1 Scope
This document specifies a method for evaluating the energy efficiency of rest stop systems for passenger cars. This document applies to vehicles of category M with a maximum design gross mass not exceeding 3500 kg that have a rest stop system. This document applies to vehicles that can run 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 through normative references in the text. Among them, the reference document with the date, only the version corresponding to the date applies to this document; the reference document without the date, its latest version (including all the revision sheet) applies 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 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 Terms and definitions
The terms defined in GB 27999 and the following terms and definitions apply to this document.
3.1 Idling start-stop system idlestart-stopsystem
A system that automatically switches off the engine when the vehicle is stopped or about to stop and the engine is at idle and restarts the engine according to the driver's operation or the vehicle's needs.
4 General requirements
4.1 The idle start/stop system should not affect the safe operation of the vehicle during operation.
4.2 The vehicle manufacturer or its authorised agent shall submit a vehicle representing the model under test to the inspection body, together with the following relevant information:
a) A description of the supplier of the key components of the rest stop system:.
b) A description of the function and use of the rest stop system. This includes the conditions for switching off and restarting the engine:
c) Idling speed of the engine;
d) List of manually switchable energy saving devices, including device names and functional descriptions, etc.
5 Test procedure
5.1 Determination of fuel consumption of the idle start/stop system
5.1.1 Before the test, the vehicle shall be warmed up by running at least one GST-Light Vehicle Test Cycle (WLTC) or Chinese Passenger Vehicle Driving Condition (CLTC-P) as specified in 4.3 of GB/T19233-2020 on the chassis dynamometer, with the selection of test cycles during the warm-up process being consistent with the test determined in 5.1.2.
5.1.2 The vehicle is tested according to one of the following methods. Each set of tests shall be carried out under the same test conditions (including the driver) and a total of 3 sets of tests shall be carried out, each set of tests shall keep the vehicle in a fully preheated condition, otherwise the preheating shall be carried out again in accordance with 5.1.1.
a) The vehicle shall be tested with the idle start-stop system on and off under WLTC and CLTC-P in accordance with the methods described in 6.1.6.2, 6.4 and 6.5 and 7.1~7.4 of GB/T19233-2020 respectively; for NOVC-HEV, the vehicle shall be tested with the idle start-stop system on and off in accordance with the methods described in 6.1 and 6.4 and 7.2 of GB/T19753--2021 respectively. For NOVC-HEVs, the tests are carried out under WLTC and CLTC-P, respectively, with the idle start-stop system on and off. The test items included in each test group are shown in Table 1.
b) The vehicle is tested with the idle start-stop system on at WLTC and CLTC-P in accordance with methods 6.1.6.2, 6.4 and 6.5 of GB/T19233-2020; for NOVC-HEV, the test is conducted at WLTC and CLTC-P in accordance with methods 6.1 and 6.4 of GB/T19753-2021, respectively. The test was carried out with the rest speed start/stop system on. During the test, the resting time (the time when the engine is switched off and the vehicle speed is zero) is recorded. The fuel consumption test was carried out with the rest stop system switched off and at idle. The vehicle should first run at rest for 3 min and then carry out a 2 min fuel consumption rate measurement at rest. The idling fuel consumption rate measurement time may be extended at the suggestion of the vehicle manufacturer and confirmed by the inspection body, but the total measurement time should not exceed 5 min. The fuel consumption rate test shall be carried out continuously after the test with the rest stop system on. The test items included in each group of tests are shown in Table 1.
5.2 Repeatability test Calculate the standard deviation σ of the 95th percentile distribution of the results of the 3 tests according to equation (2) and compare the difference between the maximum and minimum values (OF) of the 3 tests with the value of σ:
a) If F.... is not greater than σ. then it is considered to pass the repeatability test;
b) if 0... is greater than σ. then it is considered that it does not pass the repeatability test.
6 Test results
6.1 Test results on the energy saving effect of the idle start-stop system
6.1.1 For the test conducted in accordance with method 5.1.2 a), the results of the test on the energy saving effect of the idle start-stop system are calculated in accordance with equation (3). A frequency factor of 0.60 for vehicles that cannot manually switch off the idle stop system or vehicles with a rechargeable energy storage system (REESS) with a nominal voltage of 48V or higher, 0.80 for NOVC-HEVs, 1.00 for NOVC-HEVs, and K. An operating habit factor of 0.95 for manual transmissions and 1.00 for other transmission types.
6.1.2 For the test according to method 5.1.2 b). The results of the idle start-stop system energy saving test are calculated according to equation (4).
6.2 Idle start/stop system energy saving value The idle start/stop system energy saving value is calculated in accordance with equation (5).
Appendix A (normative)
Idle start/stop system test report
A.1 Basic information about the vehicle and the manufacturer
A.1.1 Trade name or make of the vehicle:
A.1.2 Vehicle type:.
A.1.3 Type of vehicle:
A.1.4 Name and address of the manufacturer:
A.1.5 Name and address of the legal representative of the manufacturer (if applicable): Description of the vehicle
A.2.1 Idle start/stop system information
A.2.1.1 Description of the supplier and type of key components of the idling system [starter motor, battery, ECU (hardware version number), generator (version number, type, supplier), type]:
A.2.1.2 Manual switch-off of the rest stop system possible; Yes/No
A.2.1.3 Nominal voltage of the idle start/stop system REESS:_
VA.2.2 Complete vehicle parameters.
A.2.2.1 Overall vehicle mass: kg
A.2.2.2 Maximum design gross mass:kg
A.2.2.3 Rated number of passengers
A.2.2.4 Body type:
A.2.2.5 Driving wheels: front and rear 4X4
A.2.3 Engine A.2.3.1 Engine type:
A.2.3.2 Engine type:
A.2.3.3 Engine displacement:L
A.2.3.4 Fuel injection system type: Common rail / mechanical pump / VE pump / monoblock pump / pump nozzle / other
A.2.3.5 Fuel recommended by the manufacturer: A.2.3.6 Maximum power:
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Test procedure
6 Test results
Appendix A (normative)
