ISO 21782-2:2019

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.