SIST EN IEC 61757-4-3:2020

SLOVENSKI STANDARD
SIST EN IEC 61757-4-3:2020
01-november-2020
Optični senzorji - 4-3. del: Merjenje električnega toka - Polarimetrijska metoda (IEC
61757-4-3:2020)
Fibre optic sensors - Part 4-3: Electric current measurement - Polarimetric method (IEC
61757-4-3:2020)
Lichtwellenleitersensoren - Teil 4-3: Strommessung - Polarimetrisches Verfahren (IEC
61757-4-3:2020)
Capteurs fibroniques - Partie 4-3: Mesure du courant électrique - Méthode polarimétrique
(IEC 61757-4-3:2020)
Ta slovenski standard je istoveten z: EN IEC 61757-4-3:2020
ICS:
33.180.99 Druga oprema za optična Other fibre optic equipment
vlakna
SIST EN IEC 61757-4-3:2020 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 61757-4-3:2020

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SIST EN IEC 61757-4-3:2020


EUROPEAN STANDARD EN IEC 61757-4-3

NORME EUROPÉENNE

EUROPÄISCHE NORM
September 2020
ICS 33.180.90

English Version
Fibre optic sensors - Part 4-3: Electric current measurement -
Polarimetric method
(IEC 61757-4-3:2020)
Capteurs fibroniques - Partie 4-3: Mesure du courant Lichtwellenleitersensoren - Teil 4-3: Strommessung -
électrique - Méthode polarimétrique Polarimetrisches Verfahren
(IEC 61757-4-3:2020) (IEC 61757-4-3:2020)
This European Standard was approved by CENELEC on 2020-09-03. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.



European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 61757-4-3:2020 E

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SIST EN IEC 61757-4-3:2020
EN IEC 61757-4-3:2020 (E)
European foreword
The text of document 86C/1578/CDV, future edition 1 of IEC 61757-4-3, prepared by SC 86C "Fibre
optic systems and active devices" of IEC/TC 86 "Fibre optics" was submitted to the IEC-CENELEC
parallel vote and approved by CENELEC as EN IEC 61757-4-3:2020.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2021-06-03
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2023-09-03
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 61757-4-3:2020 was approved by CENELEC as a
European Standard without any modification.
2

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SIST EN IEC 61757-4-3:2020
EN IEC 61757-4-3:2020 (E)
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the
relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 61757 - Fibre optic sensors - Generic specification EN IEC 61757 -


3

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SIST EN IEC 61757-4-3:2020



IEC 61757-4-3

®


Edition 1.0 2020-07




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE











Fibre optic sensors –

Part 4-3: Electric current measurement – Polarimetric method



Capteurs fibroniques –

Partie 4-3: Mesure du courant électrique – Méthode polarimétrique
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 33.180.99 ISBN 978-2-8322-8729-3




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Components of optical current sensor using polarimetric method . 10
4.1 General descriptions . 10
4.2 Classification of Faraday elements . 11
5 Characteristic test . 12
5.1 General information . 12
5.2 Output power of light source . 12
5.3 Input power of light detector . 13
5.4 I/O characteristics . 13
5.4.1 General . 13
5.4.2 Test method . 14
5.4.3 Test procedure . 16
5.4.4 Evaluation . 18
5.5 Warm-up time . 19
5.5.1 General . 19
5.5.2 Test method . 19
5.5.3 Evaluation . 19
5.6 Current conditions for obtaining each parameter . 19
5.7 Input parameter dependency . 20
5.7.1 Frequency characteristic . 20
5.7.2 Transient characteristic . 20
5.8 External environment dependency . 22
5.8.1 Steady state temperature characteristic test . 22
5.8.2 Transient temperature characteristic test . 25
5.8.3 External magnetic field test . 27
5.8.4 Conductor position test . 28
5.8.5 Vibration test . 29
Annex A (informative) Principle of optical current sensor . 30
A.1 Outline . 30
A.2 Faraday effect . 30
A.3 Types of Faraday element . 31
A.4 Conversion of the Faraday effect into an electric signal . 31
A.4.1 Detection of the Faraday effect of nonmagnetic material . 31
A.4.2 Detection of the Faraday effect of ferromagnetic material . 31
A.5 Current detection method . 32
A.5.1 General . 32
A.5.2 Examples of current detection method . 32
Annex B (informative)  Features of optical current sensor technology . 35
Annex C (informative)  Design considerations . 36
C.1 General information . 36
C.2 Performance restricting factors . 36
C.3 Procedure for determining the specifications of the equipment . 37

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Annex D (informative)  Optical current sensor output in the application of other phase
magnetic fields. 39
D.1 Ampere's circulation integral law . 39
D.2 Influence of other phase magnetic fields . 39
Annex E (informative) Measurement parameter performance table . 41
E.1 General . 41
E.2 Output power of light source . 41
E.3 Input power of light detector . 41
E.4 I/O characteristics . 41
E.5 Frequency characteristics . 42
E.6 Transient characteristics . 43
E.7 Steady state temperature characteristics . 43
E.8 Transient temperature characteristics . 44
E.9 External magnetic field. 45
E.10 Conductor positions . 46
E.11 Vibration . 47
Bibliography . 48

Figure 1 – Measurement system using optical current sensor . 10
Figure 2 – Construction of optical current sensor . 11
Figure 3 – Classification of Faraday elements . 12
Figure 4 – Example of an optical power monitor . 13
Figure 5 – Example of the amplifying circuit of a light detector . 13
Figure 6 – I/O characteristics of an optical current sensor . 14
Figure 7 – Measurement system of waveform comparison method . 15
Figure 8 – Measurement system of AC bridge method . 16
Figure 9 – Transient characteristics of AC dedicated system . 21
Figure 10 – Transient characteristics of DC/AC system . 22
Figure 11 – Configuration example of steady state temperature characteristic test and
transient temperature characteristic test of sensor part . 24
Figure 12 – Example of temperature profile. 24
Figure 13 – Birefringence change during temperature change . 25
Figure 14 – Example of temperature programme . 27
Figure 15 – Position of the outer conductor in the external magnetic field test when the
Faraday element is an optical fibre . 28
Figure 16 – Position of the conductor in the conductor position test when the Faraday
element is an optical fibre . 29
Figure A.1 – Faraday effect. 30
Figure A.2 – Configuration of current detection method using Faraday effect . 32
Figure A.3 – Basic configuration of intensity modulation type optical current sensor . 33
Figure A.4 – Configuration example of intensity modulation type reflective optical
current sensor . 33
Figure A.5 – Configuration example of interference type optical current sensor. 34
Figure D.1 – The law of Ampere's circulation integral . 39
Figure D.2 – Image diagram of incomplete closed loop . 40
Figure E.1 – Example of the transient characteristic . 43

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Figure E.2 – Example of the temperature characteristics at current 0 . 43
Figure E.3 – Example of the temperature characteristics at rated current . 44
Figure E.4 – Example of the transient temperature characteristics at input current 0 . 44
Figure E.5 – Example of the transient temperature characteristics at rated current . 45
Figure E.6 – Positions of the outer conductor . 46
Figure E.7 – Positions of the conductor in the conductor positions test . 46
Figure E.8 – Example of the vibration test at current 0 . 47
Figure E.9 – Example of the vibration test at rated current . 47

Table 1 – List of parameters to be obtained . 12
Table 2 – Test method . 15
Table 3 – Current conditions for obtaining each parameter . 19
Table E.1 – Output power of light source . 41
Table E.2 – Input power of light detector . 41
Table E.3 – I/O characteristics . 41
Table E.4 – Frequency characteristics . 42
Table E.5 – External magnetic field . 45
Table E.6 – Conductor position . 46

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SIST EN IEC 61757-4-3:2020
IEC 61757-4-3:2020 © IEC 2020 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

FIBRE OPTIC SENSORS –

Part 4-3: Electric current measurement –
Polarimetric method

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61757-4-3 has been prepared by subcommittee SC 86C: Fibre optic
systems and active devices, of IEC technical committee TC 86: Fibre optics.
The text of this International Standard is based on the following documents:
CDV Report on voting
86C/1578/CDV 86C/1611/RVC

Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61757 series, published under the general title Fibre optic sensors,
can be found on the IEC website.

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The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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IEC 61757-4-3:2020 © IEC 2020 – 7 –
INTRODUCTION
Current measuring techniques are essential for controlling and diagnosing apparatus that
support industry and society. As current measuring devices, optical current sensors based on
magneto-optic effect have been developed. As these sensors enable advanced current
measurement free from the issues related to conventional current sensors based on
electromagnetic induction, they have been applied in various fields including power systems.
Given the expectations for the potential of this sensing technology, various kinds of optical
current sensors for various applications have been proposed by manufacturers. With this
background, there are many kinds (target current for measurement, configuration of sensor,
signal processing method, installation method) of optical current sensors for various
applications. When developing a new optical current sensor, the evaluation and design of
performance and characteristics are carried out in each case.
For promoting the dissemination of optical current sensors, it is important to define the terms
representing performance and functionality of the optical current sensor, which is manufactured
on the basis of sensing technology. It is also important to make clear how to evaluate such
terms. This makes it possible to design the sensor efficiently and properly and to transfer the
sensor smoothly from a supplier to a user by settling these issues. Under these circumstances,
a set of methods is summarized in this document for evaluating the performance and
characteristics of optical current sensors. As the required performance for a sensor depends
on its application, the performance is not defined quantitatively in this document. However, with
the help of this document, the quantitative measures of sensor performance will be defined in
designing the sensor itself in anticipation of its practical application.
This document is based on standard OITDA FS 01 published by the Optoelectronics Industry
and Technology Development Association (OITDA).

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FIBRE OPTIC SENSORS –

Part 4-3: Electric current measurement –
Polarimetric method



1 Scope
This part of IEC 61757 defines terminology, structure, and a characteristic test method of an
optical current sensor using the polarimetric method. It addresses the current sensing element
only and not the additional devices that are unique to each application. Generic specifications
for fibre optic sensors are defined in IEC 61757.
As the specifications of optical polarimetric fibre current sensors required by each user vary
depending on the application, this document does not define the required performance values.
The required performance values are defined when designing a sensor according to the specific
application.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 61757, Fibre optic sensors – Generic specification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61757 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
current conducting coil
air-core coil made of lead wires that applies electric current, which is used to apply the equal
magnetic field generated by the current to be measured to an optical fibre or a bulk-form
Faraday element when conducting a characteristic test of optical current sensor
3.2
external magnetic field
magnetic field generated from anywhere other than the conductor where the current to be
measured is passing in an optical current sensor
3.3
Faraday effect
circular birefringence that is generated when an external magnetic field is imposed on a
substance

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IEC 61757-4-3:2020 © IEC 2020 – 9 –
Note 1 to entry: The Faraday effect is a kind of magneto-optical effect. "Magneto-optical effect" is a general term
that means the effect of a magnetic field on the optical characteristics of particles or crystal. In addition to the Faraday
effect, there are other magneto-optical effects such as the Zeeman effect, magnetic birefringence, magnetic circular
dichroism, the magnetic Kerr effect, and magneto-oscillatory absorption.
3.4
Faraday element
optical element for detecting Faraday effect
3.5
Faraday mirror
reflecting mirror that rotates the polarization angle by the Faraday effect
3.6
intensity modulation method
method of converting the rotation of a polarization plane to light intensity and generating an
optical signal that corresponds to the current to be measured by passing light, first through a
sensing element and then through a polarization separation element, in an optical current
sensor
3.7
interferometric method
method of generating an optical signal that corresponds to the current to be measured by an
optical current sensor by converting the left-handed and right-handed circularly polarized light
that passed through the Faraday element to the same polarization, then interfering with each
other to convert the polarized light to the light intensity
3.8
maximum measurable current
maximum measurable value of the current to be measured by an optical current sensor
3.9
maximum measurable frequency
maximum measurable frequency of the current to be measured by an optical current sensor
3.10
minimum measurable frequency
minimum measurable frequency of the current to be measured by an optical current sensor
3.11
operating temperature range
range of temperatures within which an optical current sensor satisfies the defined performances
3.12
optical current sensor
...