Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization — Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 19754-2015 Test methods for energy consumption of light-duty hybrid electric vehicles. In addition to structural adjustment and editorial changes, the following main technical changes have been made with respect to GB/T 19754-2015:
a) The scope has been modified, and regulations for inapplicable model and reference model have been added (see Clause 1; Clause 1 of 2015 edition);
b) Terms and definitions of ultracapacitor state of charge, net energy change, propulsion energy, propulsion system, regenerative braking, total fuel energy, total fuel propulsion energy and total cycle propulsion energy have been deleted (see 3.1 ~ 3.8 of 2015 edition);
c) The determination method for NEC relative change has been modified (see 4.3; 4.3 of 2015 edition);
d) The test cycle has been modified from CCBC and C-WTVC to China heavy-duty commercial vehicle test cycle (CHTC), and the correction method of the test cycle when the maximum speed of the vehicle is less than that of CHTC has been added (see Clause 5, Clause 5 of 2015 edition);
e) The test conditions have been modified, the ambient temperature requirements for road tests deleted, and the ambient temperature requirements for chassis dynamometer tests modified (see 6.1; 6.1 in 2015 edition);
f) The tolerance requirements for test cycles have been modified, the requirement that the cumulative time exceeding the tolerance range for each test cycle shall not exceed 15 s has been added (see 6.3.6; 6.3.6 in 2015 edition);
g) The requirements for test fuels have been added, and vehicle test preparation and pretreatment removed (see 6.3.8; 6.3.8 of 2015 edition);
h) The measurement of coasting resistance and the technical conditions of chassis dynamometer have been modified, and other relevant documents instead of the content of this document quoted (see 6.5; 6.5 and 6.6.2 of 2015 edition);
i) The test equipment has been modified, and equipment requirements for measuring natural gas added (see 5.2; 5.2 of 2015 edition);
j) The test flow has been added (see 7.2);
k) The requirements of vehicle immersion test between test cycles from 15 min to no more than 30 min (see 7.3.2, 7.4.2.1.4, 7.4.3.1.2; 7.3.3 of 2015 edition);
l) The pre-set of REESS has been modified (see 7.4.1; 7.4.1 of 2015 edition);
m) The test methods for battery electric driving range stage, REESS energy adjustment stage and electric energy balance stage have been modified, and the test methods of battery electric driving range stage modified from constant velocity method to working condition method (see 7.4.2.3 ~ 7.4.2.5; 7.4.2.3 ~ 7.4.2.5 of 2015 edition);
n) Charging and electricity measurement of the vehicle after the test has been added (see 7.4.2.6);
o) The carbon balance method has been added to measure fuel consumption (see 8.5);
p) Judging conditions for effective test have been modified (see 8.7.2; 8.7.2 of 2015 edition);
q) The calculation method of test results in the battery electric driving range stage, REESS energy adjustment stage and electric energy balance stage have been modified (see 8.7.3.1.2 ~ 8.7.3.1.4; 8.7.3.1.2 ~ 8.7.3.1.4 of 2015 edition);
r) The comprehensive vehicle energy consumption results have been added (see 8.7.3.1.5 and 8.7.3.2.3);
s) The calculation method for converted fuel consumption has been added (see 8.7.3.1.6, 8.7.3.2.4 and Annex D);
t) The calculation method of CO2 emissions has been added (see 8.8);
u) Requirements for test validity have been deleted (8.8 of 2015 edition);
v) The calculation method for the battery electric utility factor has been added (see Annex C);
w) The bus cycle data of typical cities in China and the driving cycle data and instructions of heavy-duty vehicles in the United States have been deleted (see Annexes B ~ D of 2015 edition).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by the Ministry of Industry and Information Technology of the People's Republic of China.
This standard is under the jurisdiction of the National Technical Committee of Auto Standardization (SAC/TC 114).
This document was issued in 2005 as first edition, its first revision was issued in 2015, and this is the second revision.
Test methods for energy consumption of heavy-duty hybrid electric vehicles
1 Scope
This standard specifies the test method for energy consumption of heavy-duty hybrid electric vehicles on chassis dynamometers.
This document is applicable to hybrid electric vehicles with a maximum total mass exceeding 3,500kg, including trucks, semi-trailer tractors, buses, dump trucks and city buses. The relevant measurement methods of dump trucks may be referred for concrete mixer trucks, and the relevant measurement methods of trucks for other special transport vehicles.
This standard is applicable to vehicles driven by gasoline or diesel oil as well as vehicles driven by other fuels.
This standard does not apply to special operation vehicles, including van-type special operation vehicles, tank-type special operation vehicles, special dump operation vehicles, warehouse-gate special operation vehicles, lifting special operation vehicles and specially-structured special operation vehicles.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1884 Crude petroleum and liquid petroleum products — Laboratory determination of density — Hydrometer method
GB/T 3730.1 Motor vehicles and trailers — Types — Terms and definitions
GB/T 12534 Motor vehicles — General rules of road test method
GB/T 15089 Classification of power-driven vehicles and trailers
GB 17691-2018 Limits and measurement methods for emissions from diesel fuelled heavy-duty vehicles (CHINA VI)
GB 18352.6-2016 Limits and measurement methods for emissions from light-duty vehicles
GB/T 19596 Terminology of electric vehicles
GB/T 27840 Fuel consumption test methods for heavy-duty commercial vehicles
GB/T 38146.2-2019 China automotive test cycle — Part 2: Heavy-duty commercial vehicles
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 3730.1, GB/T 15089, GB/T 19596 and GB/T 38146.2-2019 apply.
4 Calculation method for net energy change (NEC)
4.1 General requirements
The energy change of the rechargeable electric energy storage system (REESS) shall be monitored during the vehicle movement and test process.
4.2 Determination of NEC
4.2.1 NEC of traction battery
The NEC of the traction battery may be calculated by Formulae (1), (2) and (3):
NEC＝k × ∫Pdt (1)
P＝k1 × U×I (2)
(3)
where,
NEC——the net energy change, kWh;
k——the unit conversion factor, 10-3, kW/W;
P——the discharge power of the traction battery, W;
t——time, s;
k1——the unit conversion factor, 3,600-1, h/s;
U——the terminal voltage of the traction battery, V;
I——the terminal current of the traction battery, A;
ηc——the charging electricity efficiency of traction battery;
Ic——the current input to the traction battery bus, A;
Id——the current output from the traction battery bus, A;
ηd——the discharging electricity efficiency of the traction battery.
See A.1 in Annex for the values of the electricity efficiency of charging and discharging.
4.2.2 NEC for ultracapacitor
See Formula (4) for the calculation of NEC for ultracapacitor:
(4)
where,
k2——the unit conversion factor, 3,600,000-1, kWh/Ws;
C——the rated capacity of the ultracapacitor, F;
Ue——the voltage of the ultracapacitor bus at the ending of the test cycle, V;
Ub——the voltage of the ultracapacitor bus at the beginning of the test cycle, V.
4.3 Determination of NEC relative change
NEC relative change is defined as the ratio of the NEC converted to the wheel to the total cycle propulsion energy, and is calculated by Formula (5):
(5)
where,
NECre——the NEC relative change;
ηtr——the transmission efficiency, with recommended value of 83%;
Ecycle——the total cycle propulsion energy (in kWh), which is calculated through the unit conversion factor k2 of Formula (4) according to the relevant regulations of Attachment CE.5 of GB 18352.6-2016.
According to the suggestions of the automobile manufacturer and confirmed by the inspection body, ηtr may be replaced by the recommended value of the automobile manufacturer, at which time ηt shall be indicated in the test report.
5 Test cycle
5.1 The fuel consumption of vehicles is measured according to China heavy-duty commercial vehicle test cycle (CHTC) specified in Annex A of GB/T 38146.2-2019. Among them, the city buses adopt CHTC-B test cycles; buses (excluding city buses) adopt CHTC-C test cycle; trucks (excluding dump trucks) adopt CHTC-LT (GVW ≤ 5,500 kg) or CHTC-HT (GVW > 5,500 kg) test cycles; the dump trucks adopt CHTC-D test cycles; and the semi-trailer tractors adopt CHTC-TT test cycles.
5.2 If the maximum speed of the vehicle is less than that of the CLTC, the test cycle shall be corrected in accordance with the regulations of Attachment CA.5 in GB 18352.6-2016 if the target speed is greater than the maximum speed of the vehicle.
6 Test preparation
6.1 Test conditions
6.1.1 Recommended ambient temperature is (23 ± 5)°C. The ambient temperature range may be relaxed to 5°C～35°C upon recommended by the automobile manufacturer and confirmed by the inspection body. During the test and at the beginning and end of the test, the temperature shall not exceed this range, and the actual ambient temperature shall be indicated in the test report.
6.1.2 The test site shall be equipped with traction battery ventilation and cooling devices, flywheel guard, anti-high pressure safety device, and other necessary safety protection facilities. During the test, a fixed speed fan may be used to direct cooling air to the vehicle to ensure that the engine working temperature meets the requirements of the manufacturer. The fan may only work when the vehicle is running, and shall be turned off when the vehicle stops.
6.2 Pre-collection of vehicle data
6.2.1 Prior to the test, the vehicle parameters shall be recorded in detail in accordance with the content of Annex B.
6.2.2 Any content that differs from the basic program, such as a test vehicle runs in a mode different from hybrid electric vehicles, shall be fully recorded for subsequent test to reproduce the test.
6.3 Vehicle conditions
6.3.1 Running-in
Before the test, the vehicle shall travel in accordance with the requirements of the automobile manufacturer, or run for not exceeding 10,000 km.
6.3.2 Vehicle status
The vehicle status shall be checked before the test:
——The performance of the test vehicle shall meet the requirements of the automobile manufacturer and be capable of running normally;
——The engine, motor and vehicle controls shall be adjusted according to the requirements of the automobile manufacturer;
——If the vehicle's cooling fan is temperature-controlled, it shall be kept in normal working condition, and the air conditioning system in the passenger compartment shall be turned off.
6.3.3 Test vehicle load
6.3.3.1 For city buses, the test shall be carried out at 65% of the maximum design loading mass. The setting of road load shall refer to the coasting test specified in GB/T 27840, and shall be based on the suggestions of the automobile manufacturer and confirmed by the inspection body. The road load may also be set based on the interpolation calculation of the recommended scheme of driving resistance coefficient specified in GB/T 27840, or subjected to testing under the state of maximum mass, and the setting of road load may refer to the coasting test or recommended scheme of driving resistance coefficient specified in GB/T 27840; for other heavy-duty commercial vehicles, the test shall be carried out at the state of maximum mass, and the road load shall be set with reference to the coasting test or the recommended scheme of driving resistance coefficient specified in GB/T 27840.
6.3.3.2 The passenger mass and loading requirements shall be carried out in accordance with the relevant regulations of GB/T 12534.
Note: For semi-trailer tractors, the maximum mass in this standard refers to the maximum mass of automobile trains.
6.3.4 Tire pressure
Before the test, the tire pressure shall be set to the pressure value when the vehicle establishes the road resistance coefficient on the chassis dynamometer, and shall not exceed the manufacturer's specified value range.
6.3.5 Shifting
6.3.5.1 The driver shall achieve the corresponding relationship between the vehicle speed and the time specified for the driving cycle by using the appropriate operation of the accelerator pedal or/and accurately selecting the shifting speed. It shall be avoided that the vehicle speed changes more slowly than the theoretical speed, or there is excessive acceleration pedal disturbance, so as not to cause the invalidity of the test.
6.3.5.2 The process shall be smoothly accelerated according to the suggestions of the automobile manufacturer. For manual gearbox, the driver shall complete the shifting process in the shortest time. If failing to accelerate at the specified speed, the vehicle shall travel at the maximum accelerator pedal until the speed meets the theoretical speed requirement.
6.3.6 Tolerance
6.3.6.1 If the maximum speed of the vehicle is not less than that of the CHTC, the test shall be carried out according to the test cycle specified in 5.1, and the speed and time tolerances of the test cycle shall meet the requirements of the tolerances and reference curves given in Figure 1. Each point in Figure 1 gives a speed tolerance of ± 3 km/h and a time tolerance of ± 1 s. In each test cycle, the cumulative time allowed to exceed the tolerance range shall not exceed 15 s. The total time exceeding tolerances shall be indicated in the test report.
Figure 1 Reference curves and tolerances
6.3.6.2 If the maximum speed of the vehicle is less than the maximum speed of the CHTC, the test shall be carried out according to the test cycle specified in 5.2. The speed tolerances, time tolerances and cumulative time beyond the tolerance range of the test cycle shall be given in accordance with the regulations of 6.3.6.1. For the part exceeding the maximum speed of the vehicle, the accelerator pedal shall be pressed to the bottom, allowing the actual speed of the vehicle to exceed the upper limit of speed tolerance, but meeting the requirements of the lower limit of speed tolerance.
6.3.6.3 If the vehicle cannot meet the tolerance requirements of the test cycle, the automobile manufacturer may apply to the competent department for the vehicle model to be a special vehicle model and provide relevant information.
6.3.7 Setting for other vehicles
If the vehicle has the function of regenerative braking, the control strategy same with the actual vehicle shall be adopted during the test. If the vehicle is equipped with an antilock brake system (ABS), a traction control system (TCS) or an electronic braking system (EBS), and is tested on a single-axis drive chassis dynamometer, the above three systems may mistake the non-rotating wheel that is not placed on the hub as a faulty system. In such case, shielding shall be performed for normal system operation.
6.3.8 Test fuel
6.3.8.1 The test fuel shall meet the requirements of the automobile manufacturer by using the benchmark fuel in accordance with the requirements of Annex K in GB 18352.6-2016 or the commercially available vehicle fuel in accordance with relevant national standards.
6.3.8.2 The density of fuel is measured in accordance with GB/T 1884.
6.3.8.3 If the carbon balance method is used for calculating fuel consumption, the hydrogen-carbon ratios of gasoline and diesel are assumed to be 1.85 and 1.86 respectively.
6.4 Failure of REESS
If REESS is damaged, or the energy storage capacity of REESS is lower than the value specified by the automobile manufacturer, the REESS shall be regarded as invalid, and shall be subject to repairing, replacing and balancing as well as re-testing.
6.5 Measurement of coasting resistance and technical specifications of chassis dynamometer
The measurement of coasting resistance and the technical conditions of chassis dynamometer shall conform to the relevant requirements of GB/T 27840.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Calculation method for net energy change (NEC)
4.1 General requirements
4.2 Determination of NEC
4.3 Determination of NEC relative change
5 Test cycle
6 Test preparation
6.1 Test conditions
6.2 Pre-collection of vehicle data
6.3 Vehicle conditions
6.4 Failure of REESS
6.5 Measurement of coasting resistance and technical specifications of chassis dynamometer
6.6 Testing equipment
7 Test procedures
7.1 Start-up and pre-operation of vehicle propulsion system
7.2 Test flow
7.3 Test procedure for not off-vehicle-chargeable hybrid electric vehicles (NOVC-HEV)
7.4 Test procedure for off-vehicle-chargeable hybrid electric vehicle (OVC-HEV)
8 Data record and result
8.1 Environment data
8.2 Fuel density
8.3 SOC, traction battery voltage or ultracapacitor voltage
8.4 Driving distance
8.5 Fuel consumption
8.6 NEC calculation
8.7 Test results
8.8 CO2 emissions
9 Test report
Annex A (Information) Examples of determination procedure for NEC relative variation and SOC correction procedure
Annex B (Normative) Parameter list of test sample car
Annex C (Normative) OVC-HEV battery electric utility factor (UF)
Annex D (Information) Converted fuel consumption
Bibliography
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization — Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 19754-2015 Test methods for energy consumption of light-duty hybrid electric vehicles. In addition to structural adjustment and editorial changes, the following main technical changes have been made with respect to GB/T 19754-2015:
a) The scope has been modified, and regulations for inapplicable model and reference model have been added (see Clause 1; Clause 1 of 2015 edition);
b) Terms and definitions of ultracapacitor state of charge, net energy change, propulsion energy, propulsion system, regenerative braking, total fuel energy, total fuel propulsion energy and total cycle propulsion energy have been deleted (see 3.1 ~ 3.8 of 2015 edition);
c) The determination method for NEC relative change has been modified (see 4.3; 4.3 of 2015 edition);
d) The test cycle has been modified from CCBC and C-WTVC to China heavy-duty commercial vehicle test cycle (CHTC), and the correction method of the test cycle when the maximum speed of the vehicle is less than that of CHTC has been added (see Clause 5, Clause 5 of 2015 edition);
e) The test conditions have been modified, the ambient temperature requirements for road tests deleted, and the ambient temperature requirements for chassis dynamometer tests modified (see 6.1; 6.1 in 2015 edition);
f) The tolerance requirements for test cycles have been modified, the requirement that the cumulative time exceeding the tolerance range for each test cycle shall not exceed 15 s has been added (see 6.3.6; 6.3.6 in 2015 edition);
g) The requirements for test fuels have been added, and vehicle test preparation and pretreatment removed (see 6.3.8; 6.3.8 of 2015 edition);
h) The measurement of coasting resistance and the technical conditions of chassis dynamometer have been modified, and other relevant documents instead of the content of this document quoted (see 6.5; 6.5 and 6.6.2 of 2015 edition);
i) The test equipment has been modified, and equipment requirements for measuring natural gas added (see 5.2; 5.2 of 2015 edition);
j) The test flow has been added (see 7.2);
k) The requirements of vehicle immersion test between test cycles from 15 min to no more than 30 min (see 7.3.2, 7.4.2.1.4, 7.4.3.1.2; 7.3.3 of 2015 edition);
l) The pre-set of REESS has been modified (see 7.4.1; 7.4.1 of 2015 edition);
m) The test methods for battery electric driving range stage, REESS energy adjustment stage and electric energy balance stage have been modified, and the test methods of battery electric driving range stage modified from constant velocity method to working condition method (see 7.4.2.3 ~ 7.4.2.5; 7.4.2.3 ~ 7.4.2.5 of 2015 edition);
n) Charging and electricity measurement of the vehicle after the test has been added (see 7.4.2.6);
o) The carbon balance method has been added to measure fuel consumption (see 8.5);
p) Judging conditions for effective test have been modified (see 8.7.2; 8.7.2 of 2015 edition);
q) The calculation method of test results in the battery electric driving range stage, REESS energy adjustment stage and electric energy balance stage have been modified (see 8.7.3.1.2 ~ 8.7.3.1.4; 8.7.3.1.2 ~ 8.7.3.1.4 of 2015 edition);
r) The comprehensive vehicle energy consumption results have been added (see 8.7.3.1.5 and 8.7.3.2.3);
s) The calculation method for converted fuel consumption has been added (see 8.7.3.1.6, 8.7.3.2.4 and Annex D);
t) The calculation method of CO2 emissions has been added (see 8.8);
u) Requirements for test validity have been deleted (8.8 of 2015 edition);
v) The calculation method for the battery electric utility factor has been added (see Annex C);
w) The bus cycle data of typical cities in China and the driving cycle data and instructions of heavy-duty vehicles in the United States have been deleted (see Annexes B ~ D of 2015 edition).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by the Ministry of Industry and Information Technology of the People's Republic of China.
This standard is under the jurisdiction of the National Technical Committee of Auto Standardization (SAC/TC 114).
This document was issued in 2005 as first edition, its first revision was issued in 2015, and this is the second revision.
Test methods for energy consumption of heavy-duty hybrid electric vehicles
1 Scope
This standard specifies the test method for energy consumption of heavy-duty hybrid electric vehicles on chassis dynamometers.
This document is applicable to hybrid electric vehicles with a maximum total mass exceeding 3,500kg, including trucks, semi-trailer tractors, buses, dump trucks and city buses. The relevant measurement methods of dump trucks may be referred for concrete mixer trucks, and the relevant measurement methods of trucks for other special transport vehicles.
This standard is applicable to vehicles driven by gasoline or diesel oil as well as vehicles driven by other fuels.
This standard does not apply to special operation vehicles, including van-type special operation vehicles, tank-type special operation vehicles, special dump operation vehicles, warehouse-gate special operation vehicles, lifting special operation vehicles and specially-structured special operation vehicles.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1884 Crude petroleum and liquid petroleum products — Laboratory determination of density — Hydrometer method
GB/T 3730.1 Motor vehicles and trailers — Types — Terms and definitions
GB/T 12534 Motor vehicles — General rules of road test method
GB/T 15089 Classification of power-driven vehicles and trailers
GB 17691-2018 Limits and measurement methods for emissions from diesel fuelled heavy-duty vehicles (CHINA VI)
GB 18352.6-2016 Limits and measurement methods for emissions from light-duty vehicles
GB/T 19596 Terminology of electric vehicles
GB/T 27840 Fuel consumption test methods for heavy-duty commercial vehicles
GB/T 38146.2-2019 China automotive test cycle — Part 2: Heavy-duty commercial vehicles
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 3730.1, GB/T 15089, GB/T 19596 and GB/T 38146.2-2019 apply.
4 Calculation method for net energy change (NEC)
4.1 General requirements
The energy change of the rechargeable electric energy storage system (REESS) shall be monitored during the vehicle movement and test process.
4.2 Determination of NEC
4.2.1 NEC of traction battery
The NEC of the traction battery may be calculated by Formulae (1), (2) and (3):
NEC＝k × ∫Pdt (1)
P＝k1 × U×I (2)
(3)
where,
NEC——the net energy change, kWh;
k——the unit conversion factor, 10-3, kW/W;
P——the discharge power of the traction battery, W;
t——time, s;
k1——the unit conversion factor, 3,600-1, h/s;
U——the terminal voltage of the traction battery, V;
I——the terminal current of the traction battery, A;
ηc——the charging electricity efficiency of traction battery;
Ic——the current input to the traction battery bus, A;
Id——the current output from the traction battery bus, A;
ηd——the discharging electricity efficiency of the traction battery.
See A.1 in Annex for the values of the electricity efficiency of charging and discharging.
4.2.2 NEC for ultracapacitor
See Formula (4) for the calculation of NEC for ultracapacitor:
(4)
where,
k2——the unit conversion factor, 3,600,000-1, kWh/Ws;
C——the rated capacity of the ultracapacitor, F;
Ue——the voltage of the ultracapacitor bus at the ending of the test cycle, V;
Ub——the voltage of the ultracapacitor bus at the beginning of the test cycle, V.
4.3 Determination of NEC relative change
NEC relative change is defined as the ratio of the NEC converted to the wheel to the total cycle propulsion energy, and is calculated by Formula (5):
(5)
where,
NECre——the NEC relative change;
ηtr——the transmission efficiency, with recommended value of 83%;
Ecycle——the total cycle propulsion energy (in kWh), which is calculated through the unit conversion factor k2 of Formula (4) according to the relevant regulations of Attachment CE.5 of GB 18352.6-2016.
According to the suggestions of the automobile manufacturer and confirmed by the inspection body, ηtr may be replaced by the recommended value of the automobile manufacturer, at which time ηt shall be indicated in the test report.
5 Test cycle
5.1 The fuel consumption of vehicles is measured according to China heavy-duty commercial vehicle test cycle (CHTC) specified in Annex A of GB/T 38146.2-2019. Among them, the city buses adopt CHTC-B test cycles; buses (excluding city buses) adopt CHTC-C test cycle; trucks (excluding dump trucks) adopt CHTC-LT (GVW ≤ 5,500 kg) or CHTC-HT (GVW > 5,500 kg) test cycles; the dump trucks adopt CHTC-D test cycles; and the semi-trailer tractors adopt CHTC-TT test cycles.
5.2 If the maximum speed of the vehicle is less than that of the CLTC, the test cycle shall be corrected in accordance with the regulations of Attachment CA.5 in GB 18352.6-2016 if the target speed is greater than the maximum speed of the vehicle.
6 Test preparation
6.1 Test conditions
6.1.1 Recommended ambient temperature is (23 ± 5)°C. The ambient temperature range may be relaxed to 5°C～35°C upon recommended by the automobile manufacturer and confirmed by the inspection body. During the test and at the beginning and end of the test, the temperature shall not exceed this range, and the actual ambient temperature shall be indicated in the test report.
6.1.2 The test site shall be equipped with traction battery ventilation and cooling devices, flywheel guard, anti-high pressure safety device, and other necessary safety protection facilities. During the test, a fixed speed fan may be used to direct cooling air to the vehicle to ensure that the engine working temperature meets the requirements of the manufacturer. The fan may only work when the vehicle is running, and shall be turned off when the vehicle stops.
6.2 Pre-collection of vehicle data
6.2.1 Prior to the test, the vehicle parameters shall be recorded in detail in accordance with the content of Annex B.
6.2.2 Any content that differs from the basic program, such as a test vehicle runs in a mode different from hybrid electric vehicles, shall be fully recorded for subsequent test to reproduce the test.
6.3 Vehicle conditions
6.3.1 Running-in
Before the test, the vehicle shall travel in accordance with the requirements of the automobile manufacturer, or run for not exceeding 10,000 km.
6.3.2 Vehicle status
The vehicle status shall be checked before the test:
——The performance of the test vehicle shall meet the requirements of the automobile manufacturer and be capable of running normally;
——The engine, motor and vehicle controls shall be adjusted according to the requirements of the automobile manufacturer;
——If the vehicle's cooling fan is temperature-controlled, it shall be kept in normal working condition, and the air conditioning system in the passenger compartment shall be turned off.
6.3.3 Test vehicle load
6.3.3.1 For city buses, the test shall be carried out at 65% of the maximum design loading mass. The setting of road load shall refer to the coasting test specified in GB/T 27840, and shall be based on the suggestions of the automobile manufacturer and confirmed by the inspection body. The road load may also be set based on the interpolation calculation of the recommended scheme of driving resistance coefficient specified in GB/T 27840, or subjected to testing under the state of maximum mass, and the setting of road load may refer to the coasting test or recommended scheme of driving resistance coefficient specified in GB/T 27840; for other heavy-duty commercial vehicles, the test shall be carried out at the state of maximum mass, and the road load shall be set with reference to the coasting test or the recommended scheme of driving resistance coefficient specified in GB/T 27840.
6.3.3.2 The passenger mass and loading requirements shall be carried out in accordance with the relevant regulations of GB/T 12534.
Note: For semi-trailer tractors, the maximum mass in this standard refers to the maximum mass of automobile trains.
6.3.4 Tire pressure
Before the test, the tire pressure shall be set to the pressure value when the vehicle establishes the road resistance coefficient on the chassis dynamometer, and shall not exceed the manufacturer's specified value range.
6.3.5 Shifting
6.3.5.1 The driver shall achieve the corresponding relationship between the vehicle speed and the time specified for the driving cycle by using the appropriate operation of the accelerator pedal or/and accurately selecting the shifting speed. It shall be avoided that the vehicle speed changes more slowly than the theoretical speed, or there is excessive acceleration pedal disturbance, so as not to cause the invalidity of the test.
6.3.5.2 The process shall be smoothly accelerated according to the suggestions of the automobile manufacturer. For manual gearbox, the driver shall complete the shifting process in the shortest time. If failing to accelerate at the specified speed, the vehicle shall travel at the maximum accelerator pedal until the speed meets the theoretical speed requirement.
6.3.6 Tolerance
6.3.6.1 If the maximum speed of the vehicle is not less than that of the CHTC, the test shall be carried out according to the test cycle specified in 5.1, and the speed and time tolerances of the test cycle shall meet the requirements of the tolerances and reference curves given in Figure 1. Each point in Figure 1 gives a speed tolerance of ± 3 km/h and a time tolerance of ± 1 s. In each test cycle, the cumulative time allowed to exceed the tolerance range shall not exceed 15 s. The total time exceeding tolerances shall be indicated in the test report.
Figure 1 Reference curves and tolerances
6.3.6.2 If the maximum speed of the vehicle is less than the maximum speed of the CHTC, the test shall be carried out according to the test cycle specified in 5.2. The speed tolerances, time tolerances and cumulative time beyond the tolerance range of the test cycle shall be given in accordance with the regulations of 6.3.6.1. For the part exceeding the maximum speed of the vehicle, the accelerator pedal shall be pressed to the bottom, allowing the actual speed of the vehicle to exceed the upper limit of speed tolerance, but meeting the requirements of the lower limit of speed tolerance.
6.3.6.3 If the vehicle cannot meet the tolerance requirements of the test cycle, the automobile manufacturer may apply to the competent department for the vehicle model to be a special vehicle model and provide relevant information.
6.3.7 Setting for other vehicles
If the vehicle has the function of regenerative braking, the control strategy same with the actual vehicle shall be adopted during the test. If the vehicle is equipped with an antilock brake system (ABS), a traction control system (TCS) or an electronic braking system (EBS), and is tested on a single-axis drive chassis dynamometer, the above three systems may mistake the non-rotating wheel that is not placed on the hub as a faulty system. In such case, shielding shall be performed for normal system operation.
6.3.8 Test fuel
6.3.8.1 The test fuel shall meet the requirements of the automobile manufacturer by using the benchmark fuel in accordance with the requirements of Annex K in GB 18352.6-2016 or the commercially available vehicle fuel in accordance with relevant national standards.
6.3.8.2 The density of fuel is measured in accordance with GB/T 1884.
6.3.8.3 If the carbon balance method is used for calculating fuel consumption, the hydrogen-carbon ratios of gasoline and diesel are assumed to be 1.85 and 1.86 respectively.
6.4 Failure of REESS
If REESS is damaged, or the energy storage capacity of REESS is lower than the value specified by the automobile manufacturer, the REESS shall be regarded as invalid, and shall be subject to repairing, replacing and balancing as well as re-testing.
6.5 Measurement of coasting resistance and technical specifications of chassis dynamometer
The measurement of coasting resistance and the technical conditions of chassis dynamometer shall conform to the relevant requirements of GB/T 27840.
Contents of GB/T 19754-2021
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Calculation method for net energy change (NEC)
4.1 General requirements
4.2 Determination of NEC
4.3 Determination of NEC relative change
5 Test cycle
6 Test preparation
6.1 Test conditions
6.2 Pre-collection of vehicle data
6.3 Vehicle conditions
6.4 Failure of REESS
6.5 Measurement of coasting resistance and technical specifications of chassis dynamometer
6.6 Testing equipment
7 Test procedures
7.1 Start-up and pre-operation of vehicle propulsion system
7.2 Test flow
7.3 Test procedure for not off-vehicle-chargeable hybrid electric vehicles (NOVC-HEV)
7.4 Test procedure for off-vehicle-chargeable hybrid electric vehicle (OVC-HEV)
8 Data record and result
8.1 Environment data
8.2 Fuel density
8.3 SOC, traction battery voltage or ultracapacitor voltage
8.4 Driving distance
8.5 Fuel consumption
8.6 NEC calculation
8.7 Test results
8.8 CO2 emissions
9 Test report
Annex A (Information) Examples of determination procedure for NEC relative variation and SOC correction procedure
Annex B (Normative) Parameter list of test sample car
Annex C (Normative) OVC-HEV battery electric utility factor (UF)
Annex D (Information) Converted fuel consumption
Bibliography
