WINDTEST - NoordzeeWind€¦ · · 2015-07-01Vestas Offshore The Netherlands B.V ... under test...

Power quality measurements on a wind farm of 36xV90-3MW related to the

�IEC 61400-21 First Edition�

Report WT6854/08

Nordzee wind report number OWEZ_R_171_power_quality_16122008

January 2009

WINDTEST Kaiser-Wilhelm-Koog GmbH

Laboratory accredited by DAP Deutsches Akkreditierungssystem

Prüfwesen GmbH according to DIN EN ISO/IEC 17025. The accreditation is valid for the scope

mentioned in the certificate. DPT-PL-1556.01

Power quality measurements on a wind farm of 36xV90-3MW related to

the �IEC 61400-21 First Edition�

Report WT6854/08

Test site: Offshore windfarm Egmond aan Zee (NL)

Customer:

Vestas Offshore The Netherlands B.V

Trawlerkade 54

1976 CB Ijmuiden

The Netherlands

Contractor: WINDTEST Kaiser-Wilhelm-Koog GmbH Sommerdeich 14 b 25709 Kaiser-Wilhelm-Koog

WINDTEST order no. 4250 06 03290 252 Date of order 2006-03-13

Customer order no.

Prepared: Checked:

Dipl.-Ing. Marko Ibsch

(Power Quality Department)

Dipl.-Ing. Kai Nohme

(Power Quality Department,Head of Department)

Kaiser-Wilhelm-Koog, 13th of January 2009

Extracts may be copied from this report only with the written consent of WINDTEST Kaiser-Wilhelm-Koog GmbH. It comprises a total of 100 pages, including appendices.

The results given in this report relate only to the specific wind turbine under test.

WINDTEST Kaiser-Wilhelm-Koog GmbH

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WT6854/08: Power quality measurements on a wind farm of 36xV90-3MW WINDTEST Kaiser-Wilhelm-Koog GmbH

Table of contents 1 Definitions ...................................................................................................................................... 4 2 Scope .............................................................................................................................................. 5 3 General Information....................................................................................................................... 6

3.1 Wind turbine........................................................................................................................... 6 3.1.1 General data ............................................................................................................... 6 3.1.2 Rated data .................................................................................................................. 6

3.2 Test site and grid topography ................................................................................................ 6 3.3 Test equipment ...................................................................................................................... 7 3.4 Test conditions....................................................................................................................... 9

3.4.1 Short circuit power and total harmonic distortion ....................................................... 9 3.4.2 Turbulence intensity ................................................................................................... 9 3.4.3 Voltage fluctuation .................................................................................................... 10 3.4.4 Voltage unbalance factor.......................................................................................... 10 3.4.5 Grid frequency .......................................................................................................... 11

3.5 Used data............................................................................................................................. 12 4 Realisation of the measurements and analysis of the acquired data (with 35 wind turbines

connected).................................................................................................................................... 13 4.1 Power ................................................................................................................................... 13

4.1.1 Maximum permitted power ....................................................................................... 13 4.1.2 Maximum measured power ...................................................................................... 14 4.1.3 Reactive Power ........................................................................................................ 18

4.2 Voltage fluctuations.............................................................................................................. 20 4.3 Harmonics............................................................................................................................ 24

5 Realisation of the measurements and analysis of the acquired data (0-6 m/s) ................... 27 5.1 Power ................................................................................................................................... 27

5.1.1 Maximum measured power ...................................................................................... 27 5.1.2 Reactive Power ........................................................................................................ 31


6 Realisation of the measurements and analysis of the acquired data (6-11 m/s) ................. 40 6.1 Power ................................................................................................................................... 40



7 Realisation of the measurements and analysis of the acquired data (11-16 m/s) ............... 55 7.1 Power ................................................................................................................................... 55



8 Realisation of the measurements and analysis of the acquired data (16-20 m/s) ............... 69 8.1 Power ................................................................................................................................... 69



9 Uncertainty analysis.................................................................................................................... 83 9.1 Estimation of the uncertainties in the power quality measurement ..................................... 83 9.2 Errors due to current transformers....................................................................................... 87 9.3 Errors due to voltage transformers ...................................................................................... 87 9.4 Errors due to the measurement wiring................................................................................. 87

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9.5 Errors due to the isolating amplifier ..................................................................................... 87 9.6 Errors due to the A/D � converter ........................................................................................ 87 9.7 Errors due to the sampling rate and software...................................................................... 87

9.7.1 Power measurement ................................................................................................ 87 9.7.2 Flicker measurement ................................................................................................ 87 9.7.3 Sampling rate............................................................................................................ 87

10 Summary....................................................................................................................................... 88 10.1 35 connected turbines.......................................................................................................... 88 10.2 All measurement data with a mean wind speed range from 0 m/s to 6 m/s........................ 89 10.3 All measurement data with a mean wind speed range from 6 m/s to 11 m/s...................... 90 10.4 All measurement data with a mean wind speed range from 11 m/s to 16 m/s.................... 91 10.5 All measurement data with a mean wind speed range from 16 m/s to 20 m/s.................... 92

11 References ................................................................................................................................... 93 12 Appendix ...................................................................................................................................... 94

12.1 Manufacture�s certificate ...................................................................................................... 95 12.2 Calibration certificate of the DEWE800 ............................................................................... 96 12.3 Calibration certificate of the DEWE-RACK 16 ..................................................................... 97 12.4 Calibration certificates of the current transformers.............................................................. 98

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1 Definitions Pn Rated active power of the WT specified by the manufacturer

Sn Measured apparent power at nominal power and nominal voltage of the WT

vn Wind speed, at which the nominal power of the WT is reached, specified by the manufacturer

Un Nominal phase-to-phase voltage of the WT

In Rated current of the WT at rated apparent power at nominal voltage

Sk Short-circuit apparent power of grid

Sk, fic Short-circuit apparent power of the fictitious grid

UnG Nominal phase-to-phase voltage of the WT

I (I1, I2, I3) r.m.s. current (of phase 1, phase 2, phase 3)

U (U1, U2, U3) r.m.s. voltage (of phase 1, phase 2, phase 3)

U12, U23, U31 r.m.s. phase-to-phase voltage

Usym Voltage unbalance factor: Ratio of the negative sequence component of voltage to the positive sequence component of voltage

Ufic One period r.m.s. value of the phase-to-neutral voltage on the fictitious grid during the switching operation

Plt Longterm flicker emission

Pst, fic Flicker emission from the WT on the fictitious grid

Tp Measurement period, long enough to ensure that the transient of the switching operation has abated, though limited to exclude possible power fluctuations due to turbulence

Xk Network short-circuit reactance

Rk Network short-circuit resistance

ψk Phase angle of network short circuit impedance

ψk = arctan (Xk / Rk)

c(ψk) Flicker coefficient for continuous operation is a normalised measure of the flicker emission during continuous operation of the WT

ku(ψk) The voltage change factor is a measure of the voltage change due to a switching operation of the WT.

kf(ψk) The flicker step factor is a normalised measure of the flicker emission due to a single switching operation of the WT.

THD Total harmonic current distortion

Turbulence intensity Ratio of the wind speed standard deviation to the mean wind speed, set of measured samples of wind speed and taken over a specified period of time, normally over a period of 10-min

WT Wind turbine

fg Fundamental grid frequency (Hz)

EMC Electromagnetic compatibility

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2 Scope WINDTEST Kaiser-Wilhelm-Koog GmbH (WINDTEST) was contracted by Vestas to carry out power quality measurements on the offshore wind farm Egmond aan Zee of 36xV90-3MW in the North Sea, off the coast Egmond aan Zee, Netherlands, related to the �IEC 61400-21: The measurements the offshore wind farm were done on the onshore substation in Wijk aan Zee, Netherlands. Measurement and assessment of power quality characteristics of grid connected wind turbines� [1]. Due to the scope of the guideline of single turbines the measurements were made deviant. As far as reasonable the measurement procedure was adapted to the measurement of a windfarm.

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3 General Information

3.1 Wind turbine The wind turbines (WTs) under test were 36 Vestas V90-3MW with the following technical specifications:

3.1.1 General data

Wind turbine type ................................................................................................ horizontal axis Number of blades ................................................................................................ 3 Rotor diameter..................................................................................................... 90 m Hub height ........................................................................................................... 79.45 m Power control ...................................................................................................... pitch, variable speed Generator type and rating ................................................................................... asynchronous,3060 kW Frequency converter and rating .......................................................................... VESTAS, 328 kVA

3.1.2 Rated data

Rated active power.............................................................................................. 3060 kW Rated wind speed................................................................................................ 15 m/s Rated apparent power......................................................................................... 3125 kVA Rated current....................................................................................................... 1766 A Rated voltage ...................................................................................................... Stator: 1000 V ............................................................................................................................. Rotor: 400 V Rated frequency .................................................................................................. 50 Hz Further details can be found in the manufacturer�s certificate which is included in appendix 12.1 to this report. Serial numbers of all the relevant components of the electrical system are also given in appendix 8.2.

