T/CSAE 44-2015Evaluation and test methods for regenerative braking energy recovery rate of pure electric passenger vehicle (English PDF)

3.1 Electric vehicle electric vehicle

Electric vehicles include pure electric, hybrid, plug-in hybrid (including extended program) and fuel cell electric vehicles (GB/T 19596-2004 3.1.1 definition)

3.2 Electric vehicle complete vehicle quality complete electric vehicle kerb mass

The whole vehicle kerb quality including the vehicle energy storage device (defined in GB/T 19596-2004 3.1.4.1).

3.3 Recyclable energy of electric vehicle

In the conditions of taxiing, braking, etc., the total amount of kinetic energy of the vehicle removes the energy remaining after the windage and the energy consumed by the rolling resistance.

3.4 Recyclable energy of electric vehicle

In the conditions of taxiing, braking, etc., the electric motor can be used to convert the recoverable energy of the electric vehicle into electric energy and stored in the energy storage device.

the amount.

3.5 Electric vehicle regenerative braking regenerative braking of electric vehicle

In the conditions of taxiing, braking, etc., the electric motor is used to convert the recoverable energy of the electric vehicle into electric energy, and is supplied to the energy storage device or His process of using electrical equipment.

3.6 Energy recovery of coasting mode

During the driving process, when the driver releases the throttle and does not step on the brake pedal, the motor converts the recoverable energy of the electric vehicle into electrical energy.

3.7 Braking energy recovery energy recovery of braking mode

During the driving process, when the driver releases the accelerator and depresses the brake pedal, the motor converts the electric vehicle's recoverable energy into electrical energy.

3.8 Regenerative braking energy recovery rate of the single mode

In one braking or taxiing, the energy recovered by the energy storage device accounts for the percentage of energy that can be recovered by the electric vehicle.

3.9 Regenerative braking energy recovery rate of the cycle mode

In a cycle, the energy recovered by the energy storage device accounts for the percentage of energy that can be recovered by the electric vehicle.

4.1 Evaluation indicators

4.1.1 Regeneration braking energy recovery rate under single operating conditions

4.1.2 Recycling energy recovery rate under cyclic conditions

5.1 Test conditions and status requirements

5.1.1 Vehicle status requirements

The test vehicle shall be loaded according to the technical requirements of each test.

At ambient temperature, the test vehicle tire pressure should be in accordance with the vehicle manufacturer's regulations.

The viscosity of the lubricating oil for mechanical moving parts should meet the manufacturer's specifications.

The lighting, signalling, and auxiliary electrical equipment on the vehicle should be turned off unless the test and the vehicle are running during the day.

begging.

Except for the drive application, all energy storage systems should be filled to the maximum values specified by the manufacturer (electrical, hydraulic, pneumatic, etc.).

The test driver shall operate the energy storage device at normal operating temperatures in accordance with the operating procedures recommended by the vehicle manufacturer.

Before the test, the test vehicle should travel at least 300km with the energy storage device installed on the vehicle. (GB/T 18386-2005 4.3.2 definition)

5.1.2 Test quality of electric vehicles

The sum of the quality of the whole vehicle and the additional quality required for the test (defined in GB/T 19596-2004 3.1.4.2).

The additional mass is (defined in GB/T 18386-2005 3.2).

If the maximum allowable loading mass is less than or equal to 180 kg, the mass is the maximum allowable loading quality;

If the maximum allowable loading mass is greater than 180kg but less than 360kg, the mass is 180kg;

If the maximum allowable loading mass is greater than 360 kg, the mass is half of the maximum allowable loading mass.

5.1.3 Status requirements for electric vehicle regenerative braking system

A vehicle regenerative braking system includes a friction braking system and an electric braking system. Its status requirements should meet the requirements of GB/T 21670-2008 Relevant content for friction braking systems and electric regenerative braking systems. (GB/T 21670-2008 4, 5 and Appendix D definition)

5.1.4 Chassis dynamometer test conditions

The test conditions of the chassis dynamometer shall meet the relevant content specified in JJF1221-2009 and be calibrated according to its contents.

5.1.5 Road test conditions

5.1.5.1 The quality status of the vehicle shall comply with the corresponding provisions of the various tests and shall be stated in the test report.

