T/CSAE 76-2018Rapid evaluation and test methods for energy recovery effectiveness of regenerative braking for battery electric vehicles (English PDF)

3.1 Pure electric vehicle battery electric vehicle

A motor driven motor powered by electrical energy. The driving energy of the motor is derived from the vehicle rechargeable energy storage system.

Or other energy storage devices.

[GB/T 19596-2017, definition 3.1.1.1]

3.2 Rechargeable energy storage system rechargeable energy storage system (REESS)

An energy storage system that can be charged and provides electrical energy, such as batteries and capacitors.

[GB/T 18384.1-2015, definition 3.1] 2T/CSAE 76 -.2018

3.3 Regenerative braking regenerative braking

When the car is taxiing, slowing down or going downhill, the kinetic energy and potential energy during the driving process are converted or partially converted into vehicle-mounted rechargeable energy storage.

The braking energy of the system is stored up.

[GB/T 19596-2017, definition 3.1.3.1.2]

3.4 The energy of motor regeneration regenerated energy by the motor when the car is coasting, slowing down or going downhill, the motor works in the state of regeneration.

3.5 Vehicle recoverable energy recyclable energy of vehicle

When the car is taxiing, decelerating or going downhill, the total change in kinetic energy of the car removes air resistance, rolling resistance, slope resistance and vehicle interior.

The energy remaining after the energy consumed by the frictional resistance.

3.6 Energy recovery efficiency

An indicator reflecting the energy recovery level of the regenerative braking system, which can be used for braking energy recovery efficiency or regenerative braking for energy economy.

Contribution rate to evaluate.

Note. Rewrite QC/T 1089-2017, definition 3.5.

3.7 Brake energy recovery efficiency braking energy recovery efficiency

When a car taxis, decelerates, or goes downhill, the energy that the motor regenerates is a percentage of the vehicle's recoverable energy.

3.8 Contribution rate of energy economy

The energy recovered during car taxiing, deceleration or downhill, and then used in car operation accounts for the total consumption of the car during the entire driving process.

The percentage of energy.

4 Test method for energy recovery efficiency of regenerative braking of pure electric vehicles

4.1 General

The following method describes the test method for the energy recovery efficiency of regenerative braking of pure electric vehicles.

4.2 Test equipment

The test equipment includes a vehicle data acquisition system, a temperature measuring instrument, a voltage sensor, a current sensor, a counterweight device, and the like. in order to Use external equipment to measure the voltage and current of the rechargeable energy storage system and provide an appropriate, safe, accessible connection on the vehicle point. Table 1 specifies the parameters, units and accuracy of the test measurements.

3T/CSAE 76 -.2018

Table 1 Requirements for measurement parameters, units and accuracy

Measurement parameter unit accuracy resolution Time s ±0.1 0.1 Temperature °C ±1 1 Speed km/h ±1% 0.2 Mass kg ±0.5% 1 Voltage V ±0.1% FS 0.1 Current A ±0.1% FS 0.1

4.3 Test conditions

4.3.1 Vehicle conditions

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

Tires should be selected from the type required by the manufacturer as the original fitting, and the maximum test load and maximum test of the tire recommended by the manufacturer.

The tire inflation pressure corresponding to the speed is inflated. The viscosity of the lubricating oil for mechanical moving parts should meet the manufacturer's specifications.

The lighting, signalling, and ancillary equipment on the vehicle should be turned off unless required for testing and vehicle daytime operation.

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 power battery at normal operating temperatures in accordance with the operating procedures recommended by the vehicle manufacturer.

Before the test, the test vehicle shall be driven for at least 300km with a rechargeable energy storage system installed on the vehicle. [GB/T 18386-2017 4.3.2] at the beginning of the test, the tire should be cold and at a specified pressure corresponding to the actual load of the wheel when the vehicle is stationary. [GB 21670-2008 5.1.2.6]

4.3.2 Test quality of electric vehicles

The sum of the quality of the whole vehicle and the additional quality required for the test of the electric vehicle is 100kg. [GB/T 18386-2017 4.3.1]

4.3.3 Regenerative braking system status requirements

The vehicle regenerative braking system includes a friction braking system and an electric braking system, and the state of the regenerative braking system should meet GB 21670-2008 Relevant content for friction braking systems and electric regenerative braking systems as specified in 4, 5 and Appendix D. [T/CSAE 44-2015 5.1.3]

4.3.4 Chassis dynamometer test conditions

The test conditions of the chassis dynamometer shall meet the relevant content specified in JJF 1221 and be calibrated according to its contents. [T/CSAE 44-2015 5.1.4]

4.3.5 Road test conditions

4.3.5.1 The quality status of the vehicle shall comply with the corresponding provisions of the various tests and shall be stated in the test report. [GB 21670-2008 5.1.2.1] 4T/CSAE 76 -.2018

4.3.5.2 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, Test at the highest design speed. [GB 21670-2008 5.1.2.2]

4.3.5.3 Unless otherwise specified, the test pavement shall have good adhesion properties. [GB 21670-2008 5.1.2.4]

4.3.5.4 The test shall be carried out with a wind speed of less than 3 m/s without affecting the test results. [T/CSAE 44-2015 5.1.5.4]

4.3.5.5 For vehicles driven solely or partially by motors that are permanently connected to the wheels, all tests shall be in the condition of motor coupling Go on. [GB 21670-2008 5.1.8]

4.3.5.6 If a road test is carried out, the test conditions shall comply with the requirements of GB/T 12534. [T/CSAE 44-2015 5.1.5]

4.3.6 Battery Status Requirements

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

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

sequence. [T/CSAE 44-2015 5.1.6]

4.3.7 Motor Status Requirements

The state requirements of the motor should meet the requirements of GB 21670-2008 4, 5 and Appendix D for the electric regenerative braking system.

content. [T/CSAE 44-2015 5.1.7]

4.3.8 Ambient temperature conditions

Perform an outdoor test at an ambient temperature of (5 to 32) °C.

The indoor test was carried out at room temperature (20 to 30) °C. [GB/T 18386-2005 4.3.2]

4.4 Test methods

4.4.1 General

The same test procedure should be used to determine the contribution rate of braking energy recovery efficiency and energy economy.

4.4.2 Tolerance

The speed and time tolerances in the test cycle should meet the tolerances and datum curves given in Figure 1.

Description.

1--reference curve;

2--speed tolerance in kilometers per hour (km/h);

3--time tolerance in seconds (s)

Figure 1 datum curve and tolerance

Time/s

5T/CSAE 76 -.2018

Each point in Figure 1 gives a speed tolerance of ±2km/h and a time tolerance of ±1s.

In each drive cycle, the cumulative time allowed to exceed the tolerance range should not exceed 4 s. Excessive tolerances should be indicated in the test report Total time. [GB/T 18386-2017 4.4.2]

4.4.3 Standards for ending the test

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

-- Complete 4 consecutive complete cycle tests in accordance with the conditions specified in A.2 of Appendix A.

4.4.4 Validity of the test

When the cycle condition test is carried out on the chassis dynamometer, the actual vehicle speed exceeds the allowable range of the theoretical vehicle speed tolerance, and the vehicle speed deviation is exceeded in a single time.

The time is greater than 1 s, or the time when the cycle cumulatively exceeds the vehicle speed deviation is greater than 4 s, the test is considered invalid.

4.4.5 Chassis Dynamometer Test Method

4.4.5.1 For electric vehicles equipped with brake anti-lock braking system or vehicle stability control system, it is recommended to use four-wheel drive chassis test.

The machine is tested. [T/CSAE 44-2015 5.2.7.1]

4.4.5.2 Chassis Dynamometer Settings

Before the test, the chassis dynamometer shall set the vehicle road load according to the provisions in Appendix C of GB 18352.5-2013 and measure it at the chassis.

Simulated on the machine.