3.2 Test site and grid topography The test site is located in the North Sea, off the coast Egmond aan Zee, Netherlands. The location is marked in map 3.2.1. The measurements of the offshore farm were done in the onshore substation. The site has three sections each with 12 turbines of the type V90-3MW. The measurements were taken at the 3 medium voltage sections and at the high voltage level.

Map 3.2.1: Location of the test site in the Netherlands

Wind farm

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3.3 Test equipment The recorded signals and transducers are listed in table 3.3.1.

Measured signal Description of transducer

Designation / WINDTEST-

Inventory No./ serial No.

Measurement accuracy

Scale factor

3 phase currents 34kV Level A

current probes (Chauvin Arnoux Ampflex A100)

I1 WT 300118806

I2 WT 300118906

I3 WT 300130607

Class 1 1000 A / 2 V

3 phase-to-phase voltages

34 kV Level A

voltage transformers

(Vestas)

U1 F455 U2 F455 U3 F455

transducer provided by the

customer* 34 kV / 100 V

3 phase currents 34kV Level B


I1 WT 300081104

I2 WT 300081204

I3 WT 300075503

Class 1 1000 A / 2 V


34 kV Level B


(Vestas)

U1 F455 U2 F455 U3 F455



3 phase currents 34kV Level C


I1 WT 300118306

I2 WT 300119208

I3 WT 300119106

Class 1 1000 A / 2 V


34 kV Level C


(Vestas)

U1 F455 U2 F455 U3 F455



3 phase currents 150kV Level


I1 WT 300075603

I2 WT 300119006

I3 WT 300081004

Class 1 1000 A / 2 V


150 kV Level


(Vestas)

U1 F61 U2 F61 U3 F61



wind speed Metmast n.a. transducer

provided by the customer

4 mA to 20 mA corresponds to

0 to 50 m/s

3 * number of turbines

Wind farm controller n.a.


customer

4 mA to 20 mA corresponds to 0 to 12 turbines

Table 3.3.1: Sensors and transducers * For these transformers, the customer couldn�t provide calibration certificates.

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Generally all measurement systems comprise the following components:

• Signal transducers

• Isolating amplifiers

• Antialiasing-filters

• A/D-converter

The measurement systems used is described in table 3.3.2 following:

Manufacturer System A/D-converter Filter Isolating amplifier

DEWETRON

(for IEC 61400-21)

DEWE 800 + DEWE Rack 16

(WT300117906) (WT300103405)

DEWE-ORION-1624

24 bit

fmax = 2.8 MHz

eligible: 20, 200, 2000, 10,000,

and 20,000 Hz

DEWETRON (DAQP-DMM,

DAQP-V)

DEWETRON

(for EN 50160)


(provided by DEWETRON)

DEWE-ORION-1624

24 bit

fmax = 2.8 MHz

eligible: 20, 200, 2000, 10,000,

and 20,000 Hz

DEWETRON (DAQP-DMM,

DAQP-V)

Table 3.3.2: Measurement system We are able to provide more detailed specifications of the measurement system on request. The following software was used for measurement and analysis:

Name Supplier Use

DEWESoft Version 6.3.2 b2 DEWETRON measurement data acquisition

WINDTEST Data acquisition IEC (version 4.1) WINDTEST measurement data acquisition

WINDTEST Analysis Software IEC (version 2.6) WINDTEST computation and analysis

FAMOS IMC computation and analysis

Table 3.3.3: Software

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3.4 Test conditions The measurements took place from 2007-05-11 to 2008-08-07 at Ijmuiden. The wind conditions during this time period were suitable for testing the full power range and met the conditions of the IEC 61400-21 [1].

3.4.1 Short circuit power and total harmonic distortion

The short circuit apparent power at the point of connection to the medium voltage network shall be 50 times the apparent power at Pmc (maximum permitted power) of the assessed wind turbine according for the IEC 61400-21 [1]. The value for the short circuit power was not provided by the manufacturer.

Moreover, the total harmonic distortion (THD) of the voltage including all harmonics up to the order of 50 shall be less than 5 % measured as 10-min-average data at the wind turbine terminals while the wind farm is not connected to the grid. Before the start of the measurements the total harmonic distortion of the voltage was determined by means of measurement to be less than 0.56 %.

3.4.2 Turbulence intensity

The turbulence intensity was determined by means of measurements using the met mast and is graphically represented in figure 3.4.1. The measurements of the windspeed were done on an external measurement mast. For this measurement the results range from 8 % to 16 %. According to the IEC only data may be taken in account where the turbulence intensity lies between 8 % and 16%. In this case the raw data were not filtered dependant on turbulence intensity, as the effect of the turbulence intensity on the measurement results is regarded as being insignificant.

Turbulence_intensity upper_limit lower_limit

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

15.0

15.5

16.0

16.5

17.0%

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110

MW Figure 3.4.1: Turbulence intensity during the measurement period against active power

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3.4.3 Voltage fluctuation

According to the IEC the voltage shall be within ± 5% of its nominal value measured as 10-min-average data at the wind turbine terminals. Figure 3.4.2 shows the fluctuation of the 10-min-average values of the voltage around the rated phase-to-neutral voltage of 86.6 kV. Some values were out of the limits. These datasets have been excluded of the analysis.

U_L1 U_L2 U_L3 lower_limit upper_limit

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

8

9

10

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110

MW Figure 3.4.2 Voltage fluctuation during the measurement period against active power

3.4.4 Voltage unbalance factor

The voltage unbalance factor shall be less than 2 % measured as 10-min-average data at the turbine terminals. For this measurement there was no considerable voltage unbalance factor occurring in the measurement period.

Usym

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

0.11

0.12

0.13

0.14

0.15

0.16

0.17

0.18

0.19

0.20%

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110

MW Figure 3.4.3: Voltage unbalance factor during the measurement period against active power

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3.4.5 Grid frequency

The measured grid frequency as 0.2-s-average values should be within ±1 % of the nominal frequency and the rate of change of the measured grid frequency as 0.2-s-average data should be less than 0.2 % of the nominal frequency per 0.2 s.

f_upper_limit f_lower_limit f_max f_min

49.049.149.249.349.449.549.649.749.849.950.050.150.250.350.450.550.650.750.850.951.0

Hz

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110

MW Figure 3.4.4: Frequency values during the measurement period against active power

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The grid frequency change should be lower than 0.2 %. All of the meassured values were within this limit (see figure 3.4.5).

f_change_max f_change_upper_limit

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50%

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110

MW Figure 3.4.5: Change of the grid frequency during the measurement period against relative active

power

3.5 Used data The analysis of the measured datasets is divided in two parts: The first part (chapter 4) includes the datasets which were recorded when only 35 wind turbines were connected. The number of 35 was choosen, because this is the highest number of continuously connected turbines. The second part (chapter 5-8) includes all measured datasets which fullfill the test conditions according to the IEC 61400-21. The flicker analysis of these datasets is subdivided in four different bands of wind speed:

• 0-6 m/s • 6-11 m/s • 11-16 m/s • 16-20 m/s

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4 Realisation of the measurements and analysis of the acquired data (with 35 wind turbines connected)

4.1 Power The following specifications are valid for this subsection, as mentioned in table 4.1.1.

Measurement Period System Average period

Number of measured

values

Sampling rate

Reactive power 2007-05-11 to 2008-08-07


(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

243

(3-phase) 4kHz

Power peaks 2007-05-11 to 2008-08-07


(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

243

(3-phase) 4 kHz

Table 4.1.1: Specifications of power measurement

4.1.1 Maximum permitted power

The maximum permitted power was provided by the manufacturer and is given in table 4.1.2 together with the ratio of this to the nominal output power of the turbine.

Pmc [kW] 105,000

pmc =Pmc/Pn 1.00

Table 4.1.2: Maximum permitted power, absolute and relative values

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4.1.2 Maximum measured power

The maximum power values relating to the different averaging periods were derived from 10-minute-data-sets. For this calculation, only data collected during the continuous operation of the wind turbine were taken into account. The resulting distribution can be found in table 4.1.3.