5.1.5.2 All types of tests shall be carried out according to the corresponding prescribed speed; if the maximum designed vehicle speed of the vehicle is lower than the test specified speed, the maximum shall be Design the speed of the vehicle for testing.

5.1.5.3 Unless otherwise specified, the test pavement shall have good adhesion properties.

5.1.5.4 The test shall be carried out with a wind speed of less than 3 m/s without affecting the test results.

5.1.5.5 At the beginning of the test, the tyre shall be cold and at the specified pressure corresponding to the actual load of the wheel when the vehicle is stationary.

5.1.5.6 For vehicles driven by motors that are wholly or partially connected to the wheels, all tests shall be carried out under the conditions of motor combination.

Row.

5.1.5.7 For vehicles as described in 5.1.5.6, if they are equipped with a regenerative braking system, they shall be as specified in 5.6.3.2.2 of GB 21670-2008.

Low-adhesion coefficient on the road surface according to the provisions of GB 21670-2008 5.1.4.3.1 vehicle state test; shift or release the accelerator pedal the vehicle status should not be affected.

5.1.5.8 If the energy storage device (or auxiliary energy storage device) used for regenerative braking of electric vehicles can only be charged from an independent external charging system Electric, the average state of charge of the energy storage device in the braking performance test shall not exceed the brake loss specified in GB 21670-2008 4.2.20.5 5% of the state of charge at the time of the alarm.

If an alarm occurs, the energy storage device can be charged during the test to keep its state of charge within the specified range.

If a road test is carried out, the test conditions shall comply with the requirements of GB/T 12534.

5.1.6 Battery Status Requirements

The state of charge of the energy storage device shall be determined in accordance with the method specified in Appendix B of GB 21670-2008.

The charge and discharge requirements of the energy storage device shall meet the charging procedures specified in GB/T 18385 and the discharge procedures specified in GB/T 18386.

5.1.7 Motor Status Requirements

The state requirements of the motor should meet the relevant content of the electric regenerative braking system specified in GB/T 21670-2008. (GB/T 21670-2008 4, 5 and Appendix D definition)

5.1.8 Ambient temperature conditions

For indoor and outdoor tests, the temperature range of the battery cells must be maintained between (15 and 32 ゚C) at ambient temperature.

5.2 Test methods and test items for regenerative braking of electric vehicles

5.2.1 General

The following method describes a chassis dynamometer and road test method for regenerative braking energy recovery in single and cyclic conditions.

5.2.2 Test parameters

The main equipment includes vehicle data acquisition system, temperature measuring instrument, air pressure measuring instrument, wind speed measuring instrument, voltage sensor and current.

Sensors, counterweights, stopwatches, etc. All equipment used in the test must be calibrated.

Table 1 specifies the parameters, units and accuracy of the measurements.

Table 1 Measurement parameters, units and accuracy

Measurement parameter unit accuracy resolution Temperature °C ±1 1 Air pressure kPa ±1 1 Wind speed km/h ±1 1 Tire pressure kPa ±5 1 Time s ±0.1 0.1 Speed km/h ±1 1 Mass Kg ±0.25% 1 Voltage V ±0.1% FS 0.1 Current A ±1% FS 1

5.2.3 Tolerance

The speed tolerances and time tolerances in cycles and single conditions should meet the definition of 4.8.2 of GB 18386-2005.

5.2.4 Standards for ending the test

5.2.4.1 Standards for end-of-cycle test

- When the vehicle instrument gives the driver's parking instruction, the test should be stopped;

--For pure electric passenger cars, drive at a constant speed of 60Km/h at a constant speed of 30Km, at which time the SOC of the battery is cycled.

The initial conditions of the test, and then complete four consecutive complete world light vehicle test cycles in accordance with the World Light Vehicle Test Procedure (WLTP) Ring (WLTC ).

5.2.4.2 Standards for the end of single operation test

- When the vehicle instrument gives the driver's parking instruction, the test should be stopped;

-- Complete 4 effective and complete single-case tests for each item.

