technical challenge of lightning protection for wind power ... · 18th november,2008 technical...

18th November,２００８

Technical Challenge of Lightning Protection for Wind Power Generation

Takayuki Nakamoto,Hiroshi MoritaKinden Corporation

1

Contents

1.Situation of wind power generation in the worldwide and domestic

2.Lightining strokes to the wind power generation2-1.Lightning in Japan2-2.Lightning damages on wind power

generation in Japan3. Observation and analysis of lightning

stroke to the wind power generation3-1.Observation3-2.Analysis and Result

4. Technical challenge of Lightning protection for wind power generation

5. Planning of further reserch

2

1.Situation of wind power generation in the

worldwide and domestic

3

1.Situation of wind power generation in theWorldwide and domestic

22202540288035904820607076401015013930

1845024930

32040

39430

47570

59250

74330

93880

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000[MW]

19911992199319941995199619971998199920002001200220032004200520062007

[Y ear]F ig .1　Past record as electric power supply from windpower generation in the world

4


22250

16970

15150

7840

5910

3120 2730 2430 2370 2150 1850 1750 1670

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

22000

24000[MW]

Germ

any

US

A

Spai

n

India

Chi

na

Den

mar

k

Ital

y

Uni

ted

Fra

nce

Port

uga

l

Can

ada

Neth

erlan

ds

Jap

an

F ig2 The amount of installation of windpower generation in each country

<At the end of 2007>　　　　　　　　　( )G rowth rate from previousquaterG ermany : 22,250MW (7.9% )US A : 16,970MW (45.1% )S pain : 15,150MW (30.4% )India : 7,840MW (25.1% )C hina : 5,910MW (127.7% )J apan : 1,670MW (12.1% )←The thirteenthlargest in the world

5


10 14 22 38 83144

313

464

681

927

1078

1491

1675

0

500

1000

1500

2000[MW]

19911992199319941995199619971998199920002001200220032004200520062007

[Y ear]F ig3　Increase of ins tallation of windpower generation in J apan

At the end of March in2008E lectricity generated:1,675MW

6


F ig4　Market share of windturbine manufacturer in the world

Vestas(Denmark),31.4%

Enercon(Germany),14.6%

Gamesa(Spain),14.2%

GE(USA), 13.8%

Siemens(Denmark),7.4%

Suzlon(India), 5.0%

Nordex(Germany),4.1%

Acciona(Spain),1.8%

Goldwind(China),1.5%

Sinovel(China), 0.8%

Others, 12.0%

7

2.Lightning strokes to the wind power generation

8

References cited “Inspection of countermesure for lightning against wind power generation”published by NEDO in 2006

Number of lightning （Summer season）

2-1.Lightning in Japan

Number of lightning （Winter season）

6～times/km2a year

4～6times/km2 a year



Summer season

Winter season

0.6～0.8times/km2 a year

0. 4～0.6times/km2 a year

0. 2～0.4times/km2 a year

0～0.2times/km2 a year

9

Item Summer season lightning

Winter season lightning

Altitudecloud base 12000m～ 300m～

Polar character Negative(95%) Positive(1/3)

Progressing direction

of dischargingDown side Upside

Crest value of current ～250kA ～150kA＜

Duration of Wave tale ～250μs ～10000μs

Discharging mass ～90C ～3000C


References cited “Inspection of countermeasure for lightning against wind power generation”published by NEDO in 2006

10

2-1.Lightning in JapanThe lightning in Japan Sea area has a tendency to be upward discharge

Downward discharge Upward discharge

11Quote Met office website




Cloud streak

31

Quote Met office website


32



33



34


ground

+ +

－－

Strong windfrom Siberia

ocean

rising air

－－ + +

Discharge with minus

Discharge With plus

Features of lightning inwinterseason along Japan Sea

2-2.Lightning damages on wind power generation in Japan

Lightning stroke

Damage on electrical equipment

35

Bｌade broken

Damage on control device

36

3.Observation and analysis of lightning stroke to the wind

power generation

Joint study with Doshisha university

37

3-1.Observation

Experiment facility

38

3-1.Observation

NO.2WT

NO.10WT

NO.9WT

NO.8WT

NO.7WT

NO.1WT

NO.3WT

NO.4WT

NO.5WT

NO.6WT

Substation

22kV switchgear

Earthingresistance

1.0Ω

Earthingresistance

1.2Ω

1.8Ω 1.9Ω 1.9Ω 1.0Ω 1.9Ω

1.6Ω 4.2Ω 3.8Ω

Earthingresistance

8.7Ω

Earthingresistance

0.2Ω

Grid

150㎜2-1C×3

95㎜2-1C×3

240㎜2-1C×3

240m0.02Ω

300m0.02Ω

240m0.02Ω

60m0.01Ω

420m0.03Ω

300m0.02Ω

900m0.06Ω

480m0.03Ω

660m0.04Ω 960m

0.06Ω

5830m0.35Ω

Grounding grid

39

Tide mark

Blade

Nacelle

Hub center

Tower

Recorded area

Monitoring camera

3-1.Observation

40

Rogowski coilFrequency：10Hz～200kHzDiameter：4.5m，0.4m×4

Digital oscilloscopeNumber of channel：5

Degradation ability：12bitSampling period：0.1μs

3-1.Observation

3-2.Analysis and result

Visual data of Upward lightning 1

0 / 30 sec3-2.Analysis and result

1 / 30 sec

Elongation of lightning leader


3 / 30 sec

Branching leader


5 / 30 sec

Elongatation


Discharge


Visual data of Upward lightning 2


0 / 30 sec

First lightning stroke（negative）


1 / 30 sec

Elongate leaderin the distance


3 / 30 sec

Second stroke（positive）


56

Most of the lightning strikes to the edge of blade receptor.

Some lightning discharges along the creepage surface


0 20 40 60 80 100 120-30

-20

-10

0

10

20

30

40

50

60

time [ms]

curr

ent

[kA

]

i1i2i3i4i5

57

i1

i2

i3

i4

i5 ×４

Waveform of lightning current


58

10-2

10-1

100

101

102

10-3

10-2

10-1

100

frequency [kHz]

ratio

i2i3i4i5

Current Amplitude-frequency characteristic


59

4.Technical challenge of lightning protection for wind power generation


Lightning strike point

60

Lightning current discharging root

61

Earth connection bar

Earthing wire between tower and ground

Tower

Lightning current discharge root


62

Cat whisker


Pile foundation Earthing from reinforcementrth

in foundation

Mesh earth

Utilize foundation structure as earthing

63

Earthingresistance

1.0Ω

Earthingresistance

1.2Ω

1.8Ω 1.9Ω 1.9Ω 1.0Ω 1.9Ω

1.6Ω 4.2Ω 3.8Ω

Earthingresistance

8.7Ω

Earthingresistance

0.2Ω

NO.2WT

NO.10WT

NO.9WT

NO.8WT

NO.7WT

NO.1WT

NO.3WT

NO.4WT

NO.5WT

NO.6WT

Substation

22kV switchgear

Grid

150㎜2-1C×3

95㎜2-1C×3

240㎜2-1C×3

240m0.02Ω

300m0.02Ω

240m0.02Ω

60m0.01Ω

420m0.03Ω

300m0.02Ω

900m0.06Ω

480m0.03Ω

660m0.04Ω 960m

0.06Ω

5830m0.35Ω

Grounding grid

Cable － 22kV XLPE/AWA

Conductor

Conductor screenInsulation

Insulation screenMetalic screenBinder tape

Separation sheathWire armourBinding tape

Outer sheathUtilize alminum wire as

insulated wire connecting


64

Traditional modelLightning

ΔU

Electrical potential


Switch gear and transformer are installed outside of tower

65

Modified model Lightning

Potentionalequalization

Electrical potential


66

Optical fiber cable(non metalic)

Power lineCommunication cable

ＳＰＤ

Electrical equipmentControl &

communication equipment


67

5. Planning of further 5. Planning of further reserchreserch

68

5.Planning of further reseachMeasurement and Analysis on selected Subjects .

・Lightning surge to the transformer⇒Measure the of over voltage at transformer

22kV/575VTransformer

1800kVA

From windpower generation

oscilloscope UPSShild transformer200/100V500VA

AC230V

LBS

Choppedwave

24kVLBS24kV

LBS24kV

SurgeChopped

wave SurgeFrom grid

technical challenge of lightning protection for wind power ... · 18th november,2008 technical...

Documents