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: werner.schoeffer@dewetron.com, Phone: +43 316 3070 125

Quality characteristics of Power 1. 230 V (220 V, 110V or different) 2. AC - sinewave 3. 50 (60) Hz 4. 3 phases 5. Availability

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 50160 EC-directive 85/374 – standardization of the product liabilty laws Electricity became a product Quality characteristics for the product Electricity (voltage) have been used EN 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) frequency 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%)

EN 50160 (2) 230 V~ phase voltage (line to earth, lower voltage grid) transmission grid: 1 kV to 35 kV line to line voltage (must be defined) (attention: until 2006: 220 V)

EN 50160 (3) slow voltage variations MV+LV: 95% of the 10min-avg values have to be in the range of +/-10% U LV: 100% of the 10min-avg values have to be in the range of +10/-15% U

EN 50160 (4) fast voltage fluctuations and flicker Low voltage: <5% 10ms (up tp 10%) Medium voltage: <4% 10ms (up to 6%) Flicker: PLT=1 in 95% of a week

EN 50160 (5) Voltage dips dips: <60% , 10-1000 per year

EN 50160 (6) interruptions short: < 1sec, 10-100 per year long: < 3 min (30% of counted short)

EN 50160 (7) voltage drop out Very long interruptions: > 3 min, 10-50 per year Proclaimed (in case of service): always

EN 50160 (8) net frequent over voltages: LV: <440V@5sec; < 1,5 kV short circuit MV: <1,7 – 2*Uc

EN 50160 (9) Transients Lower voltage: <6kV

EN 50160 (10) unsymmetry in 95% of a week

EN 50160 (11) Harmonics @95% of a week THD < 8% harmonics in detail Others (up to 25): 0,5%

EN 50160 (12) interharmonics not defined But: flicker

EN 50160 (13) Telegram voltages frequency depending limit curve

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 ? 230 V (400 V) 20kV (or 30kV) 110kV 380kV Voltage variations Flicker Harmonics Frequency Interharmonics Higher Harmonics (2-9 kHz) Fault Recording Voltage variations Flicker Harmonics Frequency Interharmonics Fault Recording Fault Recording Harmonics Frequency Fault Recording Frequency

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

Data to be collected (2) 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)

Data to be collected (3) 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

Data to be collected (4) Power measurement: Symmetrical components: 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

Reporting the Data (2) 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

Reporting the Data (3) 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

Reporting the Data (4) 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)

Grid Connection of Wind farms 20kV (30kV) 110kV 380kV typical 2 MW other Loads typical 20 MW Load balancing typical > 80 MW

Grid Connection of Wind farms 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

DEWETRON - Power Product Line

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.

DEWETRON - Power Product Line Thank you for your attention Seoul 2009 09 Dr. Werner Schoeffer DEWETRON GmbH Parkring 4, A-8074 Grambach E-mail: werner.schoeffer@dewetron.com, Phone: +43 316 3070 125