Nr. 1 POWER PRODUCT LINE DEWETRON - Power Product Line PQ System installation and evaluation of Wind Power Plants in Europe Seoul 2009 09 Dr. Werner Schoeffer.

Nr. 1 POWER PRODUCT LINE

DEWETRON - Power Product Line

PQ System installation and evaluation of Wind Power Plants in

Europe

Seoul 2009 09

Dr. Werner Schoeffer

DEWETRON GmbH

Parkring 4, A-8074 Grambach

E-mail: [email protected], Phone: +43 316 3070 125


Quality characteristics of Power

1. 230 V (220 V, 110V or different)

2. AC - sinewave

3. 50 (60) Hz

5. Availability

4. 3 phases


Reasons for PQM

• Electrical energy is an open

market and the quality of the

product has to be defined

• TQM (total quality monitoring) must also be done for this product.

• The user has the right to get a product which fits to the standard (EN50160)

• The supplier has to guarantee the quality.• In judicial proceedings the prosecutor has to present the

facts.


Situation Today

• Energy has been monitored since electrical energy has been distributed.

• The flow of active power and reactive power is known very well in most of the substations.

• Faults have been recorded by the use of paper recorders or in protection relays.

• Power quality has been measured in case of troubles.


Renewables are coming

• “Renewable Energy” are a lot of small power plants feeding into the grid.

• Sometimes they can control the voltage level.

• Voltage variations and Harmonics are coming up more and more because of electronic loads and decentralized power generation.


Standards and Regulations

• EN50160 Voltage levels in public power grids

• IEC 61000-4-7 harmonics measurement• IEC 61000-4-15 flicker measurement• IEC 61000-4-30 PQ measurement methods

• IEC 61400-21 Measurement and assessment of power quality characteristics of grid connected wind turbines


EN 50160EC-directive 85/374 – standardization of the EC-directive 85/374 – standardization of the product liabilty lawsproduct liabilty laws

Electricity became a productElectricity became a product

Quality characteristics for the product Quality characteristics for the product Electricity (voltage) have been usedElectricity (voltage) have been used

EN 50160EN 50160

Customers can be sure, that the quality of their voltage supply is in any point of the supply grid, under normal conditions, at least conform to the EN 50160


EN 50160 in details


EN 50160 (1)

10sec-avg value, 99,5% of a year: 50Hz, +/- 1% (stand alone: +/- 2%@95% of a week) 100 % of a year: +4%/-6% (stand alone : +/- 15%@100%)

frequency


EN 50160 (2)

phase voltage (line to earth, lower voltage grid)

230 V~

(attention: until 2006: 220 V)

transmission grid: 1 kV to 35 kV line to line voltage(must be defined)


EN 50160 (3)

MV+LV:95% of the 10min-avg values have to be in the range of +/-10% U

slow voltage variations

LV:100% of the 10min-avg values have to be in the range of +10/-15% U


EN 50160 (4)

Flicker:

PLT=1 in 95% of a week

fast voltage fluctuations and flicker

Voltage fluctuations:

Low voltage:<5% 10ms (up tp 10%)

Medium voltage:<4% 10ms (up to 6%)


EN 50160 (5)

dips: <60% , 10-1000 per year

Voltage dips


EN 50160 (6)

short: < 1sec, 10-100 per yearlong: < 3 min (30% of counted short)

interruptions


EN 50160 (7)

Very long interruptions: > 3 min, 10-50 per year

voltage drop out

Proclaimed (in case of service): always


EN 50160 (8)

net frequent over voltages:LV: <440V@5sec; < 1,5 kV short circuitMV: <1,7 – 2*Uc


EN 50160 (9)

TransientsLower voltage: <6kV


EN 50160 (10)

unsymmetry

%2pos

neg

U

U

in 95% of a week


EN 50160 (11)

Harmonics @95% of a week

THD < 8%

harmonics in detailH3: 5%H5: 6%H7: 5%H9: 1,5%H11: 3,5%H13: 5%H15: 0,5%H17: 2%H19: 1,5%H21: 0,5%H23: 1,5%H25: 1,5%

H2: 2%H4: 1%Others (up to 25): 0,5%


EN 50160 (12)

interharmonics

not defined

But: flicker


EN 50160 (13)

frequency depending limit curve

Telegram voltages


When and where is EN 50160 valid ?