BIN-No Wind speed range Number of data sets

1 0 m/s to 0.5 m/s 0

2 0.5 m/s to 1.5 m/s 0

3 1.5 m/s to 2.5 m/s 0

4 2.5 m/s to 3.5 m/s 0

5 3.5 m/s to 4.5 m/s 5

6 4.5 m/s to 5.5 m/s 38

7 5.5 m/s to 6.5 m/s 30

8 6.5 m/s to 7.5 m/s 52

9 7.5 m/s to 8.5 m/s 35

10 8.5 m/s to 9.5 m/s 32

11 9.5 m/s to 10.5 m/s 16

12 10.5 m/s to 11.5 m/s 10

13 11.5 m/s to 12.5 m/s 6

14 12.5 m/s to 13.5 m/s 5

15 13.5 m/s to 14.5 m/s 8

16 14.5 m/s to 15.5 m/s 6

17 15.5 m/s to 16.5 m/s 0

Table 4.1.3: Number of 10-minute-average data sets

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Figure 4.1.1 shows all the 600-second-average active power values plotted against wind speed.

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100MW

4 6 8 10 12 14 16 18

m/s Figure 4.1.1: 600-second-average values of active power vs. wind speed

The wind speed signal of the met mast were aquired in front of the wind farm in the main wind direction so were some wind shadow effects in other directions. That�s why there are some power values with lower windspeed. The maximum of all of these 600-second-average active power values, P600, together with the ratio of this to the nominal output power of the turbine is given in table 4.1.4.

P600 [kW] 99,647.3

p600 =P600/Pn 0.95

Table 4.1.4: Maximum 600-second-average of active power

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0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100MW

4 6 8 10 12 14 16 18


The maximum of all of these 60-second-average active power values, P60, together with the ratio of this to the nominal output power of the turbine is given in table 4.1.5.

P60 [kW] 99,841.8

p60 =P60/Pn 0.95

Table 4.1.5: Maximum 60-second-average value of active power

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Figure 4.1.3 shows all the 0.2-second-average active power values plotted against wind speed.

05

101520253035404550556065707580859095

100105

MW

4 6 8 10 12 14 16 18

m/s Figure 4.1.3: 0.2-second-average values of active power vs. wind speed

The maximum of all of these 0.2-second-average active power values, P0.2, together with the ratio of this to the nominal output power of the turbine is given in table 4.1.6.

P0.2 [kW] 100,580.4

p0.2 =P0.2/Pn 0.96

Table 4.1.6: Maximum 0.2-second-average value of active power

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4.1.3 Reactive Power

For the calculation of the reactive power, only data acquired during the continuous operation of the wind turbine were utilised. The 10-minute-average data were classified using the method of bins. The data used in the calculation are summarised in the previous table 4.1.3. The results are listed in table 4.1.7 below.

Output power [% of Pn] Number of data sets Active power [kW] Reactive power [kvar]

0..10 44 6235.3 5813.3

10..20 28 15040 5236.5

20..30 30 25602.8 4151.7

30..40 23 36148.1. 2507.5

40..50 46 48158.9 40.6

50..60 36 57144 -2378.8

60..70 14 67533.5 -5666.4

70..80 7 77790.8 -9621.1

80..90 5 88746.9 -14446

90..100 10 96858.3 -17739.8

100..110 0 0 0

Table 4.1.7: Reactive power for the different power classes The following three graphs show the relationship between reactive and active power represented by 10-minute averages, 1-minute averages and 0.2-second averages respectively. The first graph, figure 4.1.4, was used to determine the rated reactive power at rated active power, i.e. at P/Pn=1 (see section 3.1.2 of this report �Rated data�).

-20.00

-18.00

-16.00

-14.00

-12.00

-10.00

-8.00

-6.00

-4.00

-2.00

0.00

2.00

4.00

6.00

8.00Mvar

0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900 1.000

P/Pn Figure 4.1.4: Reactive power vs. relative active power (10-minute-average values)

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-20.00

-18.00

-16.00

-14.00

-12.00

-10.00

-8.00

-6.00

-4.00

-2.00

0.00

2.00

4.00

6.00

8.00Mvar

0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900 1.000

P/Pn Figure 4.1.5: Reactive power vs. relative active power (60-second-average values)

-20.00

-18.00

-16.00

-14.00

-12.00

-10.00

-8.00

-6.00

-4.00

-2.00

0.00

2.00

4.00

6.00

8.00Mvar

0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900 1.000

P/Pn Figure 4.1.6: Reactive power vs. relative active power (0.2-second-average values)

The values for �Reactive power at Pmc�, �Reactive power at P60� and �Reactive power at P0.2� given in table 4.1.8 are derived from the data represented in the three previous graphs, i.e. figure 4.1.4, figure 4.1.5 and figure 4.1.6.

Reactive power at Pmc [kvar] -19008.8

Reactive power at P60 [kvar] -19026.7

Reactive power at P0.2 [kvar] -19615.4

Table 4.1.8: Reactive power at different maximum power peaks

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4.2 Voltage fluctuations The specifications given in table 4.2.1 are valid for the following subsections. Only data associated with the continuous operation of the wind turbine were taken into account for the evaluation of flicker.

Type of measurement

Measurement period System Averaging

period

Number of measured

values

Sampling rate

Flicker 2007-05-11 to 2008-08-07

DEWE 800 + DEWE Rack 16 10 min

243

(3 phase) 4 kHz

Table 4.2.1: Specification of the flicker measurement To determine the flicker short term values Pst, a single-phase network which is modelling a fictitious grid with the following parameters was used:

• Un = 150 kV

• Sk,fic = 20 * Sn = 20 * 35 * 3 MVA = 2,1 GVA

• ψk = 30°, 50°, 70°, 85°

Using network modelling, the measured line current and the measured star voltage, a flicker burdened voltage was calculated for each line and for the four above mentioned angles ψk. These voltages comprise the input of the flicker algorithm according to IEC 61000-4-15 [2]. The result is a short term flicker value Pst. Using the above mentioned method Pst-values were determined for a power range which corresponds to a wind speed range from cut-in wind speed up to 15 m/s. The following four figures show the Pst values for the individual grid impedance angles against wind speed.

0.01000

0.01500

0.02000

0.02500

0.03000

0.03500

0.04000

0.04500

0.05000

0.05500

0.06000

0.06500

0.07000

0.07500(Pst)

4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00

m/s Figure 4.2.1: Short term flicker values (Pst) for the grid impedance angle of 30°

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0.01000

0.01500

0.02000

0.02500

0.03000

0.03500

0.04000

0.04500

0.05000

0.05500

0.06000

0.06500

0.07000

0.07500

0.08000(Pst)

4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00


0.01000

0.01500

0.02000

0.02500

0.03000

0.03500

0.04000

0.04500

0.05000

0.05500

0.06000

0.06500

0.07000

0.07500

0.08000

0.08500

0.09000(Pst)

4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00


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0.01000

0.01500

0.02000

0.02500

0.03000

0.03500

0.04000

0.04500

0.05000

0.05500

0.06000

0.06500

0.07000

0.07500

0.08000

0.08500

0.09000

0.09500

0.10000(Pst)

4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00


For each network impedance phase angle ψk, the weighting procedure then calculates the weighted accumulated distribution functions of the flicker coefficients, Pr(c<x), assuming four different wind speed distributions. Pr(c<x) represents the distribution of flicker coefficients that would have been obtained if the measurements had been performed on a site with Rayleigh distributed wind speed of mean va. The weighted accumulated distribution of the flicker coefficient values is given by:

im

N

ii

xcim

N

ii

r

Nw

NwxcP

bin

bin

,1

,,1)(

∑

∑

=

<=

⋅

⋅=<

The 99 % percentile of the non normalised Pst value were calculated for the four grid impedance angles (30°, 50°, 70°, 85°) and the weighted accumulated distribution [Pr(c<x)]. The results from this are given in table 4.2.2.

Grid impedance angle (ψk)

30° 50° 70° 85°

Pst(ψk, va), va= 6.0 m/s 0.07 0.07 0.08 0.09

Pst(ψk, va), va= 7.5 m/s 0.07 0.07 0.08 0.09

Pst(ψk, va), va= 8.5 m/s 0.07 0.07 0.08 0.09

Pst(ψk, va), va= 10.0 m/s 0.07 0.08 0.09 0.09

Table 4.2.2: Pst-values for the selected grid impedance angles Each Pst value was then normalised to a flicker coefficient c(ψk,va), which is in principle independent of the selected short-circuit apparent power Sk, fic, and is given by the following:

of 100


n

fickakstak SS

vPvc ,),(),( ⋅Ψ=Ψ .