5.2.5 Validity of the test

- When the cycle condition test is conducted, the actual vehicle speed exceeds the allowable range of the theoretical vehicle speed tolerance, and the time exceeding the vehicle speed deviation in a single time is greater than 1s, or the cumulative time of the cycle exceeding the deviation of the vehicle speed is greater than 4s, the test is considered invalid;

- In the single-braking condition test, the allowable range of the theoretical brake pedal force tolerance corresponding to different braking strengths is exceeded.

Invalid;

5.2.6 Charge and discharge devices

5.2.6.1 General

The following energy storage devices are mainly charged and discharged for pure electric passenger cars.

5.2.6.2 Discharge of energy storage device

First, the test vehicle travels at a steady speed of 70% ± 5% of the 30-minute maximum speed (on the circular runway or chassis dynamometer).

Discharge the energy storage device of the vehicle.

- the speed cannot reach 65% of the maximum speed of 30 minutes, or - The instrument installed in the vehicle by the vehicle manufacturer reminds the driver to stop the vehicle.

5.2.6.3 Charging of energy storage devices

The vehicle charges the energy storage device according to the charging procedure specified in GB/T 18385, so that the energy storage device is fully charged.

5.2.7 Chassis Dynamometer Test Method

5.2.7.1 Recycling braking energy recovery in cyclic conditions

Since the electric vehicle is equipped with a brake anti-lock braking system or a vehicle stability control system, it is tested on a two-drive chassis dynamometer.

During the inspection, these control systems of the car may misinterpret the wheels that are not placed on the chassis dynamometer and do not rotate. Such as hair such a phenomenon must be corrected for the brake anti-lock brake system or the wheel speed sensor of the vehicle stability control system (the wheel of the drive wheel) in order to avoid the above situation, it is recommended to use a four-wheel drive chassis dynamometer for testing.

5.2.7.2 Chassis Dynamometer Settings

Before the test, the chassis dynamometer shall set the vehicle road load according to the provisions in Appendix C of GB 18352.1-2001, and measure it in the chassis.

Simulated on the machine.

5.2.7.3 Cycle test

Test according to the cycle conditions specified in Appendix A. If the test of 5.2.5 occurs, this test is invalid. At least 4 Sub-effective cycle test.

5.2.8 Road test method

5.2.8.1 Single working condition test

Test according to the working conditions specified in Appendix B and D. If the test of 5.2.5 occurs, this test is invalid. At least complete 4 valid single-case test.

5.2.9 Calculation method

5.2.9.1 Energy recovered by electric vehicles

Chgchgchg dtIUEN (1) where. chg EN Energy recovered for regenerative braking of electric vehicles, kWh;

. unit conversion factor) ( 610 * 6.31 ;

chgU. instantaneous value of the voltage output of the DC inverter of the motor inverter, V;

chgI. instantaneous value of current output at the DC output of the motor inverter, A;

1t. the start time of the motor feedback work;

2t. the end time of the motor feedback work;

. For the charging efficiency of the battery, refer to Appendix C.

5.2.9.2 Electric vehicles can recover energy

Where. kEN is the recoverable energy of electric vehicles, kWh;

testM. car test quality, Kg;

1V. the initial speed of braking, Km/h;

2V. speed at the end of braking, Km/h;

V. speed during braking, Km/h;

A . air density, 1.205kg/m3;

DC. drag coefficient, refer to Appendix C;

A. Windward area, refer to Appendix C;

Rf . rolling resistance coefficient, refer to Appendix C;

g . gravity acceleration, 9.81 m/s2.

5.2.9.3 Regenerative braking energy recovery rate

According to formulas (1) and (2), we can get.

Where. regC is the regenerative braking energy recovery rate.

5.2.9.4 Regeneration braking energy recovery rate under single operating conditions

5.2.9.4.1 Sliding brake single-recovery regenerative braking energy recovery rate

(i=1,2,3,4) (4)

. the recovery rate of regenerative braking for single-time operation of taxi brake;

. single-slip brake, single-time sliding brake in maximum regenerative braking energy recovery mode Regenerative braking energy recovery rate under working conditions.

5.2.9.4.2 0.3g brake single-time regenerative braking energy recovery rate (i=1,2,3,4) (5) . 0.3g brake single-time regenerative braking energy recovery rate;

. The i-th 0.3g brake single-time regenerative braking energy recovery rate.

