ISO 21782-2:2019

Electrically propelled road vehicles - Test specification for electric propulsion components - Part 2: Performance testing of the motor system

This document specifies the performance tests for the motor system designed as a voltage class B electric propulsion system for electrically propelled road vehicles.

Véhicules routiers à propulsion électrique — Spécification d'essai pour les composants de propulsion électrique — Partie 2: Essai de performance du système moteur

General Information

• Status: Published
• Publication Date: 28-Aug-2019
• ICS: 43.120 - Electric road vehicles
• Technical Committee: ISO/TC 22/SC 37 - Electrically propelled vehicles
• Drafting Committee: ISO/TC 22/SC 37/WG 4 - Systems and components connected to electric propulsion systems
• Current Stage: 9060 - Close of review
• Completion Date: 04-Mar-2030

Overview

ISO 21782-2:2019 - Electrically propelled road vehicles - Test specification for electric propulsion components - Part 2: Performance testing of the motor system - defines standardized laboratory tests for evaluating the performance of a voltage class B motor system (paired inverter + motor) used in electrically propelled road vehicles. The standard specifies test diagrams, conditions, measurement points and reporting rules to verify that motor systems meet designed performance and thermal limits.

Key topics and technical requirements

• Scope: Performance tests for the motor system as a voltage class B electric propulsion system; applies to the paired inverter-and-motor combination.
• Reference: Test conditions and definitions link to ISO 21782-1 for rated DC input voltage, ambient conditions and operating-point definitions.
• Principal tests included:
  • Measurement of total loss and total efficiency - measures inverter input power vs motor output power across specified operating points; prescribes averaging, recording and calculation methods to determine system efficiency and losses.
  • Temperature rise test - records temperature at defined points (motor coil high‑temperature points; inverter semiconductor/cooling interface; coolant inlet/outlet) to verify thermal behavior under steady and transient loads.
  • Torque characteristic test - maps torque vs speed at defined operating points to confirm torque capability per specification.
  • Torque ripple test - measures periodic torque variations (torque ripple) using torque/speed detectors and spectrum analysis to assess NVH and drivability implications.
• Test conditions: specifies DC input rated voltage, room temperature/humidity per ISO 21782-1, coolant/cooling-air flow, and a target coolant temperature (tests performed at 65 °C when technically feasible). Operating times and measuring intervals (e.g., averages of the last 1 s) are defined for repeatability.
• Data & reporting: test diagrams, required recording channels (torque, speed, inverter input voltage/current, temperatures), and test-report content are specified.

Practical applications

• Design verification and validation of motor + inverter assemblies during R&D.
• Supplier acceptance and production qualification for EV traction motors and inverters.
• Benchmarking and performance comparison across motor-system designs.
• Thermal management tuning and cooling-system validation.
• NVH (noise, vibration, harshness) assessment related to torque ripple.

Who should use this standard

• EV OEMs and powertrain engineers validating propulsion components.
• Motor and inverter manufacturers developing traction systems.
• Independent test laboratories and certification bodies performing compliance and performance testing.
• System integrators and suppliers preparing technical data for contracts or regulatory dossiers.

Related standards

• ISO 21782-1: General test conditions and definitions (normative reference for operating points, voltages and environmental conditions).

Keywords: ISO 21782-2:2019, motor system performance testing, electrically propelled road vehicles, voltage class B, inverter + motor testing, total efficiency, temperature rise test, torque characteristic, torque ripple.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21782-2
First edition
2019-08
Electrically propelled road vehicles —
Test specification for electric
propulsion components —
Part 2:
Performance testing of the motor
system
Reference number
©
ISO 2019
© ISO 2019
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
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CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
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Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 1
5 Tests . 1
5.1 Measurement of total loss and total efficiency . 1
5.1.1 General. 1
5.1.2 Test diagram . 1
5.1.3 Test conditions. 2
5.1.4 Test procedure . 3
5.2 Temperature rise test . 3
5.2.1 General. 3
5.2.2 Test diagram . 3
5.2.3 Test conditions. 4
5.2.4 Test procedure . 5
5.3 Torque characteristic test . 5
5.3.1 General. 5
5.3.2 Test diagram . 5
5.3.3 Test conditions. 6
5.3.4 Test procedure . 7
5.4 Torque ripple test . 7
5.4.1 General. 7
5.4.2 Test diagram . 7
5.4.3 Test conditions. 7
5.4.4 Test procedure . 8
6 Test reports . 8
Annex A (informative) Test reports . 9
Bibliography .12
Foreword
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.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 21782 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.
iv © ISO 2019 – All rights reserved

INTERNATIONAL STANDARD ISO 21782-2:2019(E)
Electrically propelled road vehicles — Test specification
for electric propulsion components —
Part 2:
Performance testing of the motor system
1 Scope
This document specifies the performance tests for the motor system designed as a voltage class B
electric propulsion system for electrically propelled road 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 21782-1, Electrically propelled road vehicles — Test specification for electric propulsion components
— Part 1: General test conditions and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21782-1 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/
4 Abbreviated terms
For the purposes of this document, the abbreviated terms given in ISO 21782-1 apply.
5 Tests
5.1 Measurement of total loss and total efficiency
5.1.1 General
Under the conditions of the paired inverter and motor combination, this test measures total loss and
total efficiency between the input power of the inverter and the output power of the motor in order to
ensure that the performance of the motor system is as designed.
5.1.2 Test diagram
The test diagram is shown in Figure 1.
Key
1 DUT
2 test motor
3 test inverter
4 DC power supply
5 load
6 torque/speed detector
7 spectrum analyser/power meter
8 torque/speed meter
9 inverter input current (in A)
10 inverter input voltage (in V)
11 motor torque (in Nm)
-1
12 motor speed (in min )
Figure 1 — Diagram for total loss and total efficiency test of the motor system
5.1.3 Test conditions
The test conditions are shown in Table 1.
Table 1 — Conditions for total loss and total efficiency test of the motor system
Test conditions Value Remark
DC input voltage Rated voltage as defined in ISO 21782-1:2019, 3.22. For the DC input voltage toler-
ance, see ISO 21782-1:2019, 5.3.
Ambient conditions Room temperature (RT) and humidity as defined in
ISO 21782-1:2019, 5.4.
Coolant temperature Maximum temperature for unlimited operating — In case of liquid cooling
capability
— Ethylene glycol and pro-
pylene glycol as examples of
coolant
— If technically feasible, the
tests shall be performed at
coolant temperature of 65 °C.
Otherwise the deviation shall
be documented in the test
report.
Coolant flow rate Minimum flow rate for unlimited operating capability In case of liquid cooling
Cooling air flow rate Minimum flow rate for unlimited operating capability In case of air cooling
2 © ISO 2019 – All rights reserved

Table 1 (continued)
Test conditions Value Remark
Operating point Test points as defined in ISO 21782-1:2019, Figure 1
— "a", "a’", "b", "p " to "p " (optional "e", "e’", "f", "
...