Download electromagnetic topology

Electromagnetic
Compatibility Test for CMS
Experiment.
Authors
C. Rivetta– Fermilab
F. Arteche , F. Szoncso, - CERN
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 – 2 / 21
8th 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 – 3 / 21
8th 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 – 4 / 21
8th 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
CDNs
 Present stable a well defined
impedance
 Standardise the measurements of
test
 Values estimated from power cables
– Protect auxiliary equipment
– Values specified by the
standards
– HF - Characteristic Impedance (CM &
DM )
 Different from commercial LISN
– Couple EUT - Measuring
equipment.
– Standardise the measurement to 50
Ohms
EMC Test for CMS experiment – 5 / 21
8th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
2. COMMON IMPEDANCE LISN & CDNs
 LISN HCAL
Sub-System
Zcm =13 Ohms
Zdm =42 Ohms
EMC Test for CMS experiment – 6 / 21
8th 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
Measurement
equipment
 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.
EMC Test for CMS experiment – 7 / 21
LISN
Power
supply
unit
Zm
EUT
8th 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 – 8 / 21
8th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
3.EMISION TEST - RF conducted noise
 Power Supply
EMC Test for CMS experiment – 9 / 21
 FEE
8th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.EMISION TEST - RF conducted noise
EN-55022
 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
EMC Test for CMS experiment – 10 / 21
8th 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 – 11 / 21
8th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - RF conducted noise
Voltage DM
measurement
 Three different set-ups
– DM configuration
 9 kHz / 14 kHz up to 100
MHz
LISN
Current DM
measurement
– CM at HF configuration
 10 kHz up to 100 MHz
– CM at LF configuration
LISN
 (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
EMC Test for CMS experiment – 12 / 21
Injection of
CM current
Current CM
measurement
Voltage DM
measurement
LISN
Voltage CM
measurement
8th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - RF conducted noise Example
I1
ICM
 CM
12.05 µA
12 V
I12  I CM  I DM
I DM
I1  I 2

2
EMC Test for CMS experiment – 13 / 21
8th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - RF conducted noise Example
 I1
 CM
0.41mA
IDM
EMC Test for CMS experiment – 14 / 21
ICM
8th 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 – 15 / 21
8th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002
4.IMMUNITY TEST - Surge immunity Test
 The amplitude of the
signal
Trans-absorb
– Standards
 Electrical environment
– 5 Different Class
Filter
0.5 , 1kV , 2 kV, 4 kV
– For CMS values
 Counting Room - Detector
– Class 3 or 4 - (1kV-4 kV)
 Balconies - Detector
– Not clear
FEE
 Test simulation for 3
different amplitudes
– 1 kV , 500 V , 100 V
– Line - Line
EMC Test for CMS experiment – 16 / 21
CDNs
8th 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
83 V
45 V
15 V
17 kW
4.5 kW
 Final selection based on:
– Preliminary studies
– Reliability.
– Cost
– Risk
EMC Test for CMS experiment – 17 / 21
0.3 kW
8th 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 – 18 / 21
8th 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
14 V
 A simple Capacitor
protects to FEE from
this emission
 Test simulation
– 3 different RF capacitors
9V
 5nf, 500nf, 1000nf
– Line - Ground
– Amplitude
 Class 3 - 2 KV.
8.5 V
EMC Test for CMS experiment – 19 / 21
8th 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 – 20 / 21
8th 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
EMC Test for CMS experiment – 21 / 21
8th Workshop on Electronics for LHC Experiments
COLMAR - France, 9-13 September 2002