Didier Willery Pascal Garbe Toutes les PLANTES BELLES ET ...
1 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe /...
Transcript of 1 Institut für Grundlagen der Elektrotechnik und Messtechnik Prof. Dr.-Ing. Heyno Garbe /...
1Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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 MesstechnikUniversität Hannover
E-mail: [email protected]
2Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Overview
• Introduction – Description of the problem• Interference scenario• Derivation of limits (CISPR 16-4-4)• Idea and description of new measurement techniques• Results of STSM Barcelona/Hannover• Conclusions – new interesting work that has to be done
3Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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!
4Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Mains used for telecommunication network
Modem
Modem
220 V Netz
Fed with DM-Mode Conversion to CM
Conversion to CM
RJ-45 orUSB to PC
RJ-45 orUSB to PC
5Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Problems and known effectsObservations:• 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?
6Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Common mode current development
PLCModem
PLCModem
Radiation
power-line
symmetricalfeeding(DM-current)
aymmetricalstructure(CM-current)bad symmetry
changing impedanceresonances...
Fed withdifferential mode
Partially convertedto common mode
7Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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!
8Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Interference scenario
broadbandtelecommunication
service
Short-wave Service(e.g. broadcast)
What is the interference scenario?
Coupling Line guided interferenceField guided interference Transferfunction?
9Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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
10Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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
11Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Problem• The limits used today have partially been defined in
1930.• 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.
12Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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?
13Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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 16-4-4 gives hints for the derivation of limits
based on 10 influencing factors even under consideration of broadband services
=> Rational derivation of limits.
14Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Influencing factors of CISPR 16-4-4Quantification of probability• Derivation of limits – just a value with a specified
probability of a reception without disturbance.
R actual signal-to-interference ratio, Rp Protection ratio
1. Simultaneous use of interference source and victim2. Use of the same frequency3. Use in a distance, that will allow disturbances4. Full use of limits over large frequency ranges
2 2 2 2 2 2Limit w m p z a c β u α w m u z a cU R t t
R R P;P R R
15Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Interference scenario CISPR 16-4-4
Where is the back path for the common mode current?
16Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Worst case: Receiver with indoor antenna!
0 5 10 15 20 25 30-10
0
10
20
30
40
50
60
70Measurement with dipole antenna (Comb.-Gen. CM)
f / MHz
U /
dBµV
without mains / without chokewith mains / without choke
0 5 10 15 20 25 30-10
0
10
20
30
40
50
60
70Measurement with rod antenna (Comb.-Gen. CM)
f / MHz
U /
dBµV
without mains / without chokewith mains / without choke
Dipole outdoor antenna Indoor rod antenna
17Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Model of the transmission (channel model)
Description with 2- and 4 port devices
Generator with
Feeding
(source)
Mains with
sockets
(channel)
Radio with
powersupply
(victim)
18Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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?
19Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Expansion of the model
Generator withfeeding(source)
Mains network with the used socket
Radio with power supply(victim)
All 3 components have to be described in detail!
? ??
20Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Expansion of the model
Netz
21Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Differential mode feeding
49 W
RX-Chassis
22 nF
L
PE
N
Receiver/Radio-Dummy
Rod-antenna
Coupling-network
MainsGenerator
22 nF
Common-mode chokeCurrent-Balun
SymmetryVoltage-Balun
Feeding-Network
Isym,in
Iasym,out
sym,insym/asym 10
asym,out
20 logI
dI
22Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Common mode feeding
49 W
RX-Chassis
22 nF
GeneratorCounter-poise
L
PE
N
Receiver
Rod-antenna
Feeding-network
Coupling-network
Mains
49 W22 nF
Iasym,outIasym,in
asym,inasym/asym 10
asym,out
20 logI
dI
23Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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?
24Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Receiver chassis: Flow of current
rod-antenna
ICM
Receiver
ICM,Antenna
ICM,Chassis
Receiver
Rod antennaCoupling
network to mains
25Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Feeding with comb-generator
Generator
Counterpoisecurrent-probe
Generator
CM-chokebalun
mains
Common mode feeding Differential mode feeding
26Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Attenuation CM in / CM out
0 5 10 15 20 25 300
10
20
30
40
50
60
70
80
90
100DCM/CM - mit Netzverbindung
f / MHz
Das
ym /
dBWald (norm. Wohnung)Stadt (Altbau)Kantstraße (leeres Haus)
27Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Attenuation DM in / CM out
0 5 10 15 20 25 300
10
20
30
40
50
60
70
80
90
100DDM/CM - mit Netzverbindung
f / MHz
Dsy
m /
dBWald (norm. Wohnung)Stadt (Altbau)Kantstraße (leeres Haus)
28Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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
0,symsym/asym 10
1
20 logU
MDFU
0,asymasym/asym 10
1
20 logU
MDFU
29Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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. (ICM‑VNetw) /
(IN‑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. (ICM-Mains) and sym. (IN-Mains) currents will change significantly due to the frequency dependent impedance of mains network and the resulting influence on the balun.
30Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Measurement with AMN
0 5 10 15 20 25 3070
75
80
85
90
95
100
105
110
115
120
f / MHz
Measurement with Signalgenerator (sym. feeding)
UV-Netw / dBµVIN-VNetw / dBµAIN-Mains / dBµA
0 5 10 15 20 25 3040
50
60
70
80
90
100
110
f / MHz
Measurement with Signalgenerator (asym. feeding)
UV-Netw / dBµVICM-VNetw / dBµAICM-Mains / dBµA
Differential mode feeding Common mode feeding
31Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
STSM - Measurement Setup
32Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Common mode currents on cabling
0 5 10 15 20 25 3015
20
25
30
35
40
45
50
55
60
65PC LAN Side - PLC off
f / MHz
I / d
BµA
KeyboardMainsMouseLANMonitor
0 5 10 15 20 25 3015
20
25
30
35
40
45
50
55
60
65PC LAN Side - PLC on
f / MHz
I / d
BµA
KeyboardMainsMouseLANMonitor
33Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Impedance measurement with VNA
34Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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
35Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Long term – Mains – Country side/City
0 5 10 15 20 25 30-30
-20
-10
0
10
20
30
40Rauschmessung K
f / MHz
I / d
BµA
0 5 10 15 20 25 30-30
-20
-10
0
10
20
30
40Rauschmessung M
f / MHz
I / d
BµA
Country side City
36Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Long term – Mains – Country side/City
0 5 10 15 20 25 30-20
-15
-10
-5
0
5
10Rauschmessung K
f / MHz
I / d
BµA
0 5 10 15 20 25 30-20
-15
-10
-5
0
5
10
15Rauschmessung M
f / MHz
I / d
BµA
Median
37Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Long term – Mains – Country side/City
0 5 10 15 20 25 300
2
4
6
8
10
12
14
16Standardabweichung der Rauschmessung K
f / MHz
I / d
BµA
0 5 10 15 20 25 300
2
4
6
8
10
12
14Standardabweichung der Rauschmessung M
f / MHz
I / d
BµA
Standard deviation
38Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Long term – Mains – Country side
39Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Long term – Mains – City
40Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Measurement with outdoor antenna
Country side City
41Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
• A lot of work has to be done!
• But a real interesting one!
42Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Used frequency ranges - ISDN
VDSL => will even use 20-30 MHz!
43Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Used frequency ranges - PLC
Measured antenna feed-point voltage
44Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Source
45Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Connection – the line
46Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
victim
47Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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
48Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Longitudinal Conversion Loss
Feed the voltage EL and Measure VT.
Measurement ?
)log(20T
L
VE
LCL
49Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Measurement adapter
50Institut für Grundlagen der Elektrotechnik und MesstechnikProf. Dr.-Ing. Heyno Garbe / Dipl.-Ing. Sven Battermann
Longitudinal Conversion Loss
Industry area Old house installation
51Institut für Grundlagen der Elektrotechnik und MesstechnikProf. 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...