SAE J2907-2023 PDF

Full title and description

SAE J2907-2023 — Performance Characterization of Electrified Powertrain Motor‑Drive Subsystem. This SAE recommended practice defines a repeatable, consensus test procedure and reporting format for characterizing the performance (torque, speed, and power) of electrified propulsion motor‑drive subsystems (motor, mating power converter/inverter and controller) used for vehicle propulsion. The intent is to provide familiar, comparable performance ratings while avoiding test conditions that artificially bias results.

Abstract

SAE J2907-2023 provides test methods, instrumentation requirements, calculations, data recording templates and reporting conventions to measure and validate the performance characteristics of electric motor‑drive subsystems used in electrified vehicles. The document covers stabilized procedures for measuring stall torque, peak/continuous power (at manufacturer‑specified speeds and voltages), maximum available torque at operating voltage, and other performance metrics in a way that emphasizes repeatability and realistic, in‑service performance rather than best‑case results.

General information

• Status: Current / Stabilized (August 2023)
• Publication date: 01 August 2023 (Edition reference: J2907_202308)
• Publisher: SAE International (Society of Automotive Engineers)
• ICS / categories: 43.040 Road vehicle engineering; Automotive powertrain testing; Ground vehicle standards
• Edition / version: 2023 edition (J2907_202308), replaces earlier J2907 editions (2018, 2017)
• Number of pages: 25 (approx.)

Scope

This recommended practice specifies a consensus test procedure to obtain repeatable measurements that accurately reflect the performance of a propulsion electric drive subsystem used for vehicle propulsion, regardless of the subsystem complexity or number of energy sources. It defines what to measure, how to instrument and load the subsystem (typically using a calibrated dynamometer), required environmental and electrical conditions, calculation and reporting methods, and guidance to avoid intentional parameter biasing or assembly tolerances that would produce unrepresentative results. The scope focuses on subsystem‑level characterization (motor + inverter/controller) rather than whole‑vehicle testing, while remaining compatible with higher‑level vehicle power test methods.

Key topics and requirements

• Definition of the test object: motor + mating power converter(s)/controller as the motor‑drive subsystem under test.
• Measurement targets: stall torque, peak power at manufacturer‑specified speed, continuous/rated power, and maximum available torque at the specified operating voltage.
• Test instrumentation and accuracy: calibrated torque and speed measurement (dynamometer), voltage/current sensing, temperature monitoring and data acquisition requirements.
• Dynamometer and loading methods: recommended dynamometer types and control modes to apply realistic loads and capture transient and steady‑state behavior.
• Test conditions and conditioning procedures: ambient/environmental requirements, thermal conditioning, and procedures to achieve representative operating temperatures and cooling conditions.
• Data recording and templates: required data fields (operating voltage, speed range, torque, power, temperatures, measurement uncertainties) and standard formats for reporting.
• Calculations and corrections: formulas for converting measured torque/speed to shaft power, handling electrical losses, and documenting assumptions and uncertainty.
• Repeatability and anti‑bias guidance: instructions to avoid test setup or parameter selection that produces artificially optimized results; emphasis on typical in‑service performance.
• Applicability: guidance for multiple motor topologies and converter types; notes on multi‑source or hybrid arrangements when used as a propulsion subsystem.

Typical use and users

SAE J2907-2023 is used by OEM powertrain engineers, electric motor and inverter manufacturers, independent test laboratories, research institutions, suppliers of dynamometers and test instrumentation, and regulatory/consumer testing organizations that require consistent, comparable motor‑drive subsystem performance data. Typical applications include component development and validation, supplier acceptance testing, comparative product benchmarking, and generating manufacturer power ratings that can feed higher‑level vehicle power determinations.

Related standards

Related and commonly referenced documents include earlier editions of this practice (SAE J2907 — 2018, 2017), SAE J2908 (Vehicle Power and Rated System Power Test for Electrified Powertrains), SAE J1349 (engine net power procedures — used as a comparator for power rating conventions), and other SAE and international test procedures for electric propulsion, dynamometer testing and measurement uncertainty. Users should consult the normative/reference sections of the J2907 document for the definitive list of referenced standards.

Keywords

electrified powertrain; motor‑drive subsystem; electric motor; inverter; dynamometer; torque measurement; peak power; continuous power; performance characterization; SAE J2907-2023; test procedure; measurement repeatability; data reporting.

FAQ

Q: What is this standard?

A: SAE J2907-2023 is a recommended practice that specifies test methods and reporting conventions for characterizing the performance of electrified powertrain motor‑drive subsystems (motor plus mating power electronics and controller).

Q: What does it cover?

A: It covers test object definition, required instrumentation and dynamometer loading, test condition and conditioning procedures, data acquisition and reporting templates, calculations for power/torque, and guidance to ensure repeatable, representative measurements while avoiding artificially biased results.

Q: Who typically uses it?

A: Powertrain and motor manufacturers, OEM engineering teams, independent test labs, research organizations, and suppliers involved in component development, validation, supplier acceptance, and benchmarking of electric motor and drive subsystems.

Q: Is it current or superseded?

A: The 2023 edition (J2907_202308) is the current, stabilized edition (published August 1, 2023) and supersedes earlier J2907 editions (2018, 2017).

Q: Is it part of a series?

A: Yes. J2907 sits within SAE’s family of powertrain and electrification test documents. It complements related SAE documents such as J2908 (vehicle power and rated system power tests) and other SAE test procedures for propulsion and power ratings.

Q: What are the key keywords?

A: Electrified powertrain, motor‑drive subsystem, dynamometer testing, torque, peak power, continuous power, SAE J2907-2023, performance characterization, measurement repeatability.