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1 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann COST 286 Workshop 'Impact of Communications.

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Präsentation zum Thema: "1 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann COST 286 Workshop 'Impact of Communications."—  Präsentation transkript:

1 1 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann COST 286 Workshop 'Impact of Communications Technology to EMC' PLC - Measurement of Mains Characteristics Sven Battermann, Heyno Garbe Institut für Grundlagen der Elektrotechnik und Messtechnik Universität Hannover

2 2 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Overview Introduction – Description of the problem Interference scenario Derivation of limits (CISPR ) Idea and description of new measurement techniques Results of STSM Barcelona/Hannover Conclusions – new interesting work that has to be done

3 3 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Broadband communication networks with Primary task => Data transmission –LAN –DSL / ADSL / VDSL –... with Secondary task => Data transmission –PLC –ISM-Applications – e.g. configuration of power drives –...  Totally different electrical characteristics of the used cables / lines!

4 4 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Mains used for telecommunication network Modem 220 V Netz Fed with DM-Mode Conversion to CM RJ-45 or USB to PC RJ-45 or USB to PC

5 5 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Problems and known effects Observations: For EMC: Radiation data rate decreases with distance from feed point Different data rates in different rooms influence of load condition (used devices) Operation of “special” devices also decreases data rate Questions:  What are the reasons for this phenomenal experiences?  What is the particular disturbance scenario?  Quantification of mains influence possible?

6 6 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Common mode current development

7 7 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann What is the problem with CM-currents? Two differential mode signals (DM also symmetric current) with 180° phase shift compensate! => low radiation The common mode signal (CM also asymmetric current) will be radiated – without compensation! Problem: The fed DM-signal converts to a CM-Signal, if there are any asymmetries!

8 8 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Interference scenario broadband telecommunication service Short-wave Service (e.g. broadcast) What is the interference scenario? Coupling Line guided interference Field guided interference Transferfunction?

9 9 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Interference scenario - victim What is the impact of a common mode current on a connected device (receiver)? Ed Hare: Radio frequency interference Power Supply – mains network

10 10 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann CM-current in the input circuit The common mode current flows through the input circuit of the receiver -> voltage drop at the input resistor -> interference

11 11 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Problem The limits used today have partially been defined in At that time narrowband interferers (transmitter) and stochastic broadband interferers (e. g. electric motors) have been known. Different situation today: –Many telecommunication-services use a broadband spectrum up to the short-wave band. –Different services are always on, therefore they are no stochastic interferers anymore.

12 12 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Influence on the limits? The limits (1930) are derived from the old interference scenario. The interference scenario changed significantly. Questions: Is it possible to model the situation today (with broadband telecommunication services) with the old interference scenario? It is reasoned to use the old limits, based on a different scenario for the interference scenario today? Is it possible to safeguard the radio services?

13 13 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Derivation of Limits It has to be expected that the use of the full limits of CISPR 22 cannot safeguard the protection of radio services anymore! What has to be done: For a valid protection of radio services a detailed analysis of the interference scenario is necessary. CISPR gives hints for the derivation of limits based on 10 influencing factors even under consideration of broadband services => Rational derivation of limits.

14 14 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Influencing factors of CISPR Quantification of probability Derivation of limits – just a value with a specified probability of a reception without disturbance. R actual signal-to-interference ratio, R p Protection ratio 1.Simultaneous use of interference source and victim 2.Use of the same frequency 3.Use in a distance, that will allow disturbances 4.Full use of limits over large frequency ranges

15 15 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Interference scenario CISPR Where is the back path for the common mode current?

16 16 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Worst case: Receiver with indoor antenna! Dipole outdoor antennaIndoor rod antenna

17 17 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Model of the transmission (channel model) Description with 2- and 4 port devices

18 18 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Measurements to be performed… What is a reasonable measurement setup? It is a „simple“ measurement problem – we just want to know the attenuation of the mains network between source and victim -> Mains Decoupling Factor -> Mains Attenuation Factor Two port network analyser -> that’s it! – Really?

19 19 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Expansion of the model Generator with feeding (source) Mains network with the used socket Radio with power supply (victim) All 3 components have to be described in detail! ? ??

20 20 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Expansion of the model

21 21 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Differential mode feeding

22 22 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Common mode feeding

23 23 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Reasons for these measurements Why currents – what about well known CDNs with disturbance voltage measurement? –Is the voltage the reason for the disturbance? –What is the influence of the difference between CDN impedance against real mains impedance? Why don‘t you use a typical balun for telecommunication lines? –Do we have 120 Ohm? –Have you ever checked the characteristics of your balun with other loads than 120 Ohm?

24 24 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Receiver chassis: Flow of current Receiver Rod antenna Coupling network to mains

25 25 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Feeding with comb-generator Generator Counterpoise current- probe Generator CM-choke balun mains Common mode feedingDifferential mode feeding

26 26 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Attenuation CM in / CM out

27 27 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Attenuation DM in / CM out

28 28 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Mains Decoupling Factor Measured voltage at the radio dummy for both feedings Normalized to the measurement voltage on the AMN

29 29 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Difference – Mains decoupling factor The constant impedance of the V-network is an ideal load for the balun. The measurements of the fed asym. to sym. (I CM ‑ VNetw ) / (I N ‑ VNetw ) current and the measured disturbance voltage at the V-network will show a minor frequency dependence. When the source will be connected with the mains the asym. (I CM-Mains ) and sym. (I N-Mains ) currents will change significantly due to the frequency dependent impedance of mains network and the resulting influence on the balun.

30 30 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Measurement with AMN Differential mode feedingCommon mode feeding

31 31 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann STSM - Measurement Setup

32 32 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Common mode currents on cabling

33 33 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Impedance measurement with VNA

34 34 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Conclusions Why doing near field measurements? – try to measure the most important quantity for the disturbance -> Current Measurement Setup was presented during CISPR meeting in South Africa – (-> accepted! - Draft) What has to be done: –noise floor measurements with radio dummy –more attenuation measurements of mains networks

35 35 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Long term – Mains – Country side/City Country sideCity

36 36 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Long term – Mains – Country side/City Median

37 37 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Long term – Mains – Country side/City Standard deviation

38 38 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Long term – Mains – Country side

39 39 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Long term – Mains – City

40 40 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Measurement with outdoor antenna Country sideCity

41 41 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann A lot of work has to be done!  But a real interesting one!

42 42 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Used frequency ranges - ISDN VDSL => will even use MHz!

43 43 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Used frequency ranges - PLC Measured antenna feed-point voltage

44 44 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Source

45 45 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Connection – the line

46 46 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann victim

47 47 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Measurements First idea was the measurement of LCL and TCL Derived from good results with telecommunication cables

48 48 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Longitudinal Conversion Loss Feed the voltage E L and Measure V T. Measurement ?

49 49 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Measurement adapter

50 50 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Longitudinal Conversion Loss Industry areaOld house installation

51 51 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann Is LCL sufficient? A lot of LCL measurements have been performed all over the world. It is the correct quantity to describe the interference scenario? Let us try to model the interference scenario...


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