The results of the flicker coefficient c(ψk,va) for the four impedance angles are given in table 4.2.3. Grid impedance angle

(ψk) 30° 50° 70° 85°

c(ψk,va), va= 6.0 m/s 1.32 1.45 1.63 1.74

c(ψk,va), va= 7.5 m/s 1.34 1.47 1.66 1.78

c(ψk,va), va= 8.5 m/s 1.35 1.48 1.67 1.80

c(ψk,va), va= 10.0 m/s 1.35 1.52 1.71 1.82

Table 4.2.3: c(ψk,va)-values for the selected grid impedance angles

of 100


4.3 Harmonics The V90-3MW is equipped with a frequency converter system. In accordance with IEC 61400-21 [1] a measurement of the harmonics was carried out as specified in table 4.3.1. The results of these measurements are shown on the following pages.

Measurement period system number of 3-phase

measurements

sampling rate

Harmonics /Filter 2007-05-13 to 2007-06-27

DEWE 800

WT 300117906

+ DEWE Rack 16

WT 300103405

144 20 kHz

Table 4.3.1: Specification of the harmonics measurement The following graph shows the course of the power during the harmonics measurement. The calculation of the harmonics was carried out based on the values of current.

0

11000

22000

33000

44000

55000

66000

77000

88000

99000

110000

15.5.07 22.5.07 29.5.07 5.6.07 12.6.07 19.6.07 26.6.07

Datum Figure 4.3.1: rms-values of active power against time

of 100


Table 4.3.2 shows the distribution of the measurements (Note: for each measurement there are results for each of the three phases)

Rated power

[%] 0 - 10 10 - 20 20 �

30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90 90 - 100

Number of

values 31 10 14 11 16 7 7 2 5 41

Table 4.3.2: Distribution of the measurements

0.000.050.100.150.200.250.300.350.400.450.500.550.600.650.700.750.800.850.900.951.00

%

0 5 10 15 20 25 30 35 40 45 50

Order Figure 4.3.2:Measured spectrum of current harmonics

of 100


Table 4.3.3 shows the maximum harmonics as well as the current THD.

Order Active power currents

[ in kW ] [ % of Ir ]

3 96702.5 0.1

5 42931.7 1

7 67476.5 0.3

9 99754.8 0

11 689.6 0.3

13 6422 0.5

15 99769.1 0

17 99448.4 0

19 59188.1 0

21 6422 0

23 99747.2 0

25 6422 0

27 3495.8 0

29 30888.7 0

31 1882.7 0

33 94072.1 0

35 94072.1 0

37 94072.1 0

39 94072.1 0

41 98410.8 0

43 99638 0

45 94072.1 0

47 94072.1 0

49 94072.1 0


[ in kW ] [ % of Ir ]

2 11481.1 0.3

4 8249.2 0

6 5734.1 0

8 97272.7 0

10 52438.4 0

12 1078.4 0

14 98829.6 0

16 59188.1 0

18 11481.1 0

20 99759.8 0

22 59188.1 0

24 2354.5 0

26 99638 0

28 99789.3 0

30 6589.1 0

32 91781 0

34 94072.1 0

36 94072.1 0

38 94072.1 0

40 94072.1 0

42 99578.1 0

44 99578.1 0

46 97003.5 0

48 99638 0

50 99638 0

Max THC 1.077

Active Power at max THC [kW] 42931.66

Table 4.3.3: Maximum harmonics and current THD * In table 4.3.3 the values below 0.1 % of the rated current are not reported as per the IEC 61400-21 [1].

of 100


5 Realisation of the measurements and analysis of the acquired data (0-6 m/s)



Number of measured

values

Sampling rate



(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

271

(3-phase) 4 kHz

Power peaks 2007-05-11 to 2008-08-07


(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

271

(3-phase) 4 kHz



The maximum power values relating to the different averaging periods were derived from 10-minute-data-sets. For this calculation, only data collected during the continuous operation of the wind turbine were taken into account. The resulting distribution can be found in table 5.1.2


1 0 m/s to 0.5 m/s 0

2 0.5 m/s to 1.5 m/s 2

3 1.5 m/s to 2.5 m/s 3

4 2.5 m/s to 3.5 m/s 1

5 3.5 m/s to 4.5 m/s 63

6 4.5 m/s to 5.5 m/s 131

7 5.5 m/s to 6.5 m/s 71

8 6.5 m/s to 7.5 m/s 0


of 100



0

5

10

15

20

25

30

35

40

45

50

55

60

65MW

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0



P600 [kW] 63662.9

p600 =P600/Pn 0.6


of 100



0

5

10

15

20

25

30

35

40

45

50

55

60

65MW

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0



P60 [kW] 64833.8

p60 =P60/Pn 0.6


of 100



0

5

10

15

20

25

30

35

40

45

50

55

60

65

70MW

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0



P0.2 [kW] 65298.0

p0.2 =P0.2/Pn 0.6


of 100





0..10 222 4659.7 5803.7

10..20 28 14595.8 5344.5

20..30 12 27483 3920.4

30..40 2 35610 2717.1

40..50 4 48654.4 -95.7

50..60 3 59685.9 -3072.1

60..70 0 0 0

70..80 0 0 0

80..90 0 0 0

90..100 0 0 0

100..110 0 0 0

Table 5.1.6: Reactive power for the different power classes

The following three graphs show the relationship between reactive and active power represented by 10-minute averages, 1-minute averages and 0.2-second averages respectively. The first graph, figure 5.1.4, was used to determine the rated reactive power at rated active power, i.e. at P/Pn=1 (see section 3.1.2 of this report �Rated data�).

-4.5-4.0-3.5-3.0-2.5-2.0-1.5-1.0-0.50.00.51.01.52.02.53.03.54.04.55.05.56.06.5

Mvar

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60


of 100


-5.0-4.5-4.0-3.5-3.0-2.5-2.0-1.5-1.0-0.50.00.51.01.52.02.53.03.54.04.55.05.56.06.5

Mvar

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60


-5.0-4.5-4.0-3.5-3.0-2.5-2.0-1.5-1.0-0.50.00.51.01.52.02.53.03.54.04.55.05.56.06.5

Mvar

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60


The values for �Reactive power at Pmc�, �Reactive power at P60� and �Reactive power at P0.2� given in table 4.1.8 are derived from the data represented in the three previous graphs, i.e. figure 5.1.4, figure 5.1.5 and figure 5.1.6





of 100



Measurement Period System Averaging period

Number of measured

values

Sampling rate

Flicker 2007-05-11 to 2008-08-07


271

(3 phase) 2 kHz


• Un = 150 kV

• Sk,fic = 20 * Sn = 20 * 36 * 3 MVA = 2,16 GVA

• ψk = 30°, 50°, 70°, 85°

Using network modelling, the measured line current and the measured star voltage, a flicker burdened voltage was calculated for each line and for the four above mentioned angles ψk. These voltages comprise the input of the flicker algorithm according to IEC 61000-4-15 [2]. The result is a short term flicker value Pst. Using the above mentioned method Pst-values were determined for a power range which corresponds to a wind speed range from 0 m/s up to 6 m/s. The following four figures show the Pst values for the individual grid impedance angles against wind speed.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3(Pst)

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0


of 100


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3(Pst)

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45(Pst)

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0


of 100


0.00.20.40.60.81.01.21.41.61.82.02.22.42.62.83.03.23.43.63.84.04.2

(Pst)

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0



im

N

ii

xcim

N

ii

r

Nw

NwxcP

bin

bin

,1

,,1)(

∑

∑

=

<=

⋅

⋅=<



30° 50° 70° 85°

Pst(ψk, va), va= 6.0 m/s 1.2 1.21 0.18 0.49

Pst(ψk, va), va= 7.5 m/s 1.2 1.21 0.18 0.49

Pst(ψk, va), va= 8.5 m/s 0.84 0.84 0.18 0.49

Pst(ψk, va), va= 10.0 m/s 0.84 0.84 0.18 0.49

Table 5.2.2: Pst-values for the selected grid impedance angles

of 100


Each Pst value was then normalised to a flicker coefficient c(ψk,va), which is in principle independent of the selected short-circuit apparent power Sk, fic, and is given by the following:

n

fickakstak SS

vPvc ,),(),( ⋅Ψ=Ψ .


