Electric Motor Test — Automotive Traction Motors

What Is Electric Motor?

The electric motor test evaluates the motor providing propulsion in electric vehicles for its torque–speed characteristic, efficiency map, thermal behaviour and durability. Since the motor and inverter operate together, tests are mostly carried out as a motor–inverter set.

Purpose of Electric Motor

The purpose is to verify that the motor delivers its declared torque and power under defined conditions, meets efficiency targets, and does not exceed thermal limits under continuous operation.

Which Products Is Electric Motor Applied To?

Permanent-magnet synchronous motors (PMSM)
Asynchronous (induction) traction motors
Wound-rotor synchronous motors
Integrated e-axle units

In Which Sectors Is Electric Motor Used?

AutomotiveElectrical & ElectronicsMachinery

Standards Related to Electric Motor

IEC 60034 series
ISO 21782 series
UNECE R85
ISO 6469-3
ISO 16750 series

Electric Motor Conditions

Operating points: Sweep across the torque–speed plane; the point set per the customer's specification
Cooling: At the declared coolant temperature and flow rate
Winding temperature: Monitored to stay within the limit permitted by the insulation class

Equipment for Electric Motor

Motor dynamometer (high-speed capability)
High-power DC source and inverter
Power analyser
Torque and speed measurement system
Cooling conditioning unit
Winding-temperature measurement system
Vibration and acoustic measurement equipment

Sample Requirements for Electric Motor

Motor and, if present, the integrated reduction gear
A compatible inverter for control
Cooling interfaces and sensor connections
Winding resistance, pole count and insulation-class information must be provided

Duration of Electric Motor

Efficiency mapping and performance verification take a few days; durability and thermal-cycling tests can take weeks.

Electric Motor Procedure

1The motor is connected to the dynamometer and cooling is conditioned.
2Winding-resistance and insulation measurements are taken.
3Operating points across the torque–speed plane are swept, producing an efficiency map.
4Peak-power and continuous-power endurance are verified.
5A thermal-equilibrium test is carried out and winding temperatures are monitored.
6Overspeed and endurance tests are applied.
7Vibration and acoustic measurements are taken.

Electric Motor Acceptance Criteria

Torque, power and efficiency acceptance criteria come from the customer's specification. The winding-temperature limit tied to the insulation class is defined under IEC 60034 and must not be exceeded.

Evaluation of Results

The efficiency map, the width of the continuous-power region, and thermal-equilibrium temperatures are evaluated. In permanent-magnet motors, the risk of magnet demagnetisation at high temperature is also addressed.

Electric Motor Report

Motor description, type and rated values
Efficiency map and torque–speed curves
Thermal-measurement results
Insulation and winding-resistance measurements
Vibration and acoustic findings

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

UNECE R85 (net power declaration)
ISO 6469-3

Otomotiv Testleri — What Does This Testing Field Cover?

The section below describes the field that the Electric Motor test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Automotive testing shows that a component keeps working under conditions representing the loads it will meet over the life of the vehicle. A vehicle is not a single product but an ENVIRONMENT: vibration, temperature cycling, salt water, stone impact, electrical transients and electromagnetic noise are all present at the same time and for years.

What distinguishes this family is that VEHICLE MANUFACTURER SPECIFICATIONS sit on top of the standards. ISO and SAE publications establish the common ground; but Volkswagen, BMW, Ford, Stellantis, Toyota and Renault define different severity levels, additional tests and different acceptance criteria in their own specifications. For a component, the phrase "complies with automotive standards" is not sufficient on its own; which manufacturer's specification, and which revision of it, must be answered.

The family carries three separate processes together and they are often confused. Homologation covers the type approvals a vehicle needs to enter traffic and runs under state authority. Supplier approval means passing the vehicle manufacturer's own quality and testing requirements and is a commercial relationship. The third is design verification: the engineering team demonstrating that its own design meets its targets.

At component level the test plan is built around the LOCATION OF USE. A module in the engine bay and a module in the boot do not go through the same temperature and vibration profile; a component inside a door and one in the roof console do not see the same water and dust exposure. The ISO 16750 series is the common framework for this location-based approach.

The shift to electric vehicles has reshaped the field. High-voltage safety, insulation coordination, battery safety, charging interface conformity and the electromagnetic behaviour of high-voltage components have been added to the classical automotive test set. In a quiet vehicle, acoustic and vibration expectations have changed too; sounds once masked by the combustion engine are now audible.

The quality system side cannot be separated from testing in this field. A manufacturer under IATF 16949 presents test results in the PPAP file; measurement system analysis, process capability study and the control plan stand around the test report. A single good result is not enough — the process must be shown to be able to repeat it.

Method groups in this field

Environmental and climatic
Temperature cycling, thermal shock, damp heat, salt spray, dust and water ingress (IP), solar radiation. Severity levels vary with the mounting location.
Mechanical
Sine and random vibration, shock, mechanical loads, fastener torque and durability cycles.
Electrical
Supply voltage variations, transients (ISO 7637), reverse polarity, overvoltage, short circuit and sleep current measurements.
EMC
Component emissions (CISPR 25), radiated and conducted immunity (ISO 11452 series), electrostatic discharge (ISO 10605).
Materials and emissions
Odour, fogging and VOC emissions from interior materials; flammability; UV ageing; coating durability and stone impact.
Functional safety and cyber security
Functional safety evidence under ISO 26262 and cyber security engineering under ISO/SAE 21434; these are tied to regulation through UNECE R155 and R156.

Commonly confused in this field

An automotive report without a specification reference is not accepted in the supply chain; which OEM specification and revision was applied must be stated.
Type approval and supplier approval are different processes. A component with E-Mark approval is not thereby considered to have passed the OEM's own acceptance tests.
A result obtained on a prototype does not carry over to series production; PPAP is done with series production parts.
On the EMC side, measuring emissions alone is incomplete; immunity is a separate body of work and is more critical in a vehicle.
On electric vehicle components, high-voltage safety is a distinct competence; classical 12 V test infrastructure is not sufficient.

Which decisions these results support

Supplier component approval and the PPAP file
UNECE type approval and E-Mark marking
Design verification and durability evidence
Root cause analysis of field complaints and warranty returns
Assessing the impact of a design or supplier change

Related Tests

Frequently Asked Questions About Electric Motor

Under what condition is the declared power measured?

For vehicle type approval, the net power declaration is measured under the conditions defined in UNECE R85. Peak-power values seen in catalogues are generally short-duration and differ from continuous power; the two are recorded separately in the report.