1. DEWETRON - Power Product Line
PQ System installation and evaluation of Wind Power Plants in Europe
Seoul
Dr. Werner Schoeffer
DEWETRON GmbH
Parkring 4, A-8074 Grambach
Phone:

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

3. 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.

4. 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.

5. 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.

6. Standards and Regulations
EN Voltage levels in public power grids
IEC harmonics measurement
IEC flicker measurement
IEC PQ measurement methods
IEC Measurement and assessment of power quality characteristics of grid connected wind turbines

7. 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

8. EN in details

9. EN (1)
frequency
10sec-avg value, 99,5% of a year: 50Hz, +/- 1% (stand alone: +/- of a week)
100 % of a year: +4%/-6% (stand alone : +/-

10. 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)

11. 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

12. 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

13. EN (5)
Voltage dips
dips: <60% , per year

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

15. EN (7)
voltage drop out
Very long interruptions: > 3 min, per year
Proclaimed (in case of service): always

16. EN 50160 (8) net frequent over voltages:
LV: < 1,5 kV short circuit
MV: <1,7 – 2*Uc

17. EN (9)
Transients
Lower voltage: <6kV

18. EN (10)
unsymmetry
in 95% of a week

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

20. EN (12)
interharmonics
not defined
But: flicker

21. EN (13)
Telegram voltages
frequency depending limit curve

22. 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 !

23. IEC 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.

24. Additional Standards
Voltage levels in customers grids (e.g. IEC )
Emission levels of equipment (e.g. IEC 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 windmills)
Environment for IT
ITIC, former CBEMA curve
Voltage interruptions
Unipede statistics,
SAIFI, SAIDI, CAIDI, etc.)

25. 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.

26. 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

27. 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

28. 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 : Frequency groups between 2 to 9 kHz (200 Hz groups)

29. 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

30. 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

31. 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

32. Reporting the Data (2) FFT: Standard FFT FFT with limits
Limits user definable
FFT with selectable number of bins
(e.g. old IEC )
Frequency bands (e.g.
FFT of voltage (phase and line), current
FFT of power, reactive power incl. sign

33. 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

34. Reporting the Data (4) What else ? Report Generator Topologic View
Support

35. Renewable Energy Renewable Energy: Wind power plants Photopholtaic …
Own PQ rules and needs

36. Wind Power Plants What makes wind mill measurements special ?
1. Parameters of EN50160:
connecting wind farms to the
public grid
2. Parameters of :
type testing of wind mills

37. Windpark EN50160 Example: EN50160: wind farm monitoring
at BEWAG (Austria)

38. 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 , Flicker, Flickeremission…

39. Wind: IEC
Testing (comissioning) of PQ parameters of a wind mill and wind farms
Harmonics
Frequency Hz
Power pins for different windspeed
Flicker emission

40. 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
Voltage Variations
Behaviour of wind mill

41. Wind: Online evaluation

42. Grid Connection Wind farms in Austria and Europe
Typical grid connection

43. 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“

44. Austria and Windfarms
Most of the wind power is here (~1 GW)

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

46. 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

47. Load Balancing Hydro Power Pump Stations for
Load Balancing in the mountains
380kV

48. DEWETRON - Power Product Line

49. 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.

50. DEWETRON - Power Product Line
Thank you for your attention
Seoul
Dr. Werner Schoeffer
DEWETRON GmbH
Parkring 4, A-8074 Grambach
Phone: