electromagnetic compatibility test for cms experiment. authors c. rivetta– fermilab f. arteche, f....

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



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.



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).



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



2. COMMON IMPEDANCE LISN & CDNs

Zdm =42 Ohms

Zcm =13 Ohms

LISN HCAL Sub-System



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



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




Power Supply FEE




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



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



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



4.IMMUNITY TEST - RF conducted noise - Example

12.05 µA

CMICM

I1

221

12

III

III

DM

DMCM

12 V



4.IMMUNITY TEST - RF conducted noise - Example

I1 CM

0.41mA

IDM ICM



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



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



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



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.



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



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



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

electromagnetic compatibility test for cms experiment. authors c. rivetta– fermilab f. arteche, f....

Documents

conclusionsioup98u9jioemc

noise immunity test

standardsioup98u9jioemc

noisegoal of test

cms experiment

emision test rf

cern ioup98u9jioemc

immunity testrf