1 Scope
This document specifies a method for evaluating the energy efficiency of braking energy recovery systems for passenger cars.
This document applies to M1 vehicles with brake energy recovery systems with a maximum design gross mass of up to 3500 kg.
This document applies to vehicles capable of running on petrol or diesel, and does not apply to hybrid electric vehicles that can be charged externally.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text. Where a reference is dated, only the version corresponding to that date is applicable to this document; where a reference is not dated, the latest version (including all amendment sheets) is applicable to this document.
GB 18352.6-2016 Emission limits and measurement methods for light duty vehicles (China Stage 6)
GB/T 19233-2020 Test method for fuel consumption of light duty vehicles
GB 19578 Fuel Consumption Limits for Passenger Cars
GB/T 19596 Terminology for electric vehicles
GB/T 19753-2021 Test method for energy consumption of light-duty hybrid electric vehicles
GB 27999 Evaluation methods and indicators for fuel consumption of passenger cars
3 Terminology and definitions
The terms defined by GB/T 19596 and GB 27999 and the following terms and definitions apply to this document.
3.1
Rechargeable energy storage system
An energy storage system that is rechargeable and can provide electrical energy.
3.2
Braking energy recovery system
A system that converts or partially converts the kinetic and potential energy of a vehicle into energy stored in an on-board rechargeable energy storage system when the vehicle is coasting, decelerating or descending a slope.
3.3
Regenerative energy
The electrical energy recovered by regenerative braking of a moving vehicle.
Note: The unit is Watt-hour (W-h).
4 General requirements
4.1 The safe operation of the vehicle shall not be affected during the operation of the brake energy recovery system.
4.2 The vehicle under test shall comply with the requirements of the fuel consumption limit value specified in GB 19578 and the requirements of GB 18352.6-2016 (or other applicable versions) regarding pollutant emissions.
4.3 The setting of the brake energy recovery system of the vehicle under test shall be consistent with that of the certified test vehicle.
4.4 The test conditions shall meet the requirements of Chapter 5 of GB/T 19233-2020; for the non-externally rechargeable hybrid electric vehicle (NOVC-HEV), the test conditions shall meet the requirements of Chapter 4 of GB/T 19753-2021.
4.5 The brake energy recovery system shall be tested in accordance with the requirements of Chapter 5, and the vehicle parameters and test data for the test shall be recorded in accordance with the provisions of Appendix A. The energy saving effect shall be calculated in accordance with the requirements of Chapter 6 and the results shall be expressed in litres per 100 km (L/100km), rounded off (rounded off) to two decimal places.
5 Test procedure
5.1 Test requirements
5.1.1 If the vehicle is equipped with other energy saving devices that can be switched on and off manually, the switch shall be switched off during the test.
5.1.2 For NOVC-HEVs, the vehicle shall be pre-treated in accordance with C.3.2 of GB/T 19753-2021. For other vehicles, the state of charge (SOC) of REESS shall be set according to the recommended value of the vehicle manufacturer and recorded in the test report, and the state of charge shall be adjusted to the recommended value of the vehicle manufacturer before the start of each test.
5.1.3 The sampling frequency of the measured current shall not be less than 20 Hz.
5.1.4 For the purpose of using external equipment to measure the current and voltage at the motor terminals of all motors involved in brake energy recovery, suitable, safe and accessible connection points shall be provided on the vehicle.
5.2 Test method
5.2.1 The operating principle of the brake energy recovery system shall be provided by the vehicle manufacturer to the testing body and the regenerative energy shall be measured in accordance with the method specified in Appendix B.
5.2.2 Calculate the theoretical cycle recovery energy of the vehicle under the global harmonised light vehicle test cycle (WLTC) and Chinese passenger car driving conditions (CLTC-P) as specified in 4.3 of GB/T 19233-2020 in accordance with Appendix C.
6 Test results
6.1 Test results of the energy saving effect of the brake energy recovery system
The results of the braking energy recovery test were calculated according to equation (1).
6.2 Value of energy saving effect of brake energy recovery system
The energy saving effect value of the brake energy recovery system is calculated according to equation (6).
Appendix A (Normative) Brake Energy Recovery System Test Report
foreword
1 Scope
2 Normative references
3 Terminology and definitions
4 General requirements
5 Test procedure
6 Test results
Appendix A (Normative) Brake Energy Recovery System Test Report