5.2.9.4.3 Regeneration braking energy recovery rate under single operating conditions

. Regeneration braking energy recovery rate in a single operating condition.

5.2.9.5 Recycled braking energy recovery rate under cyclic conditions

Where. jWLTC regC __ . regenerative braking energy recovery rate of the jth WLTC cycle condition;

ichgEN _ . energy recovered by the ith single-brake electric vehicle in the WLTC cycle condition;

ikEN _ . The ith single-brake electric vehicle can recover energy in the WLTC cycle.

aveWLTC cylregC ___ . WLTC cycle condition regenerative braking energy recovery.

5.2.10 Test project

5.2.10.1 Chassis Dynamometer Test Project

5.2.10.1.1 Taxi test project

Table 2 Table of taxi test items

Brake pedal accelerator pedal initial speed vehicle load test number SOC initial value car gear Off Off If (Vmax < 120) V initial velocity = Umax Half load 4 See Appendix D Maximum energy recovery Mode is in the position Else V initial speed = 120km/h

5.2.10.1.2 Cycle condition test project

Table 3 Cycle condition test item list

Cycling condition road surface attached ambient temperature vehicle load test number SOC initial value car gear WLTC high room temperature half load reference 5.2.4.1 reference 5.2.4.1 D file

5.2.10.2 Road test project

5.2.10.2.1 Road test with a braking strength of 0.3g

Table 4 Road test with a braking strength of 0.3g

Brake pedal pavement attached initial vehicle speed vehicle load test number SOC initial value car gear on high If (Vmax < 120) V initial velocity = Umax Else V initial velocity = 120km/h V Initial speed = 120Km/h Half load 4 Refer to Appendix DD file Appendix A (normative appendix) Test driving conditions A.1 Scope this appendix describes the WLTC test cycle and gives the baseline curve used for the test.

A.2 Test cycle

A.2.1 For electric vehicles, WLTC cycle conditions are required, as shown in Figure A.1.

Figure A.1 Test cycle conditions

The test cycle statistics recommended by this standard are detailed in Table A.1.

Table A.1 WLTC cycle

cycle

frequency

travel

time

travel

distance

average

Speed

highest

Speed

highest

Acceleration

maximum

decrease speed

parking

time

brake

frequency

parking

percentage

23.2

46.4

Km/h

129.5

Km/h

1.67

m/s2

-1.50

m/s2

47 13%

Appendix B

(normative appendix) B.1 Scope this appendix describes the single braking conditions for road testing of electric vehicles.

B.2 Test preparation B.2.1 When performing the brake test, it is not appropriate to install the brake pedal limit device according to safety considerations, so it is necessary to drive the tester according to Experience applying the appropriate braking force.

B.2.2 Before the brake test, the driving tester uses the pedal force sensor and the deceleration signal detected by the data acquisition system to calibrate the pedal the relationship between the plate force and the braking deceleration, and find out the pedal force corresponding to the braking deceleration required in the road test. The method is generally adopted.

The deceleration is 0.3±0.02g, the corresponding brake pedal force is optimal, and the error of the brake pedal force is ±2N, and the time tolerance is ±1s.

B.3 Test procedure

The road test for regenerative braking energy recovery of electric vehicles in single-time conditions must meet the relevant definitions in GB/T 21670-2008.

Appendix C

(informative appendix) Electric vehicle related parameters the relevant parameters of electric vehicles (provided by the manufacturer) are shown in Table C.1.

C.1 Related parameters of electric vehicles Type value Wind resistance coefficient Rolling resistance coefficient Frontal area Battery charging efficiency Appendix D (informative appendix) D.1 Scope this appendix describes the initial values of the battery SOC for an electric vehicle taxi test and a 0.3g intensity single-cycle regenerative braking energy recovery.

D.2 Test preparation D.2.1 When the SOC power display on the dashboard of the electric vehicle is in the following range, the test can be performed. If n is even, then the body window is n/2±1 cells; if n is odd, the specific window is (n-1)/2±1 cells.

D.3 Test procedure

The electric vehicle regenerative braking energy recovery test must meet the relevant definitions in GB/T 21670-2008.