ISO 20762:2018

Electrically propelled road vehicles — Determination of power for propulsion of hybrid electric vehicle

This document specifies measurement methods for the maximum system propulsion power of hybrid-electric vehicles (HEV). The results can be compared with the data of internal combustion engine vehicles (ICEV) power measured with the relevant current method. NOTE ISO 1585 and UN Regulation No. 85, for example. This document applies only to the vehicles with the following characteristics: — HEVs with an internal combustion engine (ICE) and one or more electric motors powered by one or more rechargeable energy storage systems (RESS) for propulsion; — vehicles classified as passenger cars or light duty trucks.

Véhicules routiers à propulsion électrique — Détermination de la puissance de propulsion des véhicules hybrides

General Information

• Status: Published
• Publication Date: 23-Aug-2018
• ICS: 43.120 - Electric road vehicles
• Technical Committee: ISO/TC 22/SC 37 - Electrically propelled vehicles
• Drafting Committee: ISO/TC 22/SC 37/WG 2 - Performance and energy consumption
• Current Stage: 6060 - International Standard published
• Start Date: 24-Aug-2018
• Completion Date: 24-Aug-2018

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 20762
First edition
2018-09
Electrically propelled road vehicles —
Determination of power for
propulsion of hybrid electric vehicle
Véhicules routiers à propulsion électrique — Détermination de la
puissance de propulsion des véhicules hybrides
Reference number
ISO 20762:2018(E)
ISO 2018
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ISO 20762:2018(E)
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© ISO 2018

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ii © ISO 2018 – All rights reserved
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ISO 20762:2018(E)
Contents Page

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

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

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

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

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

4 Symbols and abbreviated terms ........................................................................................................................................................... 2

5 Test condition .......................................................................................................................................................................................................... 2

5.1 Test instrumentation ......................................................................................................................................................................... 2

5.1.1 Chassis dynamometer ................................................................................................................................................. 2

5.1.2 Test room ................................................................................................................................................................................ 2

5.1.3 Cooling fan ............................................................................................................................................................................. 2

5.2 Measurement ............................................................................................................................................................................................ 3

5.2.1 Measurement items and accuracy .................................................................................................................... 3

5.2.2 Measurement frequency ........................................................................................................................................... 3

6 Test procedure ........................................................................................................................................................................................................ 3

6.1 General ........................................................................................................................................................................................................... 3

6.2 Preparation of chassis dynamometer.................................................................................................................................. 4

6.2.1 Roller .......................................................................................................................................................................................... 4

6.2.2 Tire slippage ........................................................................................................................................................................ 4

6.2.3 Chassis dynamometer warm-up......................................................................................................................... 4

6.2.4 Chassis dynamometer control .............................................................................................................................. 4

6.3 Preparation of vehicle ....................................................................................................................................................................... 4

6.4 Preparation of measurement devices ................................................................................................................................. 4

6.5 Initial charge of RESS......................................................................................................................................................................... 4

6.6 Vehicle soak ............................................................................................................................................................................................... 5

6.7 Vehicle installation .............................................................................................................................................................................. 5

6.8 Test sequence ........................................................................................................................................................................................... 5

6.8.1 General...................................................................................................................................................................................... 5

6.8.2 Vehicle conditioning...................................................................................................................................................... 5

6.8.3 RESS adjustment .............................................................................................................................................................. 5

6.8.4 Vehicle operation ............................................................................................................................................................. 5

6.8.5 Pedal operation ................................................................................................................................................................. 6

6.8.6 End of vehicle running ................................................................................................................................................ 6

6.9 Calculation of HEV system power ........................................................................................................................................... 6

6.9.1 General...................................................................................................................................................................................... 6

6.9.2 Calculation for TP1......................................................................................................................................................... 6

6.9.3 Calculation for TP2......................................................................................................................................................... 7

6.10 Determination of maximum HEV system power ....................................................................................................... 9

7 Test report ................................................................................................................................................................................................................10

7.1 General ........................................................................................................................................................................................................10

7.2 Calculated values based on measured data .................................................................................................................10

7.3 Measured data ......................................................................................................................................................................................11

7.4 Environmental data .........................................................................................................................................................................12

7.5 Assumed values ...................................................................................................................................................................................12

7.6 General vehicle data based on the manufacturer's information (informative) ............................12

Annex A (informative) Examples for gearbox system efficiency factor (includes gearbox and

differential) at maximum HEV system power .....................................................................................................................13

Bibliography .............................................................................................................................................................................................................................17

© ISO 2018 – All rights reserved iii
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ISO 20762:2018(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 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 the following

URL: 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.
iv © ISO 2018 – All rights reserved
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ISO 20762:2018(E)
Introduction

It is necessary for vehicle manufacturers to show the reasonable value of the power of hybrid-electric

vehicle (HEV) system and compare it with the value of the internal combustion engine (ICE) power

measured in the existing test methods such as ISO 1585 and UN Regulation No. 85. But at present, there

is no international evaluation method for the power of HEV systems available. Vehicle manufacturers

indicate the power of HEVs in their catalogues based on their individual calculation method. With the

method in this document, it is possible to measure and compare the power of any HEV topology with

those of internal combustion engine vehicles (ICEV).
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INTERNATIONAL STANDARD ISO 20762:2018(E)
Electrically propelled road vehicles — Determination of
power for propulsion of hybrid electric vehicle
1 Scope

This document specifies measurement methods for the maximum system propulsion power of hybrid-

electric vehicles (HEV).

The results can be compared with the data of internal combustion engine vehicles (ICEV) power

measured with the relevant current method.
NOTE ISO 1585 and UN Regulation No. 85, for example.
This document applies only to the vehicles with the following characteristics:

— HEVs with an internal combustion engine (ICE) and one or more electric motors powered by one or

more rechargeable energy storage systems (RESS) for propulsion;
— vehicles classified as passenger cars or light duty trucks.
This document does not apply to fuel cell vehicles.
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.

ISO 1585, Road vehicles — Engine test code — Net power

ISO 23274 (all parts), Hybrid-electric road vehicles — Exhaust emissions and fuel consumption

measurements
ISO/TR 8713, Electrically propelled road vehicles — Vocabulary
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 1585, ISO 23274 (all parts),

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
hybrid-electric vehicle
HEV

vehicle with both a rechargeable energy storage system (3.3) and a fuelled power source for propulsion

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ISO 20762:2018(E)
3.2
externally chargeable HEV

hybrid-electric vehicle (3.1) with a rechargeable energy storage system (3.3) that is intended to be charged

from an external electric energy source

Note 1 to entry: External charge for the purpose of conditioning of the RESS is not included.

Note 2 to entry: Externally chargeable HEVs are widely known as plug-in HEVs (PHEVs).

3.3
rechargeable energy storage system
RESS

system that stores energy for delivery of electric power and which is rechargeable

EXAMPLE Batteries or capacitors.
4 Symbols and abbreviated terms
AWD all wheel drive
ICE internal combustion engine
ICEV internal combustion engine vehicle
SOC state of charge
UN United Nations
5 Test condition
5.1 Test instrumentation
5.1.1 Chassis dynamometer

The chassis dynamometer shall have the absorption capacity for the vehicle propulsion power by fixed

speed control.
5.1.2 Test room
Conditions of the test room shall be adjusted as follows:
— reference temperature: 298 K ± 10 K (25 °C ± 10 °C);
— test atmospheric conditions, Pd: 80 kPa < Pd < 110 kPa.
5.1.3 Cooling fan

Fans shall be used to cool the vehicle to maintain the proper operating temperature. However, excessive

cooling is prohibited. Air speed in front of the vehicle shall not be higher than the vehicle speed.

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ISO 20762:2018(E)
5.2 Measurement
5.2.1 Measurement items and accuracy
Table 1 — List of items
Items Unit Accuracy Remark
±10 min or ±0,5 %
Engine speed min of measured value
whichever is greater
Intake manifold pressure means inlet de-
Intake manifold pressure Pa ±50 Pa
pression as used in ISO 1585.
Atmospheric pressure Pa ±100 Pa
At least used for compression-ignition
engines, and for ICEs if the confirmation
Fuel flow rate g/s ±3 %
of air fuel ratio according to ISO 1585 is
necessary.
Voltage V ±0,5 %
The current transducer shall have a min-
imum accuracy of 0,5 % of the measured
Current A ±0,5 %
value or 0,1 % of the maximum value of
the scale.
Room temperature K ±2 K
Chassis dynamometer roller ±0,5 km/h or ±1 %,
km/h
speed whichever is greater
Time s ±0,01 s
Drive shaft or wheel rotation- ±0,05 s or ±1 %,
al speed whichever is greater
±6 Nm or ±0,5 %,
Drive shaft or wheel torque Nm
whichever is greater

Measurement devices shall be of certified accuracy, traceable to an approved regional or international

standard.
5.2.2 Measurement frequency

All the items in Table 1, except atmospheric pressure and room temperature, shall be measured and

recorded at a frequency of not less than 10 Hz.

The items atmospheric pressure and room temperature shall be at least recorded as single measurement

activity at start of vehicle operation (see 6.8.4) and after end of vehicle running (see 6.8.6).

6 Test procedure
6.1 General

The purpose of the following test procedures is to determine the maximum system propulsion power

of an HEV (maximum HEV system power) on a chassis dynamometer at fixed speeds. Two optional test

procedures are applicable, namely:

— a test procedure via measured RESS power and determined ICE power, consecutively named test

procedure option 1 (TP1); and

— a test procedure via torque and speed measurement at the drive shaft(s) or wheel(s), consecutively

named test procedure option 2 (TP2).
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ISO 20762:2018(E)

The test result for the maximum HEV system power shall be stated always in connection with the

performed test procedure.

NOTE Depending on the power transfer rate in series and power-split types, the results for the maximum

HEV system power differ in TP1 and TP2.
6.2 Preparation of chassis dynamometer
6.2.1 Roller

The chassis dynamometer roller(s) shall be clean, dry and free from foreign material which can cause

tire slippage.
6.2.2 Tire slippage

Additional weight may be placed on or in the vehicle to eliminate tire slippage. The use of any additional

weight shall be recorded.
6.2.3 Chassis dynamometer warm-up

The chassis dynamometer shall be warmed up in accordance with the dynamometer manufacturer’s

recommendations, or as appropriate.
6.2.4 Chassis dynamometer control

The chassis dynamometer shall be controlled in fixed speed mode for the power test. Only for the

requirements towards vehicle conditioning (6.8.2), the chassis dynamometer shall be controlled in

road load mode.
6.3 Preparation of vehicle

The tire pressure shall be adjusted in accordance with the vehicle manufacturer’s recommendations or

the owner’s manual. The vehicle lubricants and levels specified by the manufacturer shall be used.

Fuel shall be selected in accordance with the vehicle manufacturer's recommendations. If there are no

recommendations, the fuel specified in ISO 1585 shall be used.
6.4 Preparation of measurement devices

The measurement devices shall be installed at suitable position(s) and warmed up as appropriate.

Specifically for TP2, the gearbox output shaft(s) or the drive
...