(ψk) 30° 50° 70° 85°

c(ψk,va), va= 6.0 m/s 24 24.19 3.56 9.72

c(ψk,va), va= 7.5 m/s 24 24.19 3.56 9.72

c(ψk,va), va= 8.5 m/s 16.71 16.83 3.56 9.72

c(ψk,va), va= 10.0 m/s 16.71 16.83 3.56 9.72


of 100




measurements

sampling rate


DEWE 800

WT 300117906

+ DEWE Rack 16

WT 300103405

257 20 kHz


0

5000

10000

15000

20000

25000

30000

35000

40000

45000

50000

55000

60000

65000kW

15.5.07 21.5.07 27.5.07 2.6.07 8.6.07 14.6.07 20.6.07 26.6.07

Date Figure 5.3.1: rms-values of active power against time

of 100



Rated power

[%] 0 - 10 10 - 20 20 �

30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90 90 - 100

Number of

values 211 27 11 2 3 3 0 0 0 0


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1%

1 8 15 22 29 36 43 50

Order Figure 5.3.2: Measured spectrum of current harmonics

of 100




[ in kW ] [ % of Ir ]

2 12139.1 0.3

4 4161.8 0

6 10787 0

8 9351.5 0

10 9351.5 0

12 2671.4 0

14 3821.4 0

16 5666.8 0

18 4160.2 0

20 13103.6 0

22 2671.4 0

24 4841.6 0

26 3652.5 0

28 2618.7 0

30 1567.6 0

32 2542.2 0

34 27368.7 0

36 27368.7 0

38 27368.7 0

40 27368.7 0

42 27883.8 0

44 27368.7 0

46 18664.7 0

48 8778.8 0

50 63671.6 0


[ in kW ] [ % of Ir ]

3 63671.6 0.1

5 4314.1 1

7 518.1 0.6

9 2618.7 0

11 2618.7 0.6

13 3803.8 0.6

15 5666.8 0

17 3302.4 0

19 1316.7 0

21 5666.8 0

23 2542.2 0

25 2542.2 0

27 5666.8 0

29 25890.6 0

31 6943.5 0

33 27368.7 0

35 27368.7 0

37 27368.7 0

39 27368.7 0

41 2618.7 0

43 3302.4 0

45 410.2 0

47 507.6 0

49 518.1 0

Max THC 1.101



of 100





Number of measured

values

Sampling rate



(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

490

(3-phase) 2 / 4kHz

Power peaks 2007-05-11 to 2008-08-07


(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

490

(3-phase) 2 / 4 kHz




Pmc [kW] 108000

pmc =Pmc/Pn 1.00


of 100



The maximum power values relating to the different averaging periods were derived from 10-minute-data-sets. For this calculation, only data collected during the continuous operation of the wind turbine were taken into account. The resulting distribution can be found in table 6.3.


1 0 m/s to 0.5 m/s 0

2 0.5 m/s to 1.5 m/s 0

3 1.5 m/s to 2.5 m/s 0

4 2.5 m/s to 3.5 m/s 0

5 3.5 m/s to 4.5 m/s 0

6 4.5 m/s to 5.5 m/s 0

7 5.5 m/s to 6.5 m/s 51

8 6.5 m/s to 7.5 m/s 132

9 7.5 m/s to 8.5 m/s 131

10 8.5 m/s to 9.5 m/s 92

11 9.5 m/s to 10.5 m/s 60

12 10.5 m/s to 11.5 m/s 24

13 11.5 m/s to 12.5 m/s 0

Table 6.3: Number of 10-minute-average data sets

of 100



5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85MW

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0



P600 [kW] 82207.8

p600 =P600/Pn 0.76


of 100



5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90MW

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0



P60 [kW] 85728.7

p60 =P60/Pn 0.79


of 100



5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90MW

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0



P0.2 [kW] 87380.0

p0.2 =P0.2/Pn 0.81


of 100





0..10 26 9162.1 5653.4

10..20 97 16145.6 5172.1

20..30 126 26709.4 4009.1

30..40 79 37716 2169.8

40..50 96 48663.5 -150.7

50..60 52 58151.4 -2743.3

60..70 11 68824.3 -6217.9

70..80 3 79739.7 -10532.4

80..90 0 0 0

90..100 0 0 0

100..110 0 0 0

Table 6.1.7Reactive power for the different power classes


-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6Mvar

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8


of 100


-14

-13

-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6Mvar

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8


-14

-13

-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6Mvar

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8


of 100







of 100




Number of measured

values

Sampling rate

Flicker 2007-05-11 to 2008-08-07


490

(3 phase) 2 kHz


• Un = 150 kV

• Sk,fic = 20 * Sn = 20 * 36 * 3 MVA = 2,16 GVA

• ψk = 30°, 50°, 70°, 85°


0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

0.065(Pst)

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0


of 100


0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

0.065

0.070(Pst)

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0


0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

0.065

0.070

0.075

0.080(Pst)

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0


of 100


0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

0.065

0.070

0.075

0.080

0.085(Pst)

6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0



im

N

ii

xcim

N

ii

r

Nw

NwxcP

bin

bin

,1

,,1)(

∑

∑

=

<=

⋅

⋅=<



30° 50° 70° 85°

Pst(ψk, va), va= 6.0 m/s 0.05 0.06 0.06 0.06

Pst(ψk, va), va= 7.5 m/s 0.06 0.06 0.06 0.07

Pst(ψk, va), va= 8.5 m/s 0.06 0.06 0.06 0.07

Pst(ψk, va), va= 10.0 m/s 0.06 0.06 0.06 0.07


of 100



n

fickakstak SS

vPvc ,),(),( ⋅Ψ=Ψ .


(ψk) 30° 50° 70° 85°

c(ψk,va), va= 6.0 m/s 1.1 1.16 1.27 1.35

c(ψk,va), va= 7.5 m/s 1.12 1.19 1.32 1.41

c(ψk,va), va= 8.5 m/s 1.13 1.21 1.33 1.42

c(ψk,va), va= 10.0 m/s 1.15 1.24 1.36 1.45


of 100


6.3 Harmonics The V90-3MW is equipped with a frequency converter system. A measurement of the harmonics was carried out as specified in table 6.4.1 The results of these measurements are shown on the following pages.


measurements

sampling rate


DEWE 800

WT 300117906

+ DEWE Rack 16

WT 300103405

451 20 kHz


0

5000

10000

15000

20000

25000

30000

35000

40000

45000

50000

55000

60000

65000

70000

75000

80000

kW

7 15.5.07 22.5.07 29.5.07 5.6.07 12.6.07 19.6.07 26.6.07 3.7.07

Date Figure 6.3.1: rms-values of active power against time

of 100



Rated power

[%] 0 - 10 10 - 20 20 �

30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90 90 - 100

Number of

values 24 81 112 74 96 51 10 3 0 0


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2%

0 5 10 15 20 25 30 35 40 45 50

Order

Figure 6.3.2: Measured spectrum of current harmonics

of 100




[ in kW ] [ % of Ir ]

2 10474.2 0.3

4 11623 0

6 9458.6 0

8 73386.5 0

10 47409.5 0

12 12009.6 0

14 82146.9 0

16 73498 0

18 11481.1 0

20 11481.1 0

22 52198.7 0

24 9354.3 0

26 39525.7 0

28 64156.8 0

30 9354.3 0

32 46891.2 0

34 30342.8 0

36 30342.8 0

38 30342.8 0

40 30342.8 0

42 30342.8 0

44 78093.2 0

46 55073.1 0

48 39525.7 0

50 39525.7 0


[ in kW ] [ % of Ir ]

3 82146.9 0.1

5 64156.8 1.1

7 28316.7 0.3

9 82146.9 0

11 39779.4 0.2

13 25392.7 0.4

15 48968.5 0

17 28316.7 0

19 48018.4 0

21 34837.4 0

23 73498 0

25 73498 0

27 25392.7 0

29 47761.4 0

31 39081.4 0

33 39779.4 0

35 30342.8 0

37 30342.8 0

39 30342.8 0

41 30342.8 0

43 39081.4 0

45 42245.8 0

47 47978.3 0

49 30342.8 0

Max THC 1.209



of 100





Number of measured

values

Sampling rate



(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

83

(3-phase) 2 / 4kHz

Power peaks 2007-05-11 to 2008-08-07


(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

83

(3-phase) 2 / 4 kHz




Pmc [kW] 108000

pmc =Pmc/Pn 1.00


of 100





1 0 m/s to 0.5 m/s 0

2 0.5 m/s to 1.5 m/s 0

3 1.5 m/s to 2.5 m/s 0

4 2.5 m/s to 3.5 m/s 0

5 3.5 m/s to 4.5 m/s 0

6 4.5 m/s to 5.5 m/s 0

7 5.5 m/s to 6.5 m/s 0

8 6.5 m/s to 7.5 m/s 0

9 7.5 m/s to 8.5 m/s 0

10 8.5 m/s to 9.5 m/s 0

11 9.5 m/s to 10.5 m/s 0

12 10.5 m/s to 11.5 m/s 15

13 11.5 m/s to 12.5 m/s 20

14 12.5 m/s to 13.5 m/s 14

15 13.5 m/s to 14.5 m/s 11

16 14.5 m/s to 15.5 m/s 16

17 15.5 m/s to 16.5 m/s 7


of 100



50

55

60

65

70

75

80

85

90

95

100MW

11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0


The maximum of all of these 600-second-average active power values, P600, together with the ratio of this to the nominal output power of the turbine is given in table 7.1.4

