1. Impedance Measurement of Electrical Equipment on the Power Network
Institut
Impedance Measurement of Electrical Equipment on the Power Network
WSPLC16, Paris, France
10-11 October 2016
George Hallak Gerd Bumiller
Schrifttyp Liberation Regular
Schriftgrößen 16, 20, 24, 28, 30
Linienstärke 1 pt, 2 pt
Auf Deckblatt der Masterfolie sind in weiß Semesterbezeichnung und Seitennummer

2. Outline Problem statement Access Impedance Measurement System (AIMS)
Institut
Outline
Problem statement
Access Impedance Measurement System (AIMS)
Equipment impedance measurement procedure
Measurement results & evaluation
Conclusion

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Problem statement
The PLC channel is strongly affected by the connected equipment load impedances to the power grid.  Noise and attenuation.
The characterization of the propagation channel is mainly dependent on the load impedances, the attenuation and the electrical cables characteristics.
The exact knowledge of the load impedances enables the analysis of their behavior in respect to time and frequency.
The load impedance measurement allows the prediction of the connected loads from the classification of their behavior.

4. Access impedance measurement system
The PLC access impedance measurement system is based on V-I measurements to determine the impedance for frequencies up to 500 kHz.

5. Access impedance measurement results
No loads connected near to the measurement plug

6. Access impedance measurement results
Different load equipment are connected near to the plug
Monitor P2250
Fujitsu Laptop
Samsung TV
Oscilloscope PM3082

7. Equipment impedance measurement procedure
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Equipment impedance measurement procedure
An isolation transformer (IT) is connected to the AIMS in parallel to the device under test (DUT).
The purpose of connecting the isolation transformer to the AIMS is the high impedance representation of the transformer on the power network.
The output of the IT supplies the DUT with electricity.

8. Equipment impedance determination
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Equipment impedance determination
𝑍 𝑚 𝑓,𝑡 = 𝑍 𝐼𝑇 (𝑓) + 1 𝑍 𝐷𝑈𝑇 (𝑓,𝑡)
𝑍 𝐷𝑈𝑇 𝑓,𝑡 = − 𝑍 𝑚 (𝑓,𝑡)∙ 𝑍 𝐼𝑇 (𝑓) 𝑍 𝑚 𝑓,𝑡 − 𝑍 𝐼𝑇 (𝑓) ;
𝑍 𝐼𝑇 needs one extra measurement where only the IT is connected to the power line.

9. Impedance of the isolation transformer
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Impedance of the isolation transformer

10. Impedance of the 2 isolation transformer in series
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Impedance of the 2 isolation transformer in series
Does not work!

11. Impedance of equipment – (Open circuit, light bulb)
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Impedance of equipment – (Open circuit, light bulb)
Open circuit
Light bulb

12. Impedance of equipment – (PM3082 oscilloscope, TV)
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Impedance of equipment – (PM3082 oscilloscope, TV)
Oscilloscope PM3082
Samsung TV

13. Impedance of equipment – (Laptop, P2250 monitor)
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Impedance of equipment – (Laptop, P2250 monitor)
Fujitsu Laptop
Monitor P2250

14. Impedance measurement evaluation
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Impedance measurement evaluation
The access impedance of the power line of each connected load equipment is calculated as
𝑍 𝐴𝐸 𝑓,𝑡 = 𝑍 𝐴𝑁 (𝑓,𝑡) + 1 𝑍 𝐷𝑈𝑇 (𝑓,𝑡) ; 𝑍 𝐴𝐸 : The calculated access impedance
𝑍 𝐴𝑁 : The network access impedance
 The measured and calculated access impedances are relatively identical.
 Prediction of the connected equipment from the measured access impedance.

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Conclusion
Time and frequency dependent loads impedance measurements have been presented.
The measured equipment impedances allowed the analysis of their behavior to characterize the PLC propagation channel.
Each equipment has different behavior on the power grid. This behavior depends mainly on the switched power supply and the EMC filter.
Future works:
Measurements in field on representative devices.
Equipment behavioral classification based on their time and frequency impedances.

16. Thank you for your attention!
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Thank you for your attention!

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