• Connection point public grid – customer

• Low voltage (400V) and medium voltage (1kV to 35 kV) systems

• Under normal operation conditions

• Not after faults !

New: application guide !


IEC 61000-4-30 Classes

• Class A: This class is used where precise measurement is necessary, such as contractual applications that may require resolving disputes, verifying compliance with standards, etc. Any measurements of a parameter carried out by two different instruments complying with the requirements of class A, when measuring the same signals, will produce matching results within the specified uncertainty for that parameter.

• Class S: NEW “under construction”. This class is used for statistical applications such as surveys or power quality assessment, possibly with a limited subset of parameters. Although it uses equivalent intervals of measurement as used in class A, the class S processing requirements are much lower.

• Class B: This class may be used for quality surveys, trouble shooting applications and other applications when low uncertainty is not required.


Additional Standards

• Voltage levels in customers grids (e.g. IEC 61000-2-4)

• Emission levels of equipment (e.g. IEC 61000-3-x)• Regulations for the connection of customers to

public grids (e.g. TOR D2 in “D A CH CZ”)• Special standards for renewable energy (e.g.

61400-21 windmills)• Environment for IT

– ITIC, former CBEMA curve

• Voltage interruptions – Unipede statistics,– SAIFI, SAIDI, CAIDI, etc.)


Europe• All EC members have a regulatory body.

• They should get the PQ data from the grid companies.• They will then summarice this data for average statistics.

• In Future grid tariffs will depend on the supply quality.


What is measured where ?

20kV (or 30kV) 110kV 380kV230 V (400 V)

Voltage variationsFlickerHarmonicsFrequencyInterharmonicsHigher Harmonics (2-9 kHz)Fault Recording

Voltage variationsFlickerHarmonicsFrequencyInterharmonicsFault Recording

Fault RecordingHarmonicsFrequency

Fault RecordingFrequency


Data to be collected (1)

• EN 50160– U rms– frequency– U harmonics

(up to 25th)– U interharmonics– THD (total harmonic

distortion up to 40)– unbalance– flicker (long term)– voltage Dips– over-voltage– signal voltage



• Additional for Harmonics– Harmonics up to 50 (for windmills up to 100)– Flexible grouping methods of the bins (today: +/- 1 bin,

old: only the base line)– New in 61000-4-7: Frequency groups between 2 to 9

kHz (200 Hz groups)



• Flicker requirements:– Pst in 10 min– Plt in 2 h– For both: sliding windows and adjustable intervals for service and

adjustment work– New: flicker emission (current flicker)– New: flicker direction



• Power measurement:– P, Q, S, PF– Fundamental values P_h1, Q_h1, S_h1, Phi_h1– Harmonics values– Distortion power D

• Symmetrical components:– Unbalance of the fundamental– Positive, negative and zero system of U and I


Reporting the Data (1)

Diagrams:

• Min/Max/Average of the data row• Comparing the data with limits

– (absolute and relative)• Quantile values for 95%, 99%, 100%, any other value to

be open for coming standards (e.g. EN50160)• Different limits for different quantile values• Histogram curves in different styles• Statistical values like MOD, VAR, STDDEV, etc.• Energy lines (Energy consumption as time line)• Sorted data lines (e.g. of power for energy management)• Individual mathematical analysis of data lines



FFT:

• Standard FFT• FFT with limits• Limits user definable• FFT with selectable number of bins

– (e.g. old IEC 61000-4-7)

• Frequency bands (e.g. 2-9kHz@200Hz)• FFT of voltage (phase and line), current• FFT of power, reactive power incl. sign



Faults:

• List of transients• Transient curves• Evaluated transients = events (duration and height)

• DISDIP statistics• CBEMA / ITIC curve• Combined diagrams and statistics• Individual mathematical analysis of transients• FFT of transients



What else ?

