Road vehicles — Vehicle test methods for electrical disturbances from narrowband radiated electromagnetic energy — Part 1: General principles and terminology

ISO 11451-1:2015 specifies general conditions, defines terms, gives practical guidelines, and establishes the basic principles of the vehicle tests used in the other parts of ISO 11451, for determining the immunity of passenger cars and commercial vehicles to electrical disturbances from narrowband radiated electromagnetic energy, regardless of the vehicle propulsion system (e.g. spark-ignition engine, diesel engine, electric motor). The electromagnetic disturbances considered are limited to continuous narrowband electromagnetic fields. A wide frequency range (0,01 MHz to 18 000 MHz) is allowed for the immunity testing in this and the other parts of ISO 11451.

Véhicules routiers — Méthodes d'essai d'un véhicule soumis à des perturbations électriques par rayonnement d'énergie électromagnétique en bande étroite — Partie 1: Principes généraux et terminologie

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9092 - International Standard to be revised
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INTERNATIONAL ISO
STANDARD 11451-1
Fourth edition
2015-06-01
Road vehicles — Vehicle test methods
for electrical disturbances from
narrowband radiated electromagnetic
energy —
Part 1:
General principles and terminology
Véhicules routiers — Méthodes d’essai d’un véhicule soumis
à des perturbations électriques par rayonnement d’énergie
électromagnétique en bande étroite —
Partie 1: Principes généraux et terminologie
Reference number
ISO 11451-1:2015(E)
ISO 2015
---------------------- Page: 1 ----------------------
ISO 11451-1:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

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ii © ISO 2015 – All rights reserved
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ISO 11451-1:2015(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 General aim and practical use ................................................................................................................................................................ 5

5 General test conditions .................................................................................................................................................................................. 6

5.1 General ........................................................................................................................................................................................................... 6

5.2 Test temperature ................................................................................................................................................................................... 7

5.3 Supply voltage ......... ................................................................................................................................................................................. 7

5.3.1 Vehicle Low Voltage (LV) power supply....................................................................................................... 7

5.3.2 Hybrid or electric vehicle not connected to power mains ........................................................... 7

5.3.3 Hybrid or electric vehicle in charging mode (AC or DC) ............................................................... 7

5.4 Modulation ................................................................................................................................................................................................. 7

5.5 Dwell time ................................................................................................................................................................................................... 8

5.6 Frequency step sizes .......................................................................................................................................................................... 8

5.7 Definition of test severity levels ............................................................................................................................................... 9

5.8 Disturbance application .................................................................................................................................................................. 9

6 Instrumentation .................................................................................................................................................................................................... 9

6.1 AN, AMN, and AAN ............................................................................................................................................................................... 9

6.2 Test signal quality ................................................................................................................................................................................. 9

7 Test procedure .....................................................................................................................................................................................................10

7.1 Test plan .....................................................................................................................................................................................................10

7.2 Test methods ..........................................................................................................................................................................................10

7.2.1 General...................................................................................................................................................................................10

7.2.2 Substitution .......................................................................................................................................................................10

7.2.3 Closed loop levelling ..................................................................................................................................................11

7.2.4 Vehicle immunity measurement .....................................................................................................................11

7.3 Test report ................................................................................................................................................................................................12

Annex A (normative) Function Performance Status Classification (FPSC) ................................................................13

Annex B (normative) Artificial Networks (AN), Artificial Mains Networks (AMN) and

Asymmetric Artificial Networks (AAN) ......................................................................................................................................16

Annex C (informative) Constant peak test level .....................................................................................................................................22

Bibliography .............................................................................................................................................................................................................................25

© ISO 2015 – All rights reserved iii
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ISO 11451-1:2015(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers

to Trade (TBT) see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/TC 22, Road vehicles, Subcommittee SC 32, Electrical

and electronic components and general system aspects.

This fourth edition cancels and replaces the third edition (ISO 11451-1:2005), which has been technically

revised. It also incorporates the Amendment ISO 11451-1:2005/Amd 1:2008.

