Method for testing and evaluating driving condition efficiency of electric drive train of equivalent vehicle, electronic device, server, and computer readable storage medium

Abstract

SOLUTION: The present invention provides a method for testing and evaluating driving condition efficiency of an electric drive train of an equivalent vehicle, comprising at least one of: a step S1 for preparing before testing, and acquiring specifications required for a test; a step S2 for performing test bench adjustment and parameter setting based on the specifications required for the test acquired in the step S1; a step S3 for performing the test of driving condition efficiency and collecting test data; and a step S4 for testing and evaluating the driving condition efficiency based on the test data of the step S3.EFFECT: Beneficial effect of the present invention is that from a design perspective of electric drive train design, an output characteristic of the electric drive train can be correlated with an actual driving condition of a vehicle, and a method is beneficial to a research and development process such as performance parameters of the electric drive train, control strategy, prototype calibration.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the technical field of electric vehicles, and in particular to a method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle. [Background technology]

[0002] The power source of new energy vehicles is the electric drivetrain system, whose main function is to convert the electric energy supplied by the battery into mechanical energy to drive the vehicle, and the efficiency during the energy conversion process directly affects the vehicle's dynamic performance and driving range. Therefore, high rotation speed / torque ratio, high energy efficiency for high-voltage vehicle platforms have become the development trend of electric drivetrain products.

[0003] In the bench efficiency test of electric drivetrains, at this stage, it is common to show the efficiency in the form of a map diagram, specifically referring to GB / T18488.2 "Electric vehicle drive motor system Part 2: Test method" and T / CSAE143-2020 "Evaluation specification for integrated electric drivetrains of pure electric passenger vehicles". The test results of the efficiency map of electric drivetrains not only reflect the efficiency distribution results of the system at various rotation speeds and torques, but also reflect the output characteristics of the system, so they are widely used in system research and development tests.

[0004] However, the bench efficiency test method for electric drivetrains has certain limitations. On the one hand, while driving a vehicle, the driving conditions need to be changed frequently to match various road conditions. The existing bench test is limited to some steady equivalent driving conditions and cannot meet the complete driving condition test of equivalent vehicle operation. On the other hand, transient time-varying factors such as temperature rise and harmonic loss during the actual operation of the system are not taken into account, which is significantly different from the actual application scenario of the system. In addition, the bench efficiency results of electric drivetrains are limited to the efficiency at a certain steady-state constant speed point, the efficiency section, the percentage of high-efficiency zones, the highest efficiency point, etc., and are relatively poorly related to the test driving conditions of the vehicle.

[0005] In summary, for real-world driving scenarios, existing electric drivetrain efficiency tests lack correlation with the actual driving conditions of a vehicle, and a method for testing and evaluating the driving condition efficiency of an equivalent vehicle's electric drivetrain is urgently needed to improve the performance of electric drivetrain products and increase the range performance of the vehicle. Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above, the present invention aims to provide a method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle, so as to realize the driving condition efficiency testing and evaluation of the electric drivetrain. [Means for solving the problem]

[0007] In order to achieve the above objectives, the technical solution of the present invention is implemented as follows: A method for testing and evaluating driving condition efficiency of an electric drivetrain of an equivalent vehicle, comprising at least one of the following steps: S1: Prepare for the test and obtain the specifications required for the test. S2: Based on the specifications required for the test obtained in step S1, the test bench is adjusted and parameters are set. S3, Conduct operating condition efficiency tests and collect test data. S4. Test and evaluate the operating condition efficiency based on the test data of step S3.

[0008] Furthermore, in step S1, the parameters required for the test are as follows: A1, Electric drivetrain sample specifications including operating voltage, rotational speed / torque, and speed ratio; A2, specifically, the target vehicle specifications including passenger car specifications and commercial vehicle specifications, A3, includes bench equivalent vehicle specifications including drive type, vehicle weight, dynamic load radius, and tire radius.

[0009] Furthermore, step S2 is specifically as follows. B1, setting an equivalent resistance curve of a target vehicle type: According to the determined target vehicle type, the target vehicle type specifications are obtained, and a running equivalent resistance curve is set. B2, Determining the test operating conditions: including selecting the test operating conditions, setting the time-flow rotational speed / torque curve, and inputting the driver model. B3, Tuning and loading upper computer parameters: The sample control logic of the electric drivetrain is torque control, which is used to control acceleration and braking output.