• Report Generator

• Topologic View

• E-Mail Support


Renewable Energy

Renewable Energy:

• Wind power plants• Photopholtaic• …

• Own PQ rules and needs


Wind Power Plants

• What makes wind mill measurements special ?

• 1. Parameters of EN50160: – connecting wind farms to the

public grid

• 2. Parameters of 61400-21: – type testing of wind mills


Windpark EN50160

• Example:– EN50160: wind farm monitoring

at BEWAG (Austria)


Example Bewag

• They need to monitor the Quality in their whole grid (Regulation rules)

• Different needs for different voltage levels and windparks– 110 kV: Faultrecording, voltage recording…– 20 kV: PQ according EN50160, power, …– Wind: 20 kHz bandwidth, parameters of

IEC 61400-21, Flicker, Flickeremission…


Wind: IEC 61400-21

• Testing (comissioning) of PQ parameters of a wind mill and wind farms

– Harmonics– Frequency 2-9 kHz @ 200Hz– Power pins for different windspeed– Flicker emission


Tests of 61400-21• Parameters at different Wind speed

– From cut in wind speed to 15m/s in steps of 1

– Flickeremission– Flickercoefficient

• Parameters at different Power pins– 10%,20%,…80%,90%,100% P Nenn

– Max of P, Q, PF (200ms, 1min, 10min)– Max Harmonics of currents– Max Interharmonics of currents– Max HF of currents (higher harmonics 2-9kHz@200Hz)

• Voltage Variations– Behaviour of wind mill


Wind: Online evaluation


Grid Connection

Wind farms in Austria and Europe

• Typical grid connection


Grid Connection of Wind farms

At the beginning:

• Single wind mills in MV grid• Wind power was growing

• Troubles with voltage varations and flicker came up

Solution

• Combining wind mills to wind parks• Bringing power more to „higher short circuit power“


Austria and Windfarms

Most of the wind power is here (~1 GW)



20kV (30kV) 110kV 380kV

typical 2 MW

typical 20 MW

other Loads

typical > 80 MW

Loadbalancing



• Typical size of Wind mill: 2 MW• Typical Wind farm: 10 mills = 20 MW• Eastern Austria: several wind farms

• Single Wind mills: directly connected to MV distribution cable (typ. 20 kV)

• Wind farms: directly on MV transformer• More Wind farms: have an own 20 kV/110kV transformer

• Load balance with hydro power pump stations on 380 kV level


Load Balancing

Hydro Power Pump Stations for Load Balancing in the mountains

380kV



POWER PRODUCT LINE

PMPower Measurement

PNAPower Network

Analysers

PFRPower Fault Recorders

Motor TestTrafo TestHybrid Cars400 Hz Test (US)

PQ measurement

Demand measurement

Windmill testing

Substation monitoring

HVDC Line monitoring

Railway energy supply


Conclusions• PQ monitoring is a must in the future.• It is still to define how common reports and procedures

shall look alike.• The requirements differ from case to case and different

instruments can deliver different data.• Combined instruments which can give PQ data, fault

data, energy flow, etc. seem to be the future. • Central servers that provide the data to different

departments will be used. • Completely automated data exchange between the grid

company, the regulatory body and the customer is from the technical point of view possible but requires more defined data formats and reporting types.

• Renewables require special measurements and monitoring.

• The producers of these instruments are well prepared for this challenge.



Thank you for your attention

Seoul 2009 09

Dr. Werner Schoeffer

DEWETRON GmbH

Parkring 4, A-8074 Grambach

E-mail: [email protected], Phone: +43 316 3070 125

Nr. 1 POWER PRODUCT LINE DEWETRON - Power Product Line PQ System installation and evaluation of Wind Power Plants in Europe Seoul 2009 09 Dr. Werner Schoeffer.

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