ISO 11451 consists of the following parts, under the general title Road vehicles — Vehicle test methods for

electrical disturbances from narrowband radiated electromagnetic energy:
— Part 1: General principles and terminology
— Part 2: Off-vehicle radiation sources
— Part 3: On-board transmitter simulation
— Part 4: Bulk current injection (BCI)
iv © ISO 2015 – All rights reserved
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ISO 11451-1:2015(E)
Introduction

In recent years, an increasing number of electronic devices for controlling, monitoring, and displaying a

variety of functions have been introduced into vehicle designs. It is necessary to consider the electrical

and electromagnetic environment in which these devices operate.

Electrical and radio-frequency disturbances occur during the normal operation of many items of

motor vehicle equipment. They are generated over a wide frequency range with various electrical

characteristics and can be distributed to on-board electronic devices and systems by conduction,

radiation, or both. Narrowband signals generated from sources on or off the vehicle can also be coupled

into the electrical and electronic system, affecting the normal performance of electronic devices. Such

sources of narrowband electromagnetic disturbances include mobile radios and broadcast transmitters.

The characteristics of the immunity of a vehicle to radiated disturbances have to be established.

ISO 11451 provides various test methods for the evaluation of vehicle immunity characteristics (not all

methods need be used to test a vehicle).

ISO 11451 is not intended as a product specification and cannot function as one (see A.1). Therefore, no

specific values for the test severity level are given.

Annex A specifies a general method for function performance status classification (FPSC), Annex

B specifies Artificial Networks (AN), Artificial Mains Networks (AMN) and Asymmetric Artificial

Networks (AAN), while annex C explains the principle of constant peak test level. Typical severity levels

are included in an annex of each of the other parts of ISO 11451.

Protection from potential disturbances needs to be considered in a total system validation, and this can

be achieved using the various parts of ISO 11451.

NOTE Immunity measurements of complete vehicles are generally able to be carried out only by the vehicle

manufacturer, owing to, for example, high costs of absorber-lined shielded enclosures, the desire to preserve

the secrecy of prototypes or a large number of different vehicle models. ISO 11452 specifies test methods for the

analysis of component immunity, which are better suited for supplier use.
© ISO 2015 – All rights reserved v
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INTERNATIONAL STANDARD ISO 11451-1:2015(E)
Road vehicles — Vehicle test methods for electrical
disturbances from narrowband radiated electromagnetic
energy —
Part 1:
General principles and terminology
1 Scope

This part of ISO 11451 specifies general conditions, defines terms, gives practical guidelines, and

establishes the basic principles of the vehicle tests used in the other parts of ISO 11451, for determining

the immunity of passenger cars and commercial vehicles to electrical disturbances from narrowband

radiated electromagnetic energy, regardless of the vehicle propulsion system (e.g. spark-ignition engine,

diesel engine, electric motor).

The electromagnetic disturbances considered are limited to continuous narrowband electromagnetic

fields. A wide frequency range (0,01 MHz to 18 000 MHz) is allowed for the immunity testing in this and

the other parts of ISO 11451.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

CISPR 16-1-2, Specification for radio disturbance and immunity measuring apparatus and methods —

Part 1-2: Radio disturbance and immunity measuring apparatus — Ancillary equipment — Conducted

disturbances; Edition 1.2.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
absorber-lined shielded enclosure

shielded enclosure/screened room with radio frequency absorbing material on its internal ceiling and

walls

Note 1 to entry: The common practice is for the room to have a metallic floor, but absorbing material can also be

used on the floor.
3.2
amplitude modulation

process by which the amplitude of a carrier wave is varied following a specified law, resulting in an AM

signal
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ISO 11451-1:2015(E)
3.3
artificial mains network
AMN

provides a defined impedance to the EUT at radio frequencies, couples the disturbance voltage to the

measuring receiver, and decouples the test circuit from the supply mains

Note 1 to entry: There are two basic types of AMN, the V-network (V-AMN) which couples the unsymmetrical

voltages and the delta-network which couples the symmetric and the asymmetric voltages separately. The terms

line impedance stabilization network (LISN) and V-AMN are used.