[0010] Furthermore, in setting the equivalent running resistance curve of B1, maximum vehicle speed, acceleration performance, factors for starting on a slope, etc. are taken into consideration comprehensively, and the equivalent resistance curve takes the form of a linear function or a quadratic function.

[0011] Furthermore, in determining the operating conditions of B2, Test driving conditions include NEDC, WLTC and CLTC driving conditions. The driver model includes the start switch, accelerator pedal control, brake control, and gear selection. Time-flow rotational speed / torque curve configuration includes sample motorized and powered states for electric drivetrains.

[0012] Furthermore, step S3 is specifically as follows. First, a sample of the electric drivetrain will be tested according to the operating conditions set out in B2. Then, during the testing process, a collection device is used to collect and record electrical, mechanical, and environmental signals, the collected signals including current, voltage, rotational speed, torque, power supply end output, mechanical power at the dynamometer end, and sample temperature.

[0013] Furthermore, step S4 is specifically as follows. D1, collect test data according to step S3, and count and record the voltage, current, and power data at the power source end and the rotational speed, torque, and mechanical power data at the dynamometer end; D2, Evaluate the operating condition efficiency: Use the power rate comparison method or the cumulative energy method to calculate the operating condition efficiency η, specifically, The power rate comparison method is as shown in equation (1), which calculates the power output P at the power source based on the test time flow t. Supply-out The mechanical power P output by the sample electric drivetrain is included in the results. uut-out The aim is to calculate the ratio of

[0014]

number

[0015] The cumulative energy method calculates the output electrical energy E at the power source based on the test time flow t as shown in equation (2). Supply-out The mechanical energy E output by the sample electric drivetrain is included in the results uut-out The aim is to calculate the ratio of

[0016]

number

[0017] Furthermore, the solution discloses an electronic device including a processor and a memory communicatively connected to the processor and used for storing instructions executable by the processor, said processor being used for executing a method for testing and evaluating the driving conditions efficiency of an electric drivetrain of said equivalent vehicle.

[0018] Furthermore, the solution discloses a server including at least one processor and a memory communicatively connected to said processor, said memory storing instructions executable by said at least one processor, said instructions being executed by the processor such that said at least one processor performs the method for testing and evaluating driving conditions efficiency of an electric drivetrain of an equivalent vehicle as described in any one of claims 1 to 7.

[0019] Furthermore, the solution discloses a computer readable storage medium on which a computer program is stored, which, when said computer program is executed by a processor, realizes a method for testing and evaluating driving condition efficiency of an electric drivetrain of an equivalent vehicle. Effect of the Invention

[0020] Compared with existing technologies, the method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle according to the present invention has the following beneficial effects: (1) The method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle according to the present invention is, from the perspective of electric drivetrain design, that the driving condition efficiency testing method can correlate the output characteristics of the electric drivetrain with the actual driving conditions of the vehicle, which is beneficial to the research and development process of the performance parameters, control strategies, prototype calibration, etc. of the electric drivetrain; (2) From the perspective of vehicle development and design, the method for testing and evaluating the driving condition efficiency of the electric drivetrain of an equivalent vehicle according to the present invention can realize the calibration and optimization of the performance of the electric drivetrain product at the early stage of vehicle development, which is beneficial to accelerating the vehicle development cycle; (3) The method for testing and evaluating the driving condition efficiency of the electric drivetrain of an equivalent vehicle according to the present invention expands the bench efficiency test project from the perspective of testing and evaluating the electric drivetrain, and the obtained driving condition test results can realize the vehicle energy efficiency evaluation of various electric drivetrains, which is beneficial for the classification and evaluation of electric drivetrain products. [Brief description of the drawings]

[0021] [Figure 1] 1 is a flow chart of a method for testing and evaluating driving condition efficiency of an electric drivetrain of an equivalent vehicle. [Diagram 2] FIG. 2 is a structural block diagram of the operating condition efficiency system. [Diagram 3] FIG. 2 is an equivalent resistance curve diagram of a vehicle. [Figure 4] 1 is a speed / torque time flow curve under NEDC driving conditions. [Diagram 5] 1 is a curve of speed / torque time flow under CLTC operating conditions. [Figure 6] 1 is a cumulative energy curve of an efficiency test under NEDC driving conditions. [Figure 7] 1 is a cumulative energy curve of a CLTC operating condition efficiency test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] It should be noted that, unless there is a contradiction, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0023] The present invention will now be described in detail with reference to the drawings and examples.

