Post on 05-Jan-2016
Electromagnetic Compatibility Test for CMS
Experiment.
Authors
C. Rivetta– Fermilab
F. Arteche , F. Szoncso, - CERN
EMC Test for CMS experiment – 2 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
OUTLINE 1.Introduction 2. Common Impedance
– LISN.
– CDNs. 3.Emission Test
– Harmonics.
– RF conducted emission test. 4.Immunity Test
– RF conducted noise immunity test.
– Slow transients - Surge immunity test.
– Fast transients - Burst immunity test.
– Voltage dips and short voltage interruptions immunity test 5.Conclusions
EMC Test for CMS experiment – 3 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
1.INTRODUCTION EMC phenomena are present in CMS
– Noise generated by DC-DC converters Common mode & Differential mode
– Transients Over-voltages
– Induced via magnetic fields
Load changes Switching
– Voltage variations
– Harmonics
It is important to measure & control them Goal of these tests
– Get the levels of “emission” and “immunity” Identify possible EMC problems.
EMC Test for CMS experiment – 4 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
1.INTRODUCTION Generic, Basic and military Standards & Aerospace rules.
– There are a lot of standards For practical reasons “ we only consider some of them “
Emissions test– RF conducted noise (based EN-55011-22 // MIL-STD-461// IEEE Std 1515)
CM & DM ( high and low frequency)
– Harmonics (based EN- 61000-3) Special for 400 Hz power supply distribution system (very low)
Immunity test– Immunity to RF conducted noise (based EN-61000-4-6)
– Electrical fast transient burst immunity test (based EN-61000-4-4).
– Surge immunity test- Over-voltage (based EN-61000-4-5).
– Voltage dips, short interruptions and voltage variations immunity test (based EN-61000-4-11).
EMC Test for CMS experiment – 5 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
2. COMMON IMPEDANCE LISN & CDNs
Two kinds of common impedance– Line Impedance Stabilisation Network (LISN)
– Coupling De-coupling Network (CDNs)
LISN Present stable a well defined
impedance Standardise the measurements of
test Values estimated from power cables
– HF - Characteristic Impedance (CM & DM )
Different from commercial LISN– Couple EUT - Measuring
equipment.
– Standardise the measurement to 50 Ohms
CDNs– Protect auxiliary equipment
– Values specified by the standards
EMC Test for CMS experiment – 6 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
2. COMMON IMPEDANCE LISN & CDNs
Zdm =42 Ohms
Zcm =13 Ohms
LISN HCAL Sub-System
EMC Test for CMS experiment – 7 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
3.EMISION TEST - Harmonics Effects by pulling the current from
power main for only a part of the cycle
– Typically rectifiers ( we have 400 Hz power distribution)
Implications
– Quality power distribution.
– Power supply distribution over-design Power transformers over-stress Equipment overheat
Oriented to the 400 Hz PS distribution
– AC-Dc converters
– Transformers Limits of harmonics based on
international standards & studies.
Power supply
unitEUT
Measurement equipment
ZmLISN
EMC Test for CMS experiment – 8 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
3.EMISION TEST - RF conducted noise
Goal of test control the conducted emission level– Power Supplies & FEE
– Frequency Range 9 kHz - 50 MHz Conducted emissions – Propagation
– Common Mode Group of conductors and ground or other conductors.
– Differential Mode Conductor pairs (Negative-Positive or Phase-Neutral)
– Abundant energy exchange between modes CM - DM conversion
System topology as close as possible to final one– Common impedance LISN
Equipment used Current probes & Spectrum Analyser
EMC Test for CMS experiment – 9 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
3.EMISION TEST - RF conducted noise
Power Supply FEE
EMC Test for CMS experiment – 10 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.EMISION TEST - RF conducted noise
Test Results Power Supplies– Input
Results refereed to 50 Ohm to compare them with the standards
We used EN - 55022 B
– Output There is no standards so we
need to generate them
– From this values and the values from Immunity test
FEE– Input
Results refereed to 50 Ohm to compare them with the standards
EN-55022
EMC Test for CMS experiment – 11 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST- RF conducted noise
Electromagnetic immunity is the ability,of a device equipment or system to perform without degradation in presence of electromagnetic disturbances
Goal of these tests
– Immunity level of FEE and PS to conducted disturbances.
Injection of conducted noise to the FEE– Common impedance - LISN
The idea is inject signal and measure pedestal – Identify frequency areas where the pedestal is not valid
– This test will define sensible areas of the FEE
Injection via current probes– It is recommended to Voltage & Current
EMC Test for CMS experiment – 12 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - RF conducted noise
Three different set-ups
– DM configuration 9 kHz / 14 kHz up to 100
MHz
– CM at HF configuration 10 kHz up to 100 MHz
– CM at LF configuration (A few hertz up to 10
kHz)
The value of the amplitude of the signal depends on the sensitivity of the FEE.
This test is complementary of Conducted emission TEST
Current DM measurement
LISN
Voltage DM measurement
LISN
LISN
Current CM measurement
Injection of CM current
Voltage DM measurement
Voltage CM measurement
EMC Test for CMS experiment – 13 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - RF conducted noise - Example
12.05 µA
CMICM
I1
221
12
III
III
DM
DMCM
12 V
EMC Test for CMS experiment – 14 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - RF conducted noise - Example
I1 CM
0.41mA
IDM ICM
EMC Test for CMS experiment – 15 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - Surge immunity Test The goal of test - Determinate the
equipment susceptibility to damage by over-voltage generated by– Load changes /Short Circuits /Faults to
earth
Common Impedance LISN & CDNs to protect auxiliary equipment
Coupling network will be used to inject the transient
9 µf & 10 Ohms or 18 µf - Depends on the Test
Pulse Characteristic– Voltage O.Circuit 1.2/50 µs.
– Current S.Circuit 8/20 µs A Zenner / Trans-absorb protect
EUT from this emission
EMC Test for CMS experiment – 16 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - Surge immunity Test
The amplitude of the signal– Standards
Electrical environment
– 5 Different Class 0.5 , 1kV , 2 kV, 4 kV
– For CMS values Counting Room - Detector
– Class 3 or 4 - (1kV-4 kV)
Balconies - Detector
– Not clear
Test simulation for 3 different amplitudes– 1 kV , 500 V , 100 V
– Line - Line
Trans-absorb
Filter
CDNs
FEE
EMC Test for CMS experiment – 17 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - Surge immunity Test It is difficult to find a
device to dissipate this power and clamp the voltage within maximum values valid for the FEE.
Level selection– High level
Increase cost or could not have any technical solution
– Low level Increase risk of failure
by over-voltage
Final selection based on:– Preliminary studies
– Reliability.
– Cost
– Risk
83 V
45 V
15 V
17 kW
4.5 kW
0.3 kW
EMC Test for CMS experiment – 18 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - Burst immunity Test The goal of test
– Fix the susceptibility to damage by over-voltage generated by switching transients.
Common Impedance LISN & CDNs to protect auxiliary equipment.
Coupling network will be used to inject the fast transient - 33 nf.
Pulse Characteristic– Double exponential 5ns/50 ns.– Burst duration ~ 15 ms / 300 ms
(1 minute). Spectra content of signal HF.
– Layout very important. – Coupling of burst depends strongly from
parasitic capacitance.
EMC Test for CMS experiment – 19 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - Burst immunity Test
Class is not defined yet.
– Not very important A simple Capacitor
protects to FEE from this emission
Test simulation – 3 different RF capacitors
5nf, 500nf, 1000nf
– Line - Ground
– Amplitude Class 3 - 2 KV.
14 V
9 V
8.5 V
EMC Test for CMS experiment – 20 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - Voltage dips immunity Test Noise source
– Faults in the networks
– Sudden large change of load
Test on FEE – Short interruptions & Voltage variations
Test on Power Supplies– Short interruptions & Voltage variations
– Voltage dips
Common impedance LISN Test level
– Standards Voltage dips
– ( 0-40-70%) V nominal - Voltage variations
– (0 -40 % ) V nominal. -
– For us under study
EMC Test for CMS experiment – 21 / 218th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
5. CONCLUSIONS
EMC phenomena is present in CMS
– It is important to measure and control them EMC tests are based on standards and aerospace industry . EMC test will be focus on conducted noise
– Immunity and emissions test
– Only a few test will be considered due to practical reasons Test levels has not fixed yet
– It has a big influence in the elections of filters & protections
– It will depend on Technical studies Reliability Cost Risk