ISO/DIS 21498-1

DRAFT INTERNATIONAL STANDARD
ISO/DIS 21498-1
ISO/TC 22/SC 37 Secretariat: DIN
Voting begins on: Voting terminates on:
2020-01-29 2020-04-22
Electrically propelled road vehicles — Electrical
specifications and tests for voltage class B systems and
components —
Part 1:
Voltage sub-classes and characteristics
ICS: 43.120
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ISO/DIS 21498-1:2020(E)
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ISO/DIS 21498-1:2020(E)
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Foreword ........................................................................................................................................................................................................................................iv

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

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

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

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

4 Abbreviated terms .............................................................................................................................................................................................. 3

5 General assumptions for the voltage class B system ....................................................................................................... 3

6 Voltage sub-classes ............................................................................................................................................................................................. 3

7 Characteristics of voltage sub-classes ............................................................................................................................................ 4

7.1 General ........................................................................................................................................................................................................... 4

7.2 Component operating status ....................................................................................................................................................... 4

7.3 Voltage operating ranges ................................................................................................................................................................ 5

7.4 Undervoltage and overvoltage .................................................................................................................................................. 5

7.4.1 General...................................................................................................................................................................................... 5

7.4.2 Overvoltage ...................................................................... ..................................................................................................... 6

7.4.3 Undervoltage ....................................................................................................................................................................... 6

7.5 Allocation of voltage ranges and operating status – Overview ..................................................................... 6

7.6 Voltage transients and ripple...................................................................................................................................................... 8

7.6.1 General...................................................................................................................................................................................... 8

7.6.2 Voltage slope ...................................................................... .................................................................................................. 8

7.6.3 Load dump ............................................................................................................................................................................ 9

7.6.4 Voltage ripple ...................................................................................................................................................................... 9

Annex A (informative) Example for voltage ranges per voltage sub-class .................................................................10

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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

This standard 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. It 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.

Part 1 of this standard 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 this document

are used for voltage class B systems of all kinds of current or future electrically propelled road vehicles.

Part 2 of this standard 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

The specifications in this standard 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

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

This document provides specifications of voltage sub-classes related to DC electric circuits. It also

provides specifications of characteristics which are relevant for design and operation of systems and

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.

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:

general functional behaviour of components which depend directly on the voltage in voltage class B

entire set of interconnected electric/electronic parts through which electrical current is designed to

minimum voltage of a voltage class B sub-class disregarding transients and ripple

highest value of AC voltage (rms) or of DC voltage that can occur under any normal operating conditions

rechargeable system that stores energy for delivery of electric energy for the electric driveExamples to

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

phenomenon or quantity which varies between two consecutive steady states during a short time

maximum voltage of a voltage class B sub-class disregarding transients and ripple

Note 1 to entry: Maximum working voltages within a voltage sub-class are less than or equal to the upper

classification of an electric component or circuit with a maximum working voltage of ≤ 30 V AC (rms) or

classification of an electric component or circuit with a maximum working voltage of (> 30 and

general term covering voltage sub-class, working voltages and deviations from working voltages