[0024] The present invention is a method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle (abbreviated as method, see Figs. 1-7), which establishes a correlation between the efficiency of the electric drivetrain and the vehicle driving conditions through the equivalent test driving conditions, and realizes the testing and evaluation of the driving condition efficiency of the electric drivetrain. Figs. 1 and 2 are a principle flow chart of the method described in the invention and a structural block diagram of a test system, and the technical solution of the present invention will be described in detail below with reference to the drawings and specific implementation methods, which are not intended to limit the protection scope of the present application. In this embodiment, the following steps are specifically included:

[0025] Step 1: Pre-exam preparation.

[0026] In the above step 1.1, a test sample of the electric drivetrain is selected, and the basic specifications of the test sample are initially determined based on the nameplate label of the train sample, and the specifications are as shown in Table 1.

[0027] [Table 1]

[0028] In step 1.2, the vehicle type is selected and the drive mode of the vehicle type is determined. In this embodiment, the vehicle type is a normal sedan with a front-wheel drive system.

[0029] The above Step 1.3: Bench equivalent vehicle specifications and target vehicle specifications are shown in Table 2.

[0030] [Table 2]

[0031] Step 2: Adjust the test bench and set parameters.

[0032] In step 2.1, based on the control vehicle determined in step 1, collect the equivalent vehicle running resistance curve of the target vehicle based on the actual vehicle test, target the bench test of the electric drivetrain, and select the form of the equivalent vehicle running resistance curve taking into account the bench input parameters and the test driving conditions. In this embodiment, a quadratic function curve form is selected, and the equivalent resistance curve of the target vehicle in the actual vehicle experiment is as shown in Figure 3. The fitting formula of the equivalent resistance curve is as follows:

[0033]

number

[0034] where F is the equivalent vehicle running resistance and V is the actual measured speed.

[0035] In the above step 2.2, two test driving conditions, NEDC and CLTC, are selected in this embodiment, and start / stop, acceleration / deceleration, and rotational speed / torque switching are controlled by the driver model self-configured on the bench itself. The equivalent vehicle running resistance curves and the time flow curves of rotational speed / torque for the two test driving conditions set based on step 2.1 are shown in Figures 4 and 5.

[0036] In the above step 2.3, the test system structure under bench operation condition is as shown in Figure 2, where the sample control logic of the electric drivetrain is torque control, and the test upper computer makes negative feedback adjustment to the rotation speed by collecting the rotation speed / torque signal of the output end of the sample during the test process.

[0037] Step 3 above involves testing operating conditions and collecting data.

[0038] In step 3.1 above, the equivalent vehicle operating condition efficiency is tested for the selected sample of electric drivetrains according to the NEDC and CLTC test operating conditions selected in step 2.2.

[0039] In the above step 3.2, data collection uses a high-precision data collection device to collect and record electrical signals, mechanical signals, environmental signals, etc. The recording scale is a time scale, ensuring that the test data is collected and stored within the same time flow. The above electrical signals are collected using devices such as a power analyzer and an oscilloscope, and the electrical signals specifically include the power, voltage, current, etc. output from the power supply end. The mechanical signals include the rotational speed signal and torque signal output by the electric drivetrain sample and the mechanical power at the dynamometer end, where the rotational speed signal and torque signal can be collected by a rotational speed / torque sensor equipped on the bench. The environmental signals include the temperature and humidity of the test environment, the temperature during the test process of the electric drivetrain sample, etc.

[0040] Step 4: Test and evaluate operating conditions efficiency.

[0041] Collect test data according to step 4.1: step 3 above, count and record data such as voltage, current, power at the power supply end, count and record data such as rotational speed, torque, mechanical power at the dynamometer end, and count and record data such as rotational speed, torque, mechanical power at the dynamometer end.

[0042] Step 4.2 above: Analyze the calculation results and evaluation based on the operating condition efficiency of the test data. In this embodiment, the cumulative energy method is used to calculate the operating condition efficiency η, and the calculation method is as shown in Equation (2). Specifically, the output energy E at the power source based on the test time flow t is Supply-out The mechanical energy E output by the sample electric drivetrain is included in the results uut-out This can be interpreted as the percentage of

[0043] The above test results are shown in Figure 6 and Figure 7. The accumulated energy over time under NEDC operating conditions is shown in Table 3, which is the electrical energy accumulated at the power source end and the mechanical energy accumulated at the dynamometer end, respectively. Similarly, the test results of the accumulated energy over time under CLTC operating conditions are shown in Table 4. From the above results, the operating condition efficiency is obtained, which is shown in Table 5.

[0044] [Table 3]

[0045] [Table 4]

[0046] [Table 5]

[0047] Those skilled in the art can understand that the units and method steps of each example described in connection with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of both, and in the above description, the configurations and steps of each example are generally described according to their functions in order to clearly show the compatibility of the hardware and software. Whether these functions are performed by hardware or software depends on the design constraints of a specific application and technical solution. Those skilled in the art can implement the described functions using different methods for each specific application, but such implementations should not be considered as going beyond the scope of the present invention.

[0048] In some embodiments provided by the present application, the disclosed method and system can be implemented in other ways. For example, the division of the above units is only a kind of logical functional division, and in actual implementation, other division methods are also possible, for example, multiple units or components can be combined or integrated into another system, or some functions can be omitted or not performed. The above units may or may not be physically separated, and the parts displayed as units may or may not be physical units. That is, they may be located in one place or distributed across multiple network units. It should be understood that some or all of the units can be selected according to actual needs to achieve the objectives of the embodiments of the present invention.

[0049] Finally, it should be noted that the above embodiments are only used to describe the technical solutions of the present invention, and do not limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still understand that the technical solutions recorded in the above embodiments can be modified or some or all of the technical features can be replaced with equivalents, and these modifications or replacements do not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of each embodiment of the present invention, and all of them should be covered by the claims and description of the present invention.

[0050] The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. 1. A method for testing and evaluating driving condition efficiency of an electric drivetrain of an equivalent vehicle, comprising: Step S1: preparing for the test and acquiring specifications necessary for the test; Step S2: Adjusting the test bench and setting parameters based on the specifications required for the test obtained in step S1; Step S3 of conducting an operating condition efficiency test and collecting test data; At least one of a step S4 of testing and evaluating operating condition efficiency based on the test data of step S3; In step S2, specifically, B1. Set the equivalent resistance curve of the target vehicle model: According to the determined target vehicle model, obtain the target vehicle model specifications and set the running equivalent resistance curve; B2. Determining test operation conditions: including selecting test operation conditions, setting time flow rotation speed / torque curve, and inputting driver model; B3. Tuning and loading upper computer parameters: The sample control logic of the electric drivetrain is torque control, which is used to control the acceleration and braking output; Furthermore, in determining the operating conditions of B2, The test operating conditions include NEDC, WLTC and CLTC operating conditions; The driver model is configured by the test bench itself and includes the start switch, accelerator pedal control, brake control and gear selection. The time-flow rotational speed / torque curve configuration includes sample motorized and powered states for the electric drivetrain, In step S3, specifically, First, a sample of the electric drivetrain is tested according to the operating conditions set in B2; Then, during the test process, use a collection device to collect and record electrical signals, mechanical signals and environmental signals, the collected signals including current, voltage, rotational speed, torque, power supply end output, mechanical power at the dynamometer end and sample temperature; In step S4, specifically, D1, collect test data according to step S3, and count and record the voltage, current, and power data at the power source end and the rotational speed, torque, and mechanical power data at the dynamometer end; D2, evaluate the operating condition efficiency: use the power rate comparison method or the cumulative energy method to calculate the operating condition efficiency η, specifically, The power rate comparison method is as shown in equation (1), which calculates the power supply terminal output P based on the test time flow t. Ｓｕｐｐｌｙ－ｏｕｔ The mechanical power output by the sample electric drivetrain P ｕｕｔ－ｏｕｔ The purpose of the method is to calculate the percentage of [0010] The cumulative energy method calculates the output electrical energy E at the power source based on the test time flow t as shown in equation (2). Ｓｕｐｐｌｙ－ｏｕｔ The mechanical energy E output by the sample electric drivetrain that accounts for the results ｕｕｔ－ｏｕｔ The purpose of the method is to calculate the percentage of [0025] In step S1, the parameters required for the test are as follows: A1, specifications of an electric drivetrain sample including operating voltage, rotational speed / torque, and speed ