Overview
ISO 20762:2018 - Electrically propelled road vehicles - Determination of power for propulsion of hybrid electric vehicle - defines standardized measurement methods to determine the maximum system propulsion power of hybrid electric vehicles (HEVs). It enables HEV power results to be compared with internal combustion engine vehicle (ICEV) ratings obtained by established methods (for example ISO 1585, UN Regulation No. 85). The standard applies to passenger cars and light‑duty trucks with an ICE plus one or more electric motors and rechargeable energy storage systems (RESS). Fuel‑cell vehicles are excluded.
Key technical topics and requirements
- Test instrumentation and environment
- Chassis dynamometer with fixed‑speed control and adequate absorption capacity.
- Test room conditions: reference temperature ≈ 298 K (25 °C) ±10 K; atmospheric pressure Pd between 80 kPa and 110 kPa.
- Cooling fans allowed but air speed in front of the vehicle must not exceed vehicle speed.
- Measurement items and accuracy
- Required measurements include torque, rotational speed (drive shaft/wheel), voltage, current, fuel flow, intake manifold pressure, room temperature and atmospheric pressure.
- Typical accuracy requirements (as specified): voltage ±0.5%, current ±0.5% (or 0.1% of scale max), room temperature ±2 K, torque ±6 N·m or ±0.5% (whichever greater), roller speed ±0.5 km/h or ±1%.
- All primary signals (except atmospheric pressure and room temperature) must be recorded at ≥10 Hz.
- Test procedures
- Two optional procedures:
- TP1 - calculate system power from measured RESS (electric) power plus determined ICE power.
- TP2 - measure torque and speed at drive shaft(s) or wheel(s) and calculate system power directly.
- The standard describes vehicle conditioning, RESS initial charge, chassis dynamometer setup, pedal operation rules, and computation of maximum HEV system power.
- Reporting
- Detailed test report content requirements, including measured data, calculated values, environmental data, and assumed values. Annex A provides gearbox/differential efficiency examples.
Practical applications and users
- Who uses it:
- Vehicle manufacturers (catalog power verification and competitive comparisons)
- Independent test laboratories and certification bodies
- R&D teams validating HEV propulsion system performance
- Regulators and compliance auditors comparing HEV power claims with ICEV norms
- Common uses:
- Objective, repeatable measurement of HEV propulsion power for specification sheets, compliance, benchmarking and design validation.
- Harmonized comparison between diverse HEV topologies (series, parallel, power‑split) and conventional ICE vehicles.
Related standards
- 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
- UN Regulation No. 85 - (example regulatory method for ICE power)
Keywords: ISO 20762:2018, HEV system power, hybrid electric vehicle power measurement, chassis dynamometer, RESS, TP1, TP2, ISO standard.
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