P600 [kW] 99476.4

p600 =P600/Pn 0.92


of 100



56586062646668707274767880828486889092949698

100MW

11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0



P60 [kW] 99841.8

p60 =P60/Pn 0.92


of 100



586062646668707274767880828486889092949698

100102

MW

11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0



P0.2 [kW] 100360.8

p0.2 =P0.2/Pn 0.93


of 100





0..10 0 0 0

10..20 0 0 0

20..30 0 0 0

30..40 0 0 0

40..50 2 53457.4 -1951.2

50..60 8 58687.1 -3037.0

60..70 21 68988.9 -6445.2

70..80 18 79553.6 -10468.0

80..90 25 92286.9 -16041.2

90..100 9 98654.3 -18394.0

100..110 0 0 0



-20

-19

-18

-17

-16

-15

-14

-13

-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1Mvar

0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95


of 100


-20

-19

-18

-17

-16

-15

-14

-13

-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2Mvar

0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95


-20

-19

-18

-17

-16

-15

-14

-13

-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2Mvar

0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95







of 100




Number of measured

values

Sampling rate

Flicker 2007-05-11 to 2008-08-07


83

(3 phase) 2 kHz


• Un = 150 kV

• Sk,fic = 20 * Sn = 20 * 36 * 3 MVA = 2,16 GVA

• ψk = 30°, 50°, 70°, 85°


0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

0.065

0.070(Pst)

11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0


of 100


0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

0.065

0.070

0.075

0.080(Pst)

11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0


0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

0.065

0.070

0.075

0.080

0.085

0.090(Pst)

11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0


of 100


0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

0.050

0.055

0.060

0.065

0.070

0.075

0.080

0.085

0.090

0.095(Pst)

11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0



im

N

ii

xcim

N

ii

r

Nw

NwxcP

bin

bin

,1

,,1)(

∑

∑

=

<=

⋅

⋅=<

The 99 % percentile of the non normalised Pst value were calculated for the four grid impedance angles (30°, 50°, 70°, 85°) and the weighted accumulated distribution [Pr(c<x)]. The results from this are given in table 7.2.2


30° 50° 70° 85°

Pst(ψk, va), va= 6.0 m/s 0.07 0.07 0.08 0.09

Pst(ψk, va), va= 7.5 m/s 0.07 0.08 0.09 0.09

Pst(ψk, va), va= 8.5 m/s 0.07 0.08 0.09 0.09

Pst(ψk, va), va= 10.0 m/s 0.07 0.08 0.09 0.09


of 100



n

fickakstak SS

vPvc ,),(),( ⋅Ψ=Ψ .


(ψk) 30° 50° 70° 85°

c(ψk,va), va= 6.0 m/s 1.33 1.49 1.68 1.80

c(ψk,va), va= 7.5 m/s 1.37 1.53 1.72 1.84

c(ψk,va), va= 8.5 m/s 1.37 1.53 1.72 1.84

c(ψk,va), va= 10.0 m/s 1.37 1.53 1.72 1.84


of 100



Measurement Period System number of 3-phase

measurements

sampling rate


DEWE 800

WT 300117906

+ DEWE Rack 16

WT 300103405

82 20 kHz


0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000kW

7 15.5.07 22.5.07 29.5.07 5.6.07 12.6.07 19.6.07 26.6.07 3.7.07

Date Figure 7.3.1: Normalised rms-values of active power against time

of 100



Rated power

[%] 0 - 10 10 - 20 20 �

30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90 90 - 100

Number of

values 0 0 0 0 2 8 19 19 25 9


0.000.050.100.150.200.250.300.350.400.450.500.550.600.650.700.750.800.850.900.951.00

%

0 5 10 15 20 25 30 35 40 45 50


of 100




[ in kW ] [ % of Ir ]

2 57346.3 0.3

4 91120.3 0

6 91120.3 0

8 80466.3 0

10 77249.1 0

12 97272.7 0

14 90736.4 0

16 59188.1 0

18 65269.6 0

20 94576.3 0

22 87663.9 0

24 54282.8 0

26 91128.5 0

28 88819.7 0

30 79456.9 0

32 79456.9 0

34 94072.1 0

36 77454.7 0

38 94072.1 0

40 94072.1 0

42 99297.5 0

44 91128.5 0

46 91128.5 0

48 91128.5 0

50 91128.5 0


[ in kW ] [ % of Ir ]

3 89121.5 0.1

5 76388.9 1

7 67476.5 0.3

9 97948.2 0

11 79456.9 0.2

13 99246.5 0.3

15 99246.5 0.1

17 99464.9 0

19 76388.9 0

21 76363.8 0

23 77454.7 0

25 87663.9 0

27 76363.8 0

29 80498.8 0

31 80498.8 0

33 94072.1 0

35 94072.1 0

37 94072.1 0

39 94072.1 0

41 98410.8 0

43 57346.3 0

45 94072.1 0

47 94072.1 0

49 94072.1 0

Max THC 1.081



of 100





Number of measured

values

Sampling rate



(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

33

(3-phase) 2 / 4kHz

Power peaks 2007-05-11 to 2008-08-07


(WT300118006) (WT300102505)

0.2 s

1 minute

10 minute

33

(3-phase) 2 / 4 kHz



The maximum permitted power was provided by the manufacturer and is given in table 8.1.2. together with the ratio of this to the nominal output power of the turbine.

Pmc [kW] 108000

pmc =Pmc/Pn 1.00


of 100





1 0 m/s to 0.5 m/s 0

2 0.5 m/s to 1.5 m/s 0

3 1.5 m/s to 2.5 m/s 0

4 2.5 m/s to 3.5 m/s 0

5 3.5 m/s to 4.5 m/s 0

6 4.5 m/s to 5.5 m/s 0

7 5.5 m/s to 6.5 m/s 0

8 6.5 m/s to 7.5 m/s 0

9 7.5 m/s to 8.5 m/s 0

10 8.5 m/s to 9.5 m/s 0

11 9.5 m/s to 10.5 m/s 0

12 10.5 m/s to 11.5 m/s 0

13 11.5 m/s to 12.5 m/s 0

14 12.5 m/s to 13.5 m/s 0

15 13.5 m/s to 14.5 m/s 0

16 14.5 m/s to 15.5 m/s 0

17 15.5 m/s to 16.5 m/s 6

18 16.5 m/s to 17.5 m/s 12

19 17.5 m/s to 18.5 m/s 8

20 18.5 m/s to 19.5 m/s 3

21 19. 5 m/s to 20.5 m/s 4

22 20.5 to 21.5 m/s 0


of 100



84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100MW

16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0



P600 [kW] 99803.13

p600 =P600/Pn 0.92


of 100



88.589.089.590.090.591.091.592.092.593.093.594.094.595.095.596.096.597.097.598.098.599.099.5

100.0MW

16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0



P60 [kW] 99821.1

p60 =P60/Pn 0.92


of 100



89

90

91

92

93

94

95

96

97

98

99

100

101MW

16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0



P0.2 [kW] 100627.5

p0.2 =P0.2/Pn 0.93


of 100



For the calculation of the reactive power, only data acquired during the continuous operation of the wind turbine were utilised. The 10-minute-average data were classified using the method of bins. The data used in the calculation are summarised in the previous table 4.1.3. The results are listed in table 8.1.7. below.


0..10 0 0 0

10..20 0 0 0

20..30 0 0 0

30..40 0 0 0

40..50 0 0 -0

50..60 0 0 0

60..70 0 0 0

70..80 1 84515.6 -13372.7

80..90 12 94450.7 -16950.6

90..100 20 99560.8 -19102.9

100..110 0 0 0



-20.0

-19.5

-19.0

-18.5

-18.0

-17.5

-17.0

-16.5

-16.0

-15.5

-15.0

-14.5

-14.0

-13.5

-13.0Mvar

0.750 0.775 0.800 0.825 0.850 0.875 0.900 0.925 0.950


of 100


-20.0

-19.5

-19.0

-18.5

-18.0

-17.5

-17.0

-16.5

-16.0

-15.5

-15.0

-14.5Mvar

0.750 0.775 0.800 0.825 0.850 0.875 0.900 0.925 0.950


-20.0

-19.5

-19.0

-18.5

-18.0

-17.5

-17.0

-16.5

-16.0

-15.5

-15.0Mvar

0.750 0.775 0.800 0.825 0.850 0.875 0.900 0.925 0.950


The values for �Reactive power at Pmc�, �Reactive power at P60� and �Reactive power at P0.2� given figure 8.1.7 are derived from the data represented in the three previous graphs, i.e figure 8.1.4, figure 8.1.5 and figure 8.1.6.





of 100


8.2 Voltage fluctuations The specifications given figure 8.2.1 are valid for the following subsections. Only data associated with the continuous operation of the wind turbine were taken into account for the evaluation of flicker.