4.4.5.3 Perform the cycle test on the chassis dynamometer according to 5.4.7.

4.4.6 Road test method

Cycle test on the road according to 5.4.7.

4.4.7 Cycle test

The state of charge of the rechargeable energy storage device is adjusted to the vicinity of the intermediate value and tested according to the cycle conditions specified in Appendix A. If for the test of 5.4.4, the test is invalid. Perform 4 consecutive cycles of testing, averaging the results of valid test groups, as a result of the overall evaluation of the test. At least 3 effective cycle conditions tests must be completed.

If the test driver can select several operating modes (sports, comfort, economy, etc.) on the vehicle, then you should look for Find the best gear that matches the cycle speed reference speed curve. For vehicles with multiple glide regenerative braking strength modes, try the corresponding mode should be set before the test and the regenerative braking intensity mode should be recorded in the test report. In the 4 cycle conditions test, it is not allowed to change Variable regenerative braking strength mode.

4.4.8 Calculation of energy for motor regeneration

In the formula.

-- the energy of motor regeneration, in joules (J);

6T/CSAE 76 -.2018

- the last moment of the i-th deceleration process, in seconds (s);

- the starting time of the i-th deceleration process, in seconds (s);

-- the power battery terminal voltage at the jth sampling moment in the i-th regenerative braking process, in volts (V);

-- the bus current of the power battery at the jth sampling moment in the i-th regenerative braking process, in ampere (A);

-- Car acceleration in meters per square second (m/s2).

The sampling frequency of the sum is at least 0.1s, and at least one digit is reserved after the decimal point.

4.4.9 Calculation of recoverable energy of vehicles

In the formula.

-- Vehicle recoverable energy in joules (J);

-- vehicle test quality in kilograms (kg);

--Automobile rotation mass conversion factor, provided by the manufacturer;

- the starting speed of the i-th deceleration process, in meters per second (m/s);

- the last speed of the i-th deceleration process, in meters per second (m/s);

- the speed of the jth sampling moment in the i-th deceleration process, in meters per second (m/s);

A, B, C -- Vehicle taxiing coefficient, obtained by the manufacturer or the test station in accordance with the sliding method specified in GB 18352.

4.4.10 Calculation of braking energy recovery efficiency

In the formula.

-- Brake energy recovery efficiency.

4.4.11 Calculation of the contribution rate of energy economy

In the formula.

- the contribution rate of regenerative braking to energy economy;

-- The average charging Joule efficiency of the power battery is provided by the manufacturer;

-- The average discharge Joule efficiency of the power battery is provided by the manufacturer;

--The output energy of the power battery, in joules (J);

- the last moment of the discharge process of the pth power battery, in seconds (s);

- the starting time of the discharge process of the pth power battery, in seconds (s);

7T/CSAE 76 -.2018

-- the voltage of the power battery terminal at the jth sampling time in the p-th discharge, in volts (V);

-- The bus current of the power battery at the jth sampling time during the p-th discharge, in ampere (A).

The sampling frequency of the sum is at least 0.1s, and at least one digit is reserved after the decimal point.

8T/CSAE 76 -.2018

Appendix A

(normative appendix) Test driving conditions A.1 Scope this appendix describes the test cycle for a pure electric passenger car and gives the reference curve used for the test.

A.2 Test cycle

The test cycle can be specified by the user and described in the test report. It is recommended to use ECE-15 working conditions or Chinese working conditions in urban roads.

Driving conditions. The ECE-15 operating conditions are shown in Figure A.1 and Table A.1.

Table A.1 ECE-15 conditions

Operation sequence operation state condition sequence number acceleration m/s2 speed km/h operation time s working condition time s cumulative time s

1 Parking 1 0.00 0 11 11 11

2 Acceleration 2 1.04 0 ~ 15 4 4 15 3 constant speed 3 0.00 15 8 8 23

4 Deceleration 4 -0.83 15 ~ 0 5 5 28

5 Parking 5 0.00 0 21 21 49