How to perform conducted immunity measurements

according to 61000-4-6 and how to validate the setup

Frédéric Pythoud, Emrah Tas EMC Europe 2016

(5. to 9. of September)

Agenda

1. Introduction on electromagnetic fields

2. Principles of conducted immunity testing

3. The setup and important issues

4. Validating with the METAS Round-Robin test device

5. Conclusion

09/09/2016 METAS 2

09/09/2016 METAS 3

1.1 Maxwell’s equations

Faraday’s induction law

Ampere-Maxwell law

Electrostatic law

Equation of magnetism

t

HErot

jt

EHrot

Ediv

0Hdiv

d

rr

crrtrjA

,

4

Equations

Solution

ArotH

dtjHrotEt

1

Retarded magnetic

vector potential

currents

James Clerk Maxwell (1831–1879)

distances

Time dependence

09/09/2016 METAS 4

1.2 Interpretation

Electric currents Electromagnetic

Waves Electric currents

E

H

i1

i2

09/09/2016 METAS 5

Immunity testing is important.

2.1 Immunity testing

The mobile phone might disturb

an electric/electronic equipment Disturbance

09/09/2016 METAS 6

2.2 Coupling mechanisms of em-waves

Shield

control

cable

currents

09/09/2016 METAS 7

2.3 Coupling to the enclosure and to cables

Coupling mostly of short

wavelength

(wavelength < 3 m)

Frequency > 80 MHz

Coupling mostly longer wavelength

(wavelength > 3 m)

Frequency < 80 MHz

09/09/2016 METAS 8

Fields are produced by antennas:

For small wavelength (< 3 m), small antennas (< 3 m)

For large wavelengths (> 3 m), large antennas (> 3m)

2.4 How fields are produced

09/09/2016 METAS 9

2.5 Basic idea of conducted immunity testing

Inject the current

directly on the cables

09/09/2016 METAS 10

Coupling-Decoupling Networks

EM-clamps

Current probes

Direct injection (on shield)

2.6 Devices to inject current on the cables

09/09/2016 METAS 11

3.1 The experimental setup

Equipment

Under

Test AE AE

AE

AE

Decoupling

Decoupling

Decoupling

Decoupling 150 Ω

Generator

A current has to flow

through the EUT

Isolation

IEC 61000-4-6 Standard

“ Testing and measurement techniques –

immunity to conducted disturbances,

induced by radio-frequency fields”

09/09/2016 METAS 12

Adapted coupling

Adapted decoupling

Signal level calibration

Correct parameters on generator

Amplifier not in compression

Correct isolation

3.2 Important points

09/09/2016 METAS 13

3.3 Possible source of errors illustrated

Equipment

Under

Test AE AE

AE

AE

Decoupling

Decoupling

Decoupling

Decoupling 150 Ω

Generator

Isolation

• Correct level setting

• No compression

• Correct parameters

80% Modulation

• Proper coupling

• and decoupling

• Correct cable

length

• Proper coupling

• and decoupling

• Decoupling only

• Proper isolation

09/09/2016 METAS 14

Special developed «EUT» to be tested

4.1 Checking the testing capabilities with a round robin test device

09/09/2016 METAS 15

Recording of the current on all interfaces during testing

Information is stored on a Micro SD card in CSV file format

Data logs are evaluated with Mathematica /MATLAB

The device can also simulate errors (red light in front)

4.2 Typical capabilities of test device

09/09/2016 METAS 16

7 signal channels used for current level measurements

Special current clamp for frequency counting

Data logging and frequency information with Arduino boards

4.3 Device Architecture and Characteristics

09/09/2016 METAS 17

4.4 The device is useful for identifying incorrect testing

Open Circuit

No 150 Ω

Outstanding overview of the device in the

EMC Europe 2016 presentation / proceedings:

“Proficiency Testing for Conducted Immunity with a new Round Robin Test Device”

Emrah Tas et al.

09/09/2016 METAS 18

Conducted immunity testing according to

IEC 61000-4-6 is not straightforward.

It requires:

• Adapted equipment

• Proper calibration

• Know-how to build up the setup

5.1 Conclusion

09/09/2016 METAS 19

The Round Robin test device developed within the scope of

this project offers a unique way to check the testing capabilities

of the laboratory

It is useful for

• Accreditation (ISO 17025)

• Teaching purposes

• To identify faulty components

Note: ISO 17025 requires inter-laboratory testing (see clause 5.9.1. b.):

“General requirements for the competence of testing

and calibration laboratories”

5.2 Possibility to check using the round robin test device

09/09/2016 METAS 20

METAS will provide international proficiency testing in the field

of EMC testing

Including following measurement places:

• IEC 61000-4-3

• IEC 61000-4-5

• IIEC 61000-4-6

• Radiated and conducted emissions according to CISPR 16

in the frequency range 150 kHz to 6 GHz.

Start in 2017

5.3 PT-Provider

Thank you very much for your attention Special thanks to all project participants