Number of measured

values

Sampling rate

Flicker 2007-05-11 to 2008-08-07


33

(3 phase) 2 kHz


• Un = 150 kV

• Sk,fic = 20 * Sn = 20 * 36 * 3 MVA = 2,16 GVA

• ψk = 30°, 50°, 70°, 85°


0.0625

0.0630

0.0635

0.0640

0.0645

0.0650

0.0655

0.0660

0.0665

0.0670

0.0675(Pst)

16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0


of 100


0.0685

0.0690

0.0695

0.0700

0.0705

0.0710

0.0715

0.0720

0.0725

0.0730

0.0735

0.0740

0.0745

0.0750

0.0755

0.0760

0.0765

0.0770(Pst)

16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0


0.0770

0.0775

0.0780

0.0785

0.0790

0.0795

0.0800

0.0805

0.0810

0.0815

0.0820

0.0825

0.0830

0.0835

0.0840

0.0845

0.0850

0.0855

0.0860

0.0865

0.0870(Pst)

16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0


of 100


0.08250.08300.08350.08400.08450.08500.08550.08600.08650.08700.08750.08800.08850.08900.08950.09000.09050.09100.09150.09200.09250.0930

(Pst)

16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0



im

N

ii

xcim

N

ii

r

Nw

NwxcP

bin

bin

,1

,,1)(

∑

∑

=

<=

⋅

⋅=<



30° 50° 70° 85°

Pst(ψk, va), va= 6.0 m/s 0.07 0.08 0.09 0.09

Pst(ψk, va), va= 7.5 m/s 0.07 0.08 0.09 0.09

Pst(ψk, va), va= 8.5 m/s 0.07 0.08 0.09 0.09

Pst(ψk, va), va= 10.0 m/s 0.07 0.08 0.09 0.09


of 100



n

fickakstak SS

vPvc ,),(),( ⋅Ψ=Ψ .


(ψk) 30° 50° 70° 85°

c(ψk,va), va= 6.0 m/s 1.33 1.51 1.70 1.81

c(ψk,va), va= 7.5 m/s 1.33 1.51 1.70 1.81

c(ψk,va), va= 8.5 m/s 1.33 1.51 1.70 1.81

c(ψk,va), va= 10.0 m/s 1.33 1.51 1.70 1.81


of 100




measurements

sampling rate


DEWE 800

WT 300117906

+ DEWE Rack 16

WT 300103405

33 20 kHz


0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000kW

15.5.07 22.5.07 29.5.07 5.6.07 12.6.07 19.6.07 26.6.07 3.7.07

Date Figure 8.3.1: Normalised rms-values of active power against time

of 100



Rated power

[%] 0 - 10 10 - 20 20 �

30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90 90 - 100

Number of

values 0 0 0 0 0 0 0 1 12 20


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90%

0 5 10 15 20 25 30 35 40 45 50


of 100




[ in kW ] [ % of Ir ]

2 99759.8 0.3

4 92967.9 0

6 92967.9 0

8 94432.2 0

10 84224.5 0

12 94432.2 0

14 93857.1 0

16 99796.7 0

18 94139 0

20 99637.3 0

22 94432.2 0

24 94139 0

26 99638 0

28 99789.3 0

30 94352.8 0

32 99759.3 0

34 99637.3 0

36 94139 0

38 99282.1 0

40 92967.9 0

42 99578.1 0

44 99578.1 0

46 97003.5 0

48 99638 0

50 99638 0


[ in kW ] [ % of Ir ]

3 84224.5 0.1

5 84224.5 0.9

7 84224.5 0.3

9 92967.9 0

11 99754.8 0.2

13 93857.1 0.3

15 93857.1 0

17 99448.4 0

19 94352.8 0

21 99769.1 0

23 94352.8 0

25 94352.8 0

27 94139 0

29 99754.8 0

31 93857.1 0

33 99769.1 0

35 99769.1 0

37 99744.4 0

39 94139 0

41 99638 0

43 99638 0

45 97003.5 0

47 92967.9 0

49 84224.5 0

Max THC 0.962



of 100


W T

G r id

d a t a a q u is i t i o ns y s t e m

I 1

I 2

I 3

U 1

U 2

U 3

c u r r e n t p r o b e s

L 1 L 2 L 3

a n e m o m e t e r

W S

9 Uncertainty analysis

9.1 Estimation of the uncertainties in the power quality measurement The uncertainties were calculated in accordance with QMP09 [3]. The used measurement system has several components which lead to measurement errors. The measurement system applied comprises the following components:

• Current probes

• Isolating amplifiers

• Antialiasing filters

• A/D-converter

• Software

Figure 9.1.1 shows a schematic diagram of the measurement equipment.

Figure 9.1.1: Measurement equipment

of 100


Table 9.1.1 and table 9.1.2 show the estimated uncertainties for the different parts of the measurement system. According to the guide to the expression of uncertainty in measurement (GUM) [4] it is recommended to divide the uncertainties into categories. The uncertainties for the amplitude were calculated using the measurement range. The uncertainties for frequency and phasing were calculated using the measured value.

Part of measurement

system Source of error

Category of uncertainty according to the GUM guideline

Sensitivity factor Distribution Type of error

Estimated uncertainty

(range)

Amplitude B 1 Rectangle Amplitude 0.30 %*Phase shift B 1 Rectangle Phasing 0.30 °

Temperature B 1 Rectangle Amplitude 0.05 %Relative Humidity B 1 Rectangle Amplitude 0.05 %

Current transformers

Arrangement B 1 Rectangle Amplitude 0.10 %Amplitude B 1 Rectangle Amplitude 0.30 %*Phase shift B 1 Rectangle Phasing 0.30 °

Temperature B 1 Rectangle Amplitude 0.05 %Relative Humidity B 1 Rectangle Amplitude 0.05 %

Voltage transfomers

Arrangement B 1 Rectangle Amplitude 0.10 %EMC B 1 Rectangle Amplitude 0.01 %

Impedance of wire B 1 Rectangle Amplitude 0.00 %

Measurement wiring

EMC B 1 Rectangle Frequency 0.00 %

Amplitude (current signal) B 1 Rectangle Amplitude 0.05 %

Frequency attenuation B 1 Rectangle Frequency Below 20 kHz

→ 0.00%Phase shift B 1 Rectangle Phasing 0 °

Temperature B 1 Rectangle Amplitude 0.01 %

Isolation amplifiers

Amplitude (voltage signal) B 1 Rectangle Amplitude 0.10 %

Quantisation (24 bit

resolution) B 1 Rectangle Amplitude 0.00012 %

Phase shift B 1 Rectangle Phasing 0 °Frequency B 1 Rectangle Frequency 0.0025 %Amplitude B 1 Rectangle Amplitude 0.05 %Offset drift B 1 Rectangle Amplitude 0.0005 %

A/D-converter

Temperature B 1 Rectangle Amplitude 0.003 %Table 9.1.1: Estimation of uncertainties in the measurement system � Hardware

* derived from the calibration certificates in appendix 12.4

of 100


Part of measurement

system Source of error

Category of uncertainty according to the GUM guideline

Sensitivity factor Distribution Type of

error

Estimated uncertainty

(range)

Sampling rate B 1 Rectangle Amplitude 0.10 %Calculation B 1 Rectangle Power 0.00 %Phase shift B 1 Rectangle Power 0.01 %

Power Software

Distortion power B 1 Rectangle Power 0.01 %Sampling rate B 1 Rectangle Amplitude 0.50 %

Calculation B 1 Rectangle Flicker 0.00 %Flicker

Software Flicker model B 1 Rectangle Flicker 5.00 %

Sampling rate B 1 Rectangle Amplitude 0.03 %

Calculation of kf B 1 Rectangle Switching Flicker 5.00 %

Switching Operations Software

Calculation of ku B 1 Rectangle Switching voltage 0.10 %

Sampling rate B 1 Rectangle Amplitude/ Frequency

0.001 to0.3 %

(50 Hz to2500 Hz)Harmonics

Software

Frequency response B 1 Rectangle Frequency

0.000034 to0.81 %

(50 Hz to2500 Hz)

Table 9.1.2: Estimation of uncertainties in the measurement system � Software The total estimated uncertainties associated with the results of the power quality measurement are given in table 9.1.3. In this context, the level of confidence is a probability range, within which these uncertainties have to be arranged.

