ISO 23274-2:2021

This document specifies a chassis dynamometer test procedure to determine the end of the charge-depleting state (CD) and consumed electric energy during CD state. The identification of the end of the CD state is an important step for procedures to determine exhaust emissions and fuel consumption. Final determination of exhaust emissions and fuel consumption is not included in this document. This document applies to vehicles with the following characteristics. —    The vehicles are hybrid-electric road vehicles (HEV) with an internal combustion engine (ICE) and an on-board rechargeable energy storage system (RESS) for vehicle propulsion which is supplied with electric energy from an external electric power source. —    A CD state, in which the electric energy in the RESS from an external electric power source is consumed, is followed by a charge-sustaining (CS) state in which the fuel energy is consumed sustaining the electric energy of the RESS. —    Only batteries are assumed as the RESS of a vehicle. —    The RESS is not charged while driving unless by regenerative braking and/or by generative operation driven via the ICE. —    External charge for the purpose of conditioning of the RESS is not included. NOTE 1   Trolleybuses and solar powered vehicles are not included in the scope. —    The vehicle is classified as a passenger car or light duty truck, as defined in the relevant regional applicable driving test (ADT) standard. —    For the ICE, only liquid fuels (for example, gasoline and diesel fuel) are used. NOTE 2   In the case of vehicles with ICE using other fuel [for example, compressed natural gas (CNG), hydrogen (H2)], this document can apply except the measurement of consumed fuel; otherwise the measurement method for those using the corresponding fuel can apply. —    The nominal energy of the RESS is at least 2 % of the total energy of consumed fuel over an ADT