ISO 21498-2:2021

Electrically propelled road vehicles — Electrical specifications and tests for voltage class B systems and components — Part 2: Electrical tests for components

This document applies to voltage class B electric propulsion systems and connected auxiliary electric systems of electrically propelled road vehicles. It applies to electric circuits and components in these systems. This document focuses on the characteristics at the DC voltage class B terminals of these components as specified in ISO 21498-1. It describes testing methods, test conditions and test requirements for components exposed to electrical behaviour caused by operation of electric loads and power sources. This document does not cover electrical safety (see ISO 6469, ISO 17409).

Véhicules à propulsion electrique — Spécifications et essais electriques pour les systèmes et composants de classe B — Partie 2: Composants et essais electriques

General Information

• Status: Published
• Publication Date: 22-Mar-2021
• ICS: 43.120 - Electric road vehicles
• Technical Committee: ISO/TC 22/SC 37 - Electrically propelled vehicles
• Drafting Committee: ISO/TC 22/SC 37 - Electrically propelled vehicles
• Current Stage: 9092 - International Standard to be revised
• Completion Date: 18-Jan-2022

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21498-2
First edition
2021-03
Electrically propelled road vehicles —
Electrical specifications and tests
for voltage class B systems and
components —
Part 2:
Electrical tests for components
Véhicules à propulsion electrique — Spécifications et essais
electriques pour les systèmes et composants de classe B —
Partie 2: Composants et essais electriques
Reference number
ISO 21498-2:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 21498-2:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 21498-2:2021(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 General assumptions for voltage class B components . 3
6 Tests and requirements . 5
6.1 Test parameters and general test requirements . 5
6.1.1 Purpose . 5
6.1.2 Test setup . 5
6.1.3 Voltages . 5
6.1.4 Powers . 6
6.1.5 Temperatures . 6
6.1.6 Times and durations . 6
6.1.7 Standard tolerances . 7
6.1.8 Ambient conditions . 7
6.1.9 Wiring harness . 8
6.1.10 Load conditions. 8
6.1.11 Sampling rates and measured value resolutions . 8
6.1.12 Parameter monitoring . . 8
6.1.13 Interface description . 8
6.1.14 Documentation . 8
6.2 DC supply voltage variation within operational range . 9
6.2.1 Purpose . 9
6.2.2 Test setup . 9
6.2.3 Test procedure . 9
6.2.4 Requirements .10
6.3 Generated voltage slope .11
6.3.1 Purpose .11
6.3.2 Test setup .11
6.3.3 Test procedure .12
6.3.4 Requirements .14
6.4 Immunity to voltage slope .14
6.4.1 Purpose .14
6.4.2 Test setup .14
6.4.3 Test procedure .15
6.4.4 Requirements .16
6.5 Generated voltage ripple .16
6.5.1 Purpose .16
6.5.2 Test setup .16
6.5.3 Test procedure .17
6.5.4 Requirements .19
6.6 Immunity to voltage ripple .20
6.6.1 Purpose .20
6.6.2 Test setup .20
6.6.3 Test procedure .21
6.6.4 Requirements .22
6.7 Overvoltage .22
6.7.1 Purpose .22
6.7.2 Test setup .22
6.7.3 Test procedure .23
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ISO 21498-2:2021(E)

6.7.4 Requirements .24
6.8 Undervoltage .24
6.8.1 Purpose .24
6.8.2 Test setup .24
6.8.3 Test procedure .25
6.8.4 Requirements .26
6.9 Voltage offset .26
6.9.1 Purpose .26
6.9.2 Test setup .27
6.9.3 Test procedure .28
6.9.4 Requirements .29
6.10 Generated load dump voltage .30
6.10.1 Purpose .30
6.10.2 Test setup .30
6.10.3 Test procedure .30
6.10.4 Requirements .31
6.11 Immunity to load dump voltage .32
6.11.1 Purpose .32
6.11.2 Test setup .32
6.11.3 Test procedure .32
6.11.4 Requirements .34
Annex A (informative) Test overview .35
Annex B (informative) Testing at different temperatures .36
Annex C (informative) Example values .37
Annex D (normative) Artificial network .40
Annex E (informative) Example for the setup of generated voltage ripple measurement .44
Bibliography .48
iv © ISO 2021 – All rights reserved

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ISO 21498-2:2021(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 of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 37,
Electrically propelled vehicles.
A list of all parts in the ISO 21498 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2021 – All rights reserved v

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ISO 21498-2:2021(E)

Introduction
The requirements for voltage class B electric circuits that are used for electric power transfer for
the propulsion of electric road vehicles and their characteristics are significantly different to those
of voltage class A electric circuits. Moreover, the range of voltage class B is too wide to be used for a
component design regarding to voltage.
The ISO 21498 series divides voltage class B in a set of voltage sub-classes to enable a component design
for each voltage sub-class regarding to voltage. It provides appropriate descriptions and definitions for
requirements and characteristics of voltage class B systems for electrically propelled vehicles.
The voltage sub-class itself and the component characteristics have a large cost impact on the component
design and on the overall design of the electric system. Additionally, a high variety of different voltage
sub-classes and operating conditions impedes the use of an existing component in different vehicle
models. The standardisation of voltage sub-classes and characteristics and the reduction of varieties
will enable the reduction of component and system costs. This allows the decoupling of the system or
component designs of a voltage class B electric circuit from the design of the electric energy source.
Finally, the exchange of components from different suppliers for different customers is facilitated.
ISO 21498-1 provides definitions of and for voltage sub-classes and characteristics for rechargeable
energy storage systems (RESS) and electric propulsion systems. It defines specific values for these
sub-classes based on maximum working voltage. Voltage sub-classes listed in ISO 21498-1 are used for
voltage class B systems of all kinds of current or future electrically propelled road vehicles.
This document provides electrical tests for electric and electronic components at voltage class B used
for electrically propelled road vehicles. All relevant characteristics are covered considering usual
driving scenarios as well as deviations from normal operation. The descriptions are generalized and
include purpose, setup, procedure and requirements for the tests.
The specifications in this document are not intended to restrict the development of component
performance or technology. The given definition of sub-classes does not exclude the use of other
maximum operating voltages for an individual system design.
vi © ISO 2021 – All rights reserved

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INTERNATIONAL STANDARD ISO 21498-2:2021(E)
Electrically propelled road vehicles — Electrical
specifications and tests for voltage class B systems and
components —
Part 2:
Electrical tests for components
1 Scope
This document applies to voltage class B electric propulsion systems and connected auxiliary electric
systems of electrically propelled road vehicles. It applies to electric circuits and components in these
systems.
This document focuses on the characteristics at the DC voltage class B terminals of these components
as specified in ISO 21498-1. It describes testing methods, test conditions and test requirements for
components exposed to electrical behaviour caused by operation of electric loads and power sources.
This document does not cover electrical safety (see ISO 6469, ISO 17409).
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 cited edition applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/TR 8713, Electrically propelled road vehicles — Vocabulary
ISO 21498-1, Electrically propelled road vehicles – Electrical specifications and tests for voltage class B
systems and components − Part 1: Voltage sub-classes and characteristics
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TR 8713 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
component operating status
general functional behaviour of components which depend directly on the voltage in voltage class B
(3.13) electric circuits (3.3)
[SOURCE: ISO 21498-1:2021, 3.1]
3.2
customer
party that is interested in using voltage class B (3.13) components or systems
[SOURCE: ISO 21498-1:2021, 3.2]
© ISO 2021 – All rights reserved 1

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ISO 21498-2:2021(E)

3.3
electric circuit
entire set of interconnected electric/electronic parts through which electrical current is designed to
flow under normal operating conditions
[SOURCE: ISO 21498-1:2021, 3.3]
3.4
lower voltage limit
minimum voltage of a voltage class B (3.13) sub-class
3.5
maximum working voltage
highest value of AC voltage (rms) or of DC voltage that can occur under any normal operating conditions
according to the customer's (3.2) specifications, disregarding transients (3.10) and ripple (3.8)
[SOURCE: ISO 21498-1:2021, 3.5]
3.6
power network
all components within voltage class B (3.13) DC network including their connections
[SOURCE: ISO 21498-1:2021, 3.6]
3.7
rechargeable energy storage system
RESS
rechargeable system that stores energy for delivery of electric energy for the electric drive
EXAMPLE Batteries, capacitors, flywheel.
[SOURCE: ISO 21498-1:2021, 3.7]
3.8
ripple
set of unwanted periodic deviations with respect to the average value of the measured or supplied
quantity, occurring at frequencies which can be related to that of components within a system
[SOURCE: ISO 21498-1:2021, 3.8]
3.9
supplier
party that provides voltage class B (3.13) components or systems
[SOURCE: ISO 21498-1:2021, 3.9]
3.10
transient
phenomenon or quantity which varies between two consecutive steady states during a short time
interval compared to the time-scale of interest
[SOURCE: ISO 21498-1:2021, 3.10]
3.11
upper voltage limit
maximum voltage of a voltage class B (3.13) sub-class
Note 1 to entry: Maximum working voltages (3.5) within a voltage sub-class (3.15) are less than or equal to the
upper voltage limit.
2 © ISO 2021 – All rights reserved

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ISO 21498-2:2021(E)

3.12
voltage class A
classification of an electric component or circuit with a maximum working voltage (3.5) of ≤30 V AC
(rms) or ≤60 V DC respectively
[SOURCE: ISO 21498-1:2021, 3.12]
3.13
voltage class B
classification of an electric component or circuit with a maximum working voltage (3.5) of (> 30 and
≤ 1 000) V AC (rms) or (> 60 and ≤ 1 500) V DC respectively
[SOURCE: ISO 21498-1:2021, 3.13]
3.14
voltage range
general term covering voltage sub-class (3.15), working voltages (3.16) and deviations from working
voltages
[SOURCE: ISO 21498-1:2021, 3.14]
3.15
voltage sub-class
classification of an electric component or circuit with a DC voltage within the voltage class B (3.13)
3.16
working voltage
AC voltage (rms) or DC voltage that can occur in an electric system under normal operating conditions
according to the customer's (3.2) specifications, disregarding transients (3.10) and ripple (3.8)
4 Abbreviated terms
DUT device under test
EV electrically propelled road vehicle
HV high voltage
OS operating status
LV low voltage
5 General assumptions for voltage class B components
General assumptions and definitions for voltage class B systems shall be as in ISO 21498-1.
Figure 1 shows a generalized view on a voltage class B component. Some of the connections shown
may not be available for all voltage class B components. All voltage profiles or voltage values in this
document refer to the voltage between the “HV+” and “HV-” terminals of a voltage class B component, if
not otherwise stated.
Due to the differences between different voltage class B components, Table A.1 gives an overview on
how the different tests, which are described in this document, are applicable. Not all tests are reasonable
for all voltage class B components.
A voltage class B component may have multiple interfaces for each type of voltage (voltage class B DC,
voltage class B AC, voltage class A, according to Figure 1). For example, a DC/DC converter may interface
to two voltage class B electric circuits.
© ISO 2021 – All rights reserved 3

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ISO 21498-2:2021(E)

A voltage class B component may have multiple voltage class B DC terminals, which can be galvanically
separated. The tests described in this document shall be fulfilled for each of these terminals.
Key
1 voltage class B connection: HV+ 8 connection to further voltage class B component
(e.g. AC or DC power network)
a
2 voltage class B connection: HV- DUT.
b
3 voltage class A power Voltage class B circuit.
c
4 I/O and bus signals Voltage class A circuit.
d
5 terminal with direct connection to voltage class A Galvanic separation between voltage class A and
ground reference voltage class B.
e
6 ground reference Voltage class B terminals under test.
7 connection to further voltage class B component
(e.g. electric motor)
Figure 1 — Generalized voltage class B component diagram
For the purpose of testing, Figure 2 summarizes the voltage operating ranges and OS of a voltage class B
component at its voltage class B DC voltage terminals. The overvoltage limit, the upper voltage limit and
the lower voltage limit are properties of the component.
Each voltage class B component shall have a voltage range in which it can be operated with its specified
performance (unlimited operating capability). All designated functions, including short-time overload
operations, shall be available. Within this voltage range, the component operates in OS1.
Above a maximum voltage, a component may reduce its performance as specified. This specified voltage
is called the maximum unlimited operating voltage (U ). The component shall provide its
max_unlimited_op
upper limited operating capability until the upper voltage limit (U ) is reached. In this case, the
upper_limit
component operates in OS2.
Above the upper voltage limit (U ) the component may derate or cut-off its performance for self-
upper_limit
protection. The component shall withstand this overvoltage until the overvoltage limit (U ) is
over_limit
reached. In this case, the component operates in OS3 or OS4.
A component shall perform in OS1 until the supply voltage drops to the minimum unlimited operating
voltage (U ). Between the minimum unlimited operating voltage (U ) and the
min_unlimited_op min_unlimited_op
lower voltage limit (U ), the component may reduce its performance as specified. In this case,
lower_limit
the component operates in OS2.
If the supply voltage is below the U , the component may derate or cut-off its performance. In
lower_limit
this case, the component operates in OS3 or OS4.
4 © ISO 2021 – All rights reserved
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 21498-2
ISO/TC 22/SC 37
Electrically propelled road vehicles —
Secretariat: DIN
Electrical specifications and tests
Voting begins on:
2020-12-23 for voltage class B systems and
components —
Voting terminates on:
2021-02-17
Part 2:
Electrical tests for components
Véhicules à propulsion electrique — Spécifications et essais
electriques pour les systèmes et composants de classe B —
Partie 2: Composants et essais electriques
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 21498-2:2020(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2020

---------------------- Page: 1 ----------------------
ISO/FDIS 21498-2:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 21498-2:2020(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 General assumptions for voltage class B components . 3
6 Tests and requirements . 5
6.1 Test parameters and general test requirements . 5
6.1.1 Purpose . 5
6.1.2 Test setup . 5
6.1.3 Voltages . 5
6.1.4 Powers . 6
6.1.5 Temperatures . 6
6.1.6 Times and durations . 6
6.1.7 Standard tolerances . 7
6.1.8 Ambient conditions . 7
6.1.9 Wiring harness . 8
6.1.10 Load conditions. 8
6.1.11 Sampling rates and measured value resolutions . 8
6.1.12 Parameter monitoring . . 8
6.1.13 Interface description . 8
6.1.14 Documentation . 8
6.2 DC supply voltage variation within operational range . 8
6.2.1 Purpose . 8
6.2.2 Test setup . 9
6.2.3 Test procedure . 9
6.2.4 Requirements .10
6.3 Generated voltage slope .11
6.3.1 Purpose .11
6.3.2 Test setup .11
6.3.3 Test procedure .12
6.3.4 Requirements .14
6.4 Immunity to voltage slope .14
6.4.1 Purpose .14
6.4.2 Test setup .14
6.4.3 Test procedure .15
6.4.4 Requirements .16
6.5 Generated voltage ripple .16
6.5.1 Purpose .16
6.5.2 Test setup .16
6.5.3 Test procedure .17
6.5.4 Requirements .19
6.6 Immunity to voltage ripple .20
6.6.1 Purpose .20
6.6.2 Test setup .20
6.6.3 Test procedure .21
6.6.4 Requirements .22
6.7 Overvoltage .22
6.7.1 Purpose .22
6.7.2 Test setup .22
6.7.3 Test procedure .23
© ISO 2020 – All rights reserved iii

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ISO/FDIS 21498-2:2020(E)

6.7.4 Requirements .24
6.8 Undervoltage .24
6.8.1 Purpose .24
6.8.2 Test setup .24
6.8.3 Test procedure .25
6.8.4 Requirements .26
6.9 Voltage offset .26
6.9.1 Purpose .26
6.9.2 Test setup .27
6.9.3 Test procedure .28
6.9.4 Requirements .30
6.10 Generated load dump voltage .30
6.10.1 Purpose .30
6.10.2 Test setup .30
6.10.3 Test procedure .30
6.10.4 Requirements .31
6.11 Immunity to load dump voltage .32
6.11.1 Purpose .32
6.11.2 Test setup .32
6.11.3 Test procedure .32
6.11.4 Requirements .34
Annex A (informative) Test overview .35
Annex B (informative) Testing at different temperatures .36
Annex C (informative) Example values .37
Annex D (normative) Artificial network .40
Annex E (informative) Example for the setup of generated voltage ripple measurement .44
Bibliography .48
iv © ISO 2020 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 21498-2:2020(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 of the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the World Trade Organization (WTO)
principles in the Technical Barriers to Trade (TBT), see www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 37,
Electrically propelled vehicles.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2020 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO/FDIS 21498-2:2020(E)

Introduction
The requirements for voltage class B electric circuits that are used for electric power transfer for
the propulsion of electric road vehicles and their characteristics are significantly different to those
of voltage class A electric circuits. Moreover, the range of voltage class B is too wide to be used for a
component design regarding to voltage.
The ISO 21498 series divides voltage class B in a set of voltage sub-classes to enable a component design
for each voltage sub-class regarding to voltage. It provides appropriate descriptions and definitions for
requirements and characteristics of voltage class B systems for electrically propelled vehicles.
The voltage sub-class itself and the component characteristics have a large cost impact on the component
design and on the overall design of the electric system. Additionally, a high variety of different voltage
sub-classes and operating conditions impedes the use of an existing component in different vehicle
models. The standardisation of voltage sub-classes and characteristics and the reduction of varieties
will enable the reduction of component and system costs. This allows the decoupling of the system or
component designs of a voltage class B electric circuit from the design of the electric energy source.
Finally, the exchange of components from different suppliers for different customers is facilitated.
ISO 21498-1 provides definitions of and for voltage sub-classes and characteristics for rechargeable
energy storage systems (RESS) and electric propulsion systems. It defines specific values for these
sub-classes based on maximum working voltage. Voltage sub-classes listed in ISO 21498-1 are used for
voltage class B systems of all kinds of current or future electrically propelled road vehicles.
This document provides electrical tests for electric and electronic components at voltage class B used
for electrically propelled road vehicles. All relevant characteristics are covered considering usual
driving scenarios as well as deviations from normal operation. The descriptions are generalized and
include purpose, setup, procedure and requirements for the tests.
The specifications in this document are not intended to restrict the development of component
performance or technology. The given definition of sub-classes does not exclude the use of other
maximum operating voltages for an individual system design.
vi © ISO 2020 – All rights reserved

---------------------- Page: 6 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 21498-2:2020(E)
Electrically propelled road vehicles — Electrical
specifications and tests for voltage class B systems and
components —
Part 2:
Electrical tests for components
1 Scope
This document applies to voltage class B electric propulsion systems and connected auxiliary electric
systems of electrically propelled road vehicles. It applies to electric circuits and components in these
systems.
This document focuses on the characteristics at the DC voltage class B terminals of these components
as specified in ISO 21498-1. It describes testing methods, test conditions and test requirements for
components exposed to electrical behaviour caused by operation of electric loads and power sources.
This document does not cover electrical safety (see ISO 6469, ISO 17409).
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 cited edition applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/TR 8713, Electrically propelled road vehicles — Vocabulary
ISO 21498-1, Electrically propelled road vehicles – Electrical specifications and tests for voltage class B
systems and components − Part 1: Voltage sub-classes and characteristics
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TR 8713 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
component operating status
general functional behaviour of components which depend directly on the voltage in voltage class B
(3.13) electric circuits (3.3)
[SOURCE: ISO 21498-1:2021, 3.1]
3.2
customer
party that is interested in using voltage class B (3.13) components or systems
[SOURCE: ISO 21498-1:2021, 3.2]
© ISO 2020 – All rights reserved 1

---------------------- Page: 7 ----------------------
ISO/FDIS 21498-2:2020(E)

3.3
electric circuit
entire set of interconnected electric/electronic parts through which electrical current is designed to
flow under normal operating conditions
[SOURCE: ISO 21498-1:2021, 3.3]
3.4
lower voltage limit
minimum voltage of a voltage class B (3.13) sub-class
3.5
maximum working voltage
highest value of AC voltage (rms) or of DC voltage that can occur under any normal operating conditions
according to the customer's (3.2) specifications, disregarding transients (3.10) and ripple (3.8)
[SOURCE: ISO 21498-1:2021, 3.5]
3.6
power network
all components within voltage class B (3.13) DC network including their connections
[SOURCE: ISO 21498-1:2021, 3.6]
3.7
rechargeable energy storage system
RESS
rechargeable system that stores energy for delivery of electric energy for the electric drive
EXAMPLE Batteries, capacitors, flywheel.
[SOURCE: ISO 21498-1:2021, 3.7]
3.8
ripple
set of unwanted periodic deviations with respect to the average value of the measured or supplied
quantity, occurring at frequencies which can be related to that of components within a system
[SOURCE: ISO 21498-1:2021, 3.8]
3.9
supplier
party that provides voltage class B (3.13) components or systems
[SOURCE: ISO 21498-1:2021, 3.9]
3.10
transient
phenomenon or quantity which varies between two consecutive steady states during a short time
interval compared to the time-scale of interest
[SOURCE: ISO 21498-1:2021, 3.10]
3.11
upper voltage limit
maximum voltage of a voltage class B (3.13) sub-class
Note 1 to entry: Maximum working voltages (3.5) within a voltage sub-class (3.15) are less than or equal to the
upper voltage limit.
2 © ISO 2020 – All rights reserved

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ISO/FDIS 21498-2:2020(E)

3.12
voltage class A
classification of an electric component or circuit with a maximum working voltage (3.5) of ≤30 V AC
(rms) or ≤60 V DC respectively
[SOURCE: ISO 21498-1:2021, 3.12]
3.13
voltage class B
classification of an electric component or circuit with a maximum working voltage (3.5) of (> 30 and
≤ 1 000) V AC (rms) or (> 60 and ≤ 1 500) V DC respectively
[SOURCE: ISO 21498-1:2021, 3.13]
3.14
voltage range
general term covering voltage sub-class (3.15), working voltages (3.16) and deviations from working
voltages
[SOURCE: ISO 21498-1:2021, 3.14]
3.15
voltage sub-class
classification of an electric component or circuit with a DC voltage within the voltage class B (3.13)
3.16
working voltage
AC voltage (rms) or DC voltage that can occur in an electric system under normal operating conditions
according to the customer's (3.2) specifications, disregarding transients (3.10) and ripple (3.8)
4 Abbreviated terms
DUT device under test
EV electrically propelled road vehicle
HV high voltage
OS operating status
LV low voltage
5 General assumptions for voltage class B components
General assumptions and definitions for voltage class B systems shall be as in ISO 21498-1.
Figure 1 shows a generalized view on a voltage class B component. Some of the connections shown
may not be available for all voltage class B components. All voltage profiles or voltage values in this
document refer to the voltage between the “HV+” and “HV-” terminals of a voltage class B component, if
not otherwise stated.
Due to the differences between different voltage class B components, Table A.1 gives an overview on
how the different tests, which are described in this document, are applicable. Not all tests are reasonable
for all voltage class B components.
A voltage class B component may have multiple interfaces for each type of voltage (voltage class B DC,
voltage class B AC, voltage class A, according to Figure 1). For example, a DC/DC converter may interface
to two voltage class B electric circuits.
© ISO 2020 – All rights reserved 3

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ISO/FDIS 21498-2:2020(E)

A voltage class B component may have multiple voltage class B DC terminals, which can be galvanically
separated. The tests described in this document shall be fulfilled for each of these terminals.
Key
1 voltage class B connection: HV+ 8 connection to further voltage class B component
(e.g. AC or DC power network)
a
2 voltage class B connection: HV- DUT.
b
3 voltage class A power Voltage class B circuit.
c
4 I/O and bus signals Voltage class A circuit.
d
5 terminal with direct connection to voltage class A Galvanic separation between voltage class A and
ground reference voltage class B.
e
6 ground reference Voltage class B terminals under test.
7 connection to further voltage class B component
(e.g. electric motor)
Figure 1 — Generalized voltage class B component diagram
For the purpose of testing, Figure 2 summarizes the voltage operating ranges and OS of a voltage class B
component at its voltage class B DC voltage terminals. The overvoltage limit, the upper voltage limit and
the lower voltage limit are properties of the component.
Each voltage class B component shall have a voltage range in which it can be operated with its specified
performance (unlimited operating capability). All designated functions, including short-time overload
operations, shall be available. Within this voltage range, the component operates in OS1.
Above a maximum voltage, a component may reduce its performance as specified. This maximum
voltage is called the maximum unlimited operating voltage (U ). The component shall
max_unlimited_op
provide its upper limited operating capability until the upper voltage limit (U ) is reached. In
upper_limit
this case, the component operates in OS2.
Above the upper voltage limit (U ) the component may derate or cut-off its performance for self-
upper_limit
protection. The component shall withstand this overvoltage until the overvoltage limit (U ) is
over_limit
reached. In this case, the component operates in OS3 or OS4.
A component shall perform i
...