Total estimated uncertainty type U [%] of range level of confidence

Evaluation of apparent power 0.37 95%

Evaluation of active power 0.95 95%

Evaluation of reactive power 0.95 95%

Evaluation of flicker values (Pst) 4.81 95%

Evaluation of kf-factor (switching operations) 4.77 95%

Evaluation of ku-factor (switching operations) 0.34 95%

Table 9.1.3: Total estimated uncertainties for each type of measurement

of 100


Table 9.1.4 shows the estimated uncertainties in the result values of harmonics. The uncertainties for the amplitude were calculated using the measurement range.

Frequency [Hz]

Accuracy of amplitude due

to current probe [% of

range]

Uncertainty due to the

current probes [% of

range]

Uncertainty due to the

sampling rate [% of range]

Standard deviation of amplitude

[% of range]

Standard deviation of amplitude

[% of range with 95 % level of confidence]

50 0.33 0.0 0.00 0.33 0.31

1000 0.33 0.0 0.04 0.33 0.31

2000 0.33 0.1 0.08 0.35 0.33

7000 0.33 0.5 0.51 0.78 0.74

9000 0.33 1.0 0.50 1.16 1.11

Table 9.1.4: Estimated uncertainties in the harmonics result values

influence of frequency on current measurement

0,00

0,20

0,40

0,60

0,80

1,00

1,20

0 2000 4000 6000 8000 10000

Frequency [Hz]

Am

plitu

de s

tand

ard

unce

rtain

ty [

% o

f the

end

of

mea

sure

men

t ran

ge]

with

con

fiden

ce le

vel o

f 95%

Figure 9.1.2: Amplitude standard uncertainty

of 100


9.2 Errors due to current transformers The employed current probes were calibrated. The respective uncertainty values are shown in table 9.1.1.

9.3 Errors due to voltage transformers The employed voltage probes were calibrated. The respective uncertainty values are shown in table 9.1.1.

9.4 Errors due to the measurement wiring Errors due to the measurement wiring are caused by electromagnetic fields and losses due to the impedance of the wiring. In the case of the current measurement the current clamps provide an active current signal, so that no losses due to impedance were considered. In the case of the voltage measurement, however, the losses due to impedance need to be considered. The error in the voltage measurement could be determined by the impedance of the wire in proportion to the impedance of the isolating amplifier. No significant influences of electromagnetic fields on the measurement system are known. A proper installation of measurement wiring has been carried out in order to avoid inductive couplings.

9.5 Errors due to the isolating amplifier Two different amplifiers were used for the current and the voltage channels. The isolating amplifier for the current is a DEWE-DAQP-V which has an error of 0.05 % from the maximum input level. The isolating amplifier for the voltage is a DEWE-DAQP-DMM � type, which has an error of 0.1 % of the maximum input level.

9.6 Errors due to the A/D � converter The used DEWE 800 + DEWE Rack 16 systems were equipped with a 24 bit A/D � converter module.

9.7 Errors due to the sampling rate and software Shannon�s theorem states that a minimum sampling rate of twice the maximum measured frequency is needed, in order to avoid aliasing effects.

9.7.1 Power measurement

For the determination of the power values, the amplitude- and phase-measurement of currents and voltages at the rated grid frequency have to be performed very accurately.

9.7.2 Flicker measurement

Flicker is based on amplitude modulation on the fundamental frequency. For the flicker effect, only frequencies in the range of 0.1 Hz up to 35 Hz are relevant. Therefore, the flicker measurement only has to allow for a frequency range of 0.1 Hz up to 85 Hz.

9.7.3 Sampling rate

The following equation provides an estimation of the error caused by the sampling rate:

2

22

6 A

SG

FF

E⋅⋅

≈π .

E : Uncertainties in % of the measurement range

FSG : Measured frequency

FA : Sampling rate

of 100


10 Summary The V90 - 3 MW is fitted with an active power regulation system, a double fed asynchronous generator and a frequency converter. The electrical properties of the measured wind turbines are reflected in the measurement results. The measurement in the onshore substation Wijk aan Zee of the offshore wind farm Egmond aan Zee was carried out on a 50 Hz grid at a voltage level of 150 kV. The measurements on the wind farm are related to the IEC61400-21, which is only valid for single wind turbines. The analysis has been carried out for four ranges of wind speed and for a stable count of 35 connected wind turbines. This subdivision of the recorded datasets was done, because the wind park shows a different behaviour in the several ranges of wind speed. The stable count of connected turbines was analysed to exclude the effect of switching turbines.

10.1 35 connected turbines Active power values: Pmc, maximum permitted power 105000 kW

P60, maximum power for 60 s average period 99580.4 kW

P0.2, maximum power for 0.2 s average period 100271.1 kW Reactive power: Reactive Power at Pmc -19908.8 kvar

Reactive Power at P60 -19026.7 kvar

Reactive Power at P0.2 -19615.4 kvar Flicker:


30° 50° 70° 85°

c(ψk), va= 6.0 m/s 1.32 1.45 1.63 1.74

c(ψk), va= 7.5 m/s 1.34 1.47 1.66 1.78

c(ψk), va= 8.5 m/s 1.35 1.48 1.67 1.80

c(ψk), va= 10.0 m/s 1.35 1.52 1.71 1.82 Maximum THD: 1.132 % of the rated current at an active power of 4.314 MW. The results given in this report are only valid for these measured wind turbines and test site.

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10.2 All measurement data with a mean wind speed range from 0 m/s to 6 m/s Active power values: Pmc, maximum permitted power 108000 kW






30° 50° 70° 85°

c(ψk), va= 6.0 m/s 24 24.19 3.56 9.72

c(ψk), va= 7.5 m/s 24 24.19 3.56 9.72

c(ψk), va= 8.5 m/s 16.71 16.83 3.56 9.72


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10.3 All measurement data with a mean wind speed range from 6 m/s to 11 m/s Active power values: Pmc, maximum permitted power 108000 kW






30° 50° 70° 85°

c(ψk), va= 6.0 m/s 1.10 1.16 1.27 1.35

c(ψk), va= 7.5 m/s 1.12 1.19 1.32 1.41

c(ψk), va= 8.5 m/s 1.13 1.21 1.33 1.42


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10.4 All measurement data with a mean wind speed range from 11 m/s to 16 m/s

Active power values: Pmc, maximum permitted power 108000 kW






30° 50° 70° 85°

c(ψk), va= 6.0 m/s 1.33 1.49 1.68 1.80

c(ψk), va= 7.5 m/s 1.37 1.53 1.72 1.84

c(ψk), va= 8.5 m/s 1.37 1.53 1.72 1.84


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10.5 All measurement data with a mean wind speed range from 16 m/s to 20 m/s

Active power values: Pmc, maximum permitted power 108000 kW






30° 50° 70° 85°

c(ψk), va= 6.0 m/s 1.33 1.51 1.70 1.81

c(ψk), va= 7.5 m/s 1.33 1.51 1.70 1.81

c(ψk), va= 8.5 m/s 1.33 1.51 1.70 1.81


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11 References [1] IEC 61400-21:2001, Measurement and assessment of power quality characteristics of grid

connected wind turbines, First edition, 2001-12

[2] IEC 61000-4-15:1997+A1:2003, Electromagnetic compatibility (EMC) � Part 4: Testing and measurement techniques � Section 15: Flickermeter � Functional and design specifications, Edition 1.1, 2003-02

[3] Quality management guide of WINDTEST Kaiser-Wilhelm-Koog GmbH: QMP 09, Measurement of electrical characteristics of wind turbines, Revision 11, 2006-08-24

[4] Guide to the expression of uncertainty in measurement (GUM): German version ENV 13005: 1999

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12 Appendix 12.1 Manufacture�s certificate ...................................................................................................... 95 12.2 Calibration certificate of the DEWE800 ............................................................................... 96 12.3 Calibration certificate of the DEWE-RACK 16 ..................................................................... 97 12.4 Calibration certificates of the current transformers.............................................................. 98

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12.1 Manufacture�s certificate There was no certificate provided by the customer.

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12.2 Calibration certificate of the DEWE800

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12.3 Calibration certificate of the DEWE-RACK 16

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12.4 Calibration certificates of the current transformers

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WINDTEST - NoordzeeWind€¦ · · 2015-07-01Vestas Offshore The Netherlands B.V ... under test...

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