rectifier+

Regulator

WindTurbine

BatteryStorage

Back-upGenset

~Stand-alone Inverter

DC Side

AC Side

EWEC 2006, Athens

•DC-Coupled SWT connected to Autonomous systems. Case Study: CICLOPS Project Description

7.5 kW SWT 5 kWp PV array20 kVA Genset595 C10 Battery Storage

EWEC 2006, Athens

•DC-Coupled SWT connected to Autonomous systems. Case Study: CICLOPS Project – Data Logging Description

IFVNREG

VFVNREG

VBAT

IFVREG

ICarga(DC) PCarga(DC)

FREC.AERG.

IBAT

IAS(DC)

IA(AC) VA(AC) TBAT

GP

VV

EWEC 2006, Athens

•DC-Coupled SWT connected to Autonomous systems. Case Study: CICLOPS Project – WT Power Curve

EWEC 2006, Athens

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

%

UhdfIhdfPhdf

•DC-Coupled SWT connected to Autonomous systems. Case Study: CICLOPS Project – Inverter characterization

Harmonic Distortion for orders from 2 to 50 (3400 W resistive load)

-400

-300

-200

-100

0

100

200

300

400

0 2 4 6 8 10 12 14 16 18 20

Time (miliseconds)

Vo

ltag

e (v

olt

s)

-25

-20

-15

-10

-5

0

5

10

15

20

25

Cu

rren

t (A

mp

eres

)

UI

Wave form (3400 W

resistive load)

EWEC 2006, Athens

•DC-Coupled SWT connected to Autonomous systems. Case Study: CICLOPS Project – Inverter characterization

0.0

0.5

1.0

1.5

2.0

2.5

0 500 1000 1500 2000 2500 3000 3500 4000

AC power (W)

% U

thd

an

d I

thd

)

0.000

0.010

0.020

0.030

0.040

0.050

0.060

0.070

0.080

0.090

0.100

% (

Pth

d)Uthd

Ithd

Pthd

Harmonic Distortion for 1 phase (U, I, P) for different resistive loads (cos Φ = 1).

EWEC 2006, Athens

•SWT connected to Autonomous systems.

Connection Topologies (II): AC-Coupled

Energy Use Energy UseEnergy UseEnergy Use

+-

~ Bi-directional

Converter Grid-connected

Inverter

WindTurbine

BatteryStorage

Back-upGenset

AC Side

~

EWEC 2006, Athens

•SWT connected to Autonomous systems.

Connection Topologies (II): AC-Coupled•Power electronics

• Rectifier

• DC/DC converter (optional)

• Inverter (optional)

• Bi-directional converter

• Stabilizing Unit• long-term storage (battery)

• Bi-directional converter

• Recently developed

• AREP Project

• SMA concept technology

•PQ dependant on: • AC coupled devices (including the SWT)

• the inverter

• the load

Energy Use Energy UseEnergy UseEnergy Use

+-

~ ~ Bi-directional

Converter Grid-connected

Inverter

WindTurbine

BatteryStorage

Back-upGenset

AC Side

~

EWEC 2006, Athens

•SWT connected to Autonomous systems.

10 kW Vergnet SWT; 30.8 kW PV array and 20 kVA diesel genset. 3 lead acid batteries (2x2200 Ah, 1x800 Ah, 60 volts)

Case Study: HYBRIX Project Description

Sunny Island Inverters

From “Iberinco desarrolla el sistema híbrido de generación eléctrica aislado Hybrix ”. Infoenergía.com

EWEC 2006, Athens

•SWT connected to Autonomous systems.

Case Study: HYBRIX Project PQ issues - Sunny Island characteristics

Harmonic Distortion

EMC interference

EWEC 2006, Athens

CONCLUSIONS

• Each country has its own Grid-connection standards

• Lack of optimal coupling between the converter and the turbine. (Most of manufacturers buy the inverter and don´t adapted it)

• Except few ones, it´s not easy to know if the inverters fulfilled the standards

• Inverters are carried out for PV market

• Technology is not mature

• Certification in each country is very costly

EWEC 2006, Athens

THANK YOU FOR YOUR ATTENTION!