Note 2 to entry: This network is inserted in the power mains of the vehicle in charging mode and provides, in a

given frequency range, a specified load impedance and which isolates the vehicle from the power mains in that

frequency range.
3.4
artificial network

network inserted in the supply lead or signal/load lead of apparatus to be tested which provides, in a

given frequency range, a specified load impedance for the measurement of disturbance voltages and

which can isolate the apparatus from the supply or signal sources/loads in that frequency range

Note 1 to entry: This network is inserted in the DC power lines of the vehicle in charging mode and provides, in

a given frequency range, a specified load impedance and which isolates the vehicle from the DC power supply in

that frequency range.
3.5
asymmetric artificial network
AAN

network used to measure (or inject) asymmetric (common mode) voltages on unshielded symmetric

signal (e.g. telecommunication) lines while rejecting the symmetric (differential mode) signal

Note 1 to entry: This network is inserted in the communication/signal lines of the vehicle in charging mode to

provide a specific load impedance and/or a decoupling (e.g. between communication/signal lines and power

mains).
3.6
bonded (ground connection and DC resistance)

grounding connection where the purpose of the bonding is to provide the lowest possible impedance

(resistance and inductance) connection between two metallic parts with a d.c. resistance which shall

not exceed 2,5 mΩ

Note 1 to entry: A low current (≤100 mA) 4-wire milliohm meter is recommended for this measurement.

3.7
bulk current
total amount of common mode current in a harness
3.8
compression point
input signal level at which the measurement system becomes non-linear

Note 1 to entry: When the measurement system is non-linear, the output value will deviate from the value given

by an ideal linear system.
3.9
coupling
means or device for transferring power between systems
[SOURCE: IEC 60050-726]
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ISO 11451-1:2015(E)
3.10
current injection probe

device for injecting current in a conductor without interrupting the conductor and without introducing

significant impedance into the associated circuits
3.11
current (measuring) probe

device for measuring the current in a conductor without interrupting the conductor and without

introducing significant impedance into the associated circuits
[SOURCE: IEC 60050-161]
3.12
degradation (of performance)

undesired departure in the operational performance of any device, equipment, or system from its

intended performance

Note 1 to entry: The term “degradation” can apply to temporary or permanent failure.

[SOURCE: IEC 60050-161]
3.13
dual directional coupler

four-port device consisting of two transmission lines coupled together in such a manner that a single

travelling wave in any one transmission line will induce a single travelling wave in the other, the direction

of propagation of the latter wave being dependent upon that of the former
[SOURCE: IEC 60050-726]
3.14
electromagnetic compatibility
EMC

ability of equipment or system to function satisfactorily in its electromagnetic environment without

introducing intolerable electromagnetic disturbance to anything in that environment

[SOURCE: IEC 60050-161]
3.15
electromagnetic disturbance

any electromagnetic phenomenon which can degrade the performance of a device, equipment, or system

or adversely affect living or inert matter

EXAMPLE An electromagnetic disturbance can be an electromagnetic noise, an unwanted signal, or a change

in the propagation medium itself.
[SOURCE: IEC 60050-161]
3.16
electromagnetic interference
EMI

degradation of the performance of equipment, transmission channel, or system caused by electromagnetic

disturbance

Note 1 to entry: The English words “interference” and “disturbance” are often used indiscriminately.

[SOURCE: IEC 60050-161]
© ISO 2015 – All rights reserved 3
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ISO 11451-1:2015(E)
3.17
(electromagnetic) susceptibility

inability of a device, equipment, or system to perform without degradation in the presence of an

electromagnetic disturbance
Note 1 to entry: Susceptibility is the lack of immunity.
[SOURCE: IEC 60050-161]
3.18
forward power
power supplied by the output of an amplifier or generator
3.19
ground (reference) plane
flat conductive surface whose potential is used as a common reference
[SOURCE: IEC 60050-161]
3.20
immunity (to a disturbance)

ability of a device, equipment, or system to perform without degradation in the presence of an

electromagnetic disturbance
[SOURCE: IEC 60050-161]
3.21
immunity level

maximum level of a given electromagnetic disturbance incident on a particular device, equipment, or

system for which it remains capable of operating at a required degree of performance

[SOURCE: IEC 60050-161]
3.22
narrowband emission

emission which has a bandwidth less than that of a particular measuring apparatus or receiver

[SOURCE: IEC 60050-161]
3.23
polarization (of wave or field vector)

property of sinusoidal electromagnetic wave or field vector defined at a fixed point in space by the

direction of the electric field strength vector or of any specified field vector, when this direction varies

with time

Note 1 to entry: The property can be characterized by the locus described by the extremity of the considered field

vector.
[SOURCE: IEC 60050-726]
3.24
portable transmitter
hand-held radio frequency communication device

Note 1 to entry: A portable transmitter could be a commercial device (e.g. cellular phone) or a simulated one.

