GB/T 19754-2021Test methods for energy consumption of heavy-duty hybrid electric vehicles (English PDF)

4.1 General Requirements

During vehicle movement and test, the energy change of the rechargeable energy storage system (REESS) shall be monitored.

4.2 Determination of NEC

4.2.1 NEC of power storage battery

NEC of power storage battery shall be calculated in accordance with Formula (1) ~ Formula (3).

4.2.2 NEC of super capacitor

NEC of super capacitor shall be calculated in accordance with Formula (4).

6.2 Pre-collection of Vehicle Data

6.2.1 Before the test, in accordance with the content of Appendix B, vehicle parameters shall be recorded in detail.

6.2.2 Any content that is different from the basic procedure, for example, the test vehicle is running in a different working mode than the hybrid electric vehicles, shall be completely recorded for the subsequent tests to reproduce the test process.

6.3 Vehicle Conditions

6.3.1 Run-in

Before the test, in accordance with the automobile manufacturer's stipulations, the vehicle shall be subject to run-in, or the run-in shall not exceed 10,000 km.

6.3.3 Load of test vehicle

6.3.3.1 For city buses, the test shall be carried out under the condition of 65% of the maximum design loading mass. The setting of the road load shall take the taxiing test specified in GB/T 27840 as a reference.

6.3.4 Tire pressure

Before the test starts, the tire pressure shall be set to the pressure value when the vehicle establishes the road resistance coefficient on the chassis dynamometer, and must not exceed the range specified by the automobile manufacturer.

6.3.5 Gear shift

6.3.5.1 The driver shall use the appropriate operation of the accelerator pedal or / and the accurate selection of the gear shift speed to achieve the speed-to-time correspondence specified in the test cycle.

6.3.6 Tolerances

6.3.6.1 If the maximum speed of the vehicle is not less than the maximum vehicle speed of CHTC, in accordance with the test cycle specified in 5.1, the test shall be performed.

6.3.7 Other vehicle settings

If the vehicle has the function of braking energy regeneration, the same control strategy as the actual vehicle shall be used during the test.

6.3.8 Test fuel

6.3.8.1 The test fuel shall comply with the stipulations of the automobile manufacturer, and adopt the benchmark fuel that complies with the requirements of Appendix K in

GB 18352.6-2016, or the commercially available vehicle fuel that complies with the stipulations of the relevant national standards.

6.3.8.2 In accordance with GB/T 1884, determine the fuel density. The test equipment and accuracy requirements are as follows.

7.1 Start-up and Pre-operation of Vehicle Drive System

7.1.1 This document recommends that the vehicle be tested for energy consumption with the air conditioner turned off. For other vehicle-mounted accessories that are not necessary during the normal operation of the vehicles, during the test, they shall be disconnected or shielded.

7.1.2 The drive system of the vehicle shall be activated in accordance with the starting procedure recommended in the user manual provided by the automobile manufacturer.

7.2 Test Process

The test process is shown in Figure 2.

7.3 Test Procedure of Non-External Rechargeable Hybrid Electric Vehicle

(NOVC-HEV)

7.3.1 REESS pre-setting

For NOVC-HEV, the vehicle REESS shall be in the state of charge (SOC) for normal use as specified by the automobile manufacturer, otherwise, in accordance with the automobile manufacturer's requirements, and through the mode of external charging or the use of vehicle-mounted engine, REESS shall be preset and adjusted to the SOC for normal use.

7.4.2 OVC-HEV test procedure including pure electric working mode

7.4.2.1 General requirements

7.4.2.1.1 OVC-HEV, which includes pure electric working mode, refers to a vehicle that can complete a test cycle in a pure electric working mode on the premise of satisfying 6.3.6.

7.4.2.1.4 Unless it is otherwise specified, vehicle immersion is allowed in each test cycle; the immersion time shall not exceed 30 min. During the vehicle immersion, the ignition lock shall be turned off; the hood shall be closed; the test bench fan shall be turned off; the brake pedal shall be released; the external power supply shall not be used for charging.

7.4.2.3 Pure electric driving range stage (Stage I)

7.4.2.3.1 The test shall be carried out in accordance with the test cycle specified in Chapter 5.

7.4.2.5 Electric energy balance operation stage (Stage III)

Adopt the test cycle specified in Chapter 5 to continuously carry out the test. In addition, in accordance with 4.3, calculate the relative change of NEC of each test cycle. After the (n2 + 1)th test cycle, when the absolute value of the relative change of NEC is not greater than 5% for two times, the condition for the end of Stage III test is reached.

7.4.3 OVC-HEV test procedure excluding pure electric working mode

7.4.3.2 Movement of vehicle

7.4.3.2.1 In the case where the parking location where the vehicle completes the charging is not in the same place as the test site, the vehicle is required to move to the test site at a constant speed of not more than 30 km/h; the maximum distance from the vehicle preset location to the test site must not exceed 3 km. Then, cut off the power supply and turn off the ignition lock to perform vehicle immersion. The immersion time shall not exceed 15 min.

7.4.3.3 REESS energy adjustment stage

In accordance with the stipulations of 7.4.2.4, perform the test.

7.4.3.4 Electric energy balance operation stage

In accordance with the stipulations of 7.4.2.5, perform the test.

7.4.3.5 Charge and electricity measurement

In accordance with the stipulations of 7.4.2.6, measure the power EAC charged from the external power supply and the charging time.

8.1 Environmental Data

Record the ambient temperature and atmospheric pressure at the beginning and the end of the test.

8.2 Fuel Density

Before the test starts, the fuel density shall be recorded.

8.6 NEC Calculation

In accordance with the relevant stipulations of 4.2, calculate the NEC of each test cycle and the total NEC of the vehicle.

8.7 Test Results

8.7.3 OVC-HEV test result

8.7.3.1 OVC-HEV including pure electric working mode

8.7.3.1.4, multiply the conversion factor a to calculate CO2 emission Comprehensive The result of fuel consumption determined in accordance with 8.7.3.1.5.1 or 8.7.3.2.3.1, multiply the conversion factor a to calculate CO2 emission