3.25
power mains

general purpose alternating current (AC) or direct current (DC) electric power supply

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ISO 11451-1:2015(E)
3.26
pulse modulation

process by which the amplitude of a carrier wave is varied following a specified law, resulting in a PM

signal
3.27
(electromagnetic) radiation

phenomenon by which energy in the form of electromagnetic waves emanates from a source into space;

energy transferred through space in the form of electromagnetic waves

Note 1 to entry: By extension, the term “electromagnetic radiation” sometimes also covers induction phenomena.

[SOURCE: IEC 60050-161]
3.28
reflected power
power reflected by the load due to impedance mismatch between RF-source and load
3.29
shielded enclosure
screened room

mesh or sheet metallic housing designed expressly for the purpose of separating electromagnetically

the internal and external environment
[SOURCE: IEC 60050-161]
3.30
voltage standing wave ratio
VSWR

ratio along a transmission line of a maximum to an adjacent minimum magnitude of a particular field

component of a standing wave
()1+r
VSWR =
()1−r
where r is the absolute value of the coefficient of reflection
[SOURCE: IEC 60050-726]
3.31
transmission line system
TLS

field-generating device that works in a similar way to a TEM (transverse electromagnetic) wave generator

EXAMPLE Stripline, TEM cell, parallel plate.
4 General aim and practical use

The test methods, procedures, test instrumentation, and levels specified in ISO 11451 are intended

to facilitate vehicle specification for electrical disturbances by narrowband radiated electromagnetic

energy. A basis is provided for mutual agreement between vehicle manufacturers and component

suppliers intended to assist rather than restrict.

Certain devices are particularly susceptible to some characteristics of electromagnetic disturbance,

such as frequency, severity level, type of coupling, or modulation.

Electronic devices are sometimes more susceptible to modulated, as opposed to unmodulated, radio-

frequency (RF) signals. The reason is that high-frequency disturbances can be demodulated by

semiconductors. In the case of unmodulated signals, this leads to a continuous shift of, for example, a

voltage; in the case of amplitude-modulated signals, the resulting low-frequency fluctuations can be

© ISO 2015 – All rights reserved 5
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ISO 11451-1:2015(E)

interpreted as intentional signals (e.g. speed information) and therefore disturb the function of the

device under test (DUT) more severely.

A single standard test may not reveal all the needed information about the DUT. It is thus necessary for

users of ISO 11451 to anticipate the appropriate test conditions, select applicable parts of ISO 11451, and

define function performance objectives. The main characteristics of each test method in ISO 11451-2 to

ISO 11451-4 are presented in Table 1.
Table 1 — Main characteristics of test methods in ISO 11451
Test severity
Applicable fre-
Part of ISO 11451 Coupling to parameter and Provisions
quency range
unit
ISO 11451-2
Components and Absorber-lined shielded
10 kHz to 18 GHz Electric field (V/m)
Off-vehicle radiation
wiring harness enclosure required
sources
ISO 11451-3
Absorber-lined shielded
Components and
1,8 MHz to 5,85 GHz Power (W) enclosure recom-
On-board transmitter
wiring harness
mended
simulation
ISO 11451-4
Shielded enclosure rec-
1 MHz to 400 MHz Wiring harness Current (mA)
Bulk current injection
ommended
(BCI)
5 General test conditions
5.1 General

Unless otherwise specified, the following test conditions are common to all parts of ISO 11451:

— test temperature;
— supply voltage;
— modulation;
— dwell time;
— frequency step sizes;
— definition of test severity level;
— test signal quality.

NOTE The use of the same parameters as those used for the component test methods given in the corresponding

parts of ISO 11451 will achieve better correlation.

Unless otherwise specified, the variables used shall have the following tolerances:

— ±10 % for durations and distances;
— ±10 % for resistances and impedances;
— and the following magnitude accuracy:
— ±1 dB for power meter including power sensor;
— ±3 dB for field probe.
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ISO 11451-1:2015(E)
5.2 Test temperature

Heat is generated in the test facility when the vehicle is operated during the performance of the test.

Sufficient cooling shall be provided to ensure that the engine does not overheat.

The ambient temperature during the test should be (23 ± 5) °C.
5.3 Supply voltage
5.3.1 Vehicle Low Voltage (LV) power supply

LV is used for d.c. operating voltages below 60 V (e.g. 12 V, 24 V, 48 V). For tests that require the vehicle

engine to be running, the electrical charging system shall be functional. For tests where the vehicle

engine is not required to be running, unless other values are specified in the test plan, the battery

voltage shall be maintained above 12 V for 12 V systems and above 24 V for 24 V systems.

5.3.2 Hybrid or electric vehicle not connected to power mains

HV is used for operating voltages from 60 V to 1000 V d.c. The minimum high voltage value shall be

defined in the test plan.
5.3.3 Hybrid or electric vehicle in charging mode (AC or DC)
The DC power supply voltage during the test shall be nominal ±10 %.

The AC power supply voltage during the test shall be nominal −15 % +10 %. The rated value of the

frequency shall be nominal ±1 %.
5.4 Modulation

The characteristics of the DUT determine the type and frequency of modulation to be used. If no values

or specific modulation techniques are agreed between the users of ISO 11451, the following shall be

used:
a) unmodulated sine wave (CW). See Figure 1 a);

b) sine wave amplitude modulated (AM) by 1 kHz sine wave at 80 % (modulation index m = 0,8) [see

Annex C and Figure 1 b)];

c) sine wave pulse modulated type 1 (PM, similar to GSM), with ton = 577 µs and period = 4 600 µs [see

Figure 1 c)];

d) sine wave pulse modulated type 2 (PM, similar to radar), with ton = 3 µs and period = 3333 µs; [see

Figure 1 d)].
© ISO 2015 – All rights reserved 7
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ISO 11451-1:2015(E)

In practice, PM modulation shall not be obtained using either the blanking of the amplifier or a 100 %

(modulation index m = 1) AM modulation type.
a) CW signal b) AM signal
c) PM type 1 signal d) PM type 2 signal
Key
f frequency
Figure 1 — Modulation
The following modulations should be used for all applicable parts of ISO 11451:
— CW: 0,01 MHz to 18 GHz;
— AM: 0,01 MHz to 800 MHz;
— PM type 1: 800 MHz to 1,2 GHz; 1,4 GHz to 2,7 GHz;
— PM type 2: 1,2 GHz to 1,4 GHz and 2,7 GHz to 18 GHz.
5.5 Dwell time

At each frequency, the vehicle shall be exposed to the test level for a time equal to the response time

of the vehicle system. If a dwell time is not specified in the test plan, or system response time is not

specified, then the dwell time shall be a minimum of 1 s.
5.6 Frequency step sizes

All tests in ISO 11451 shall be conducted with frequency step sizes (logarithmic or linear) not greater

than those specified in Table 2. The step sizes agreed upon by the users of this part of ISO 11451 shall be

documented in the test report.
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ISO 11451-1:2015(E)
Table 2 — Maximum frequency step sizes
Frequency band Linear steps Logarithmic steps
10 kHz to 100 kHz 10 kHz 10 %
>100 kHz to 1 MHz 100 kHz 10 %
>1 MHz to 10 MHz 1 MHz 10 %
>10 MHz to 200 MHz 5 MHz 5 %
>200 MHz to 400 MHz 10 MHz 5 %
>400 MHz to 1 GHz 20 MHz 2 %
>1 GHz to 18 GHz 40 MHz 2 %

If it appears that the susceptibility thresholds of the DUT are very near to the chosen test level, these

frequency step sizes should be reduced in the frequency range concerned in order to find the minimum

susceptibility thresholds.
5.7 Definition of test severity levels

The user should specify the test severity level or levels over the frequency range. The concept of FPSC

is detailed in Annex A. For both the substitution and closed loop levelling methods, and for tests with

unmodulated and amplitude-modulated signals, the test severity levels of ISO 11451 (electric field,

current, voltage, or power) are expressed in terms of the equivalent root-mean-square level value of the

unmodulated wave.

Both these methods use a constant peak test level for tests with unmodulated and amplitude-modulated

signals. The relationship between the mean power for the amplitude-modulated signal and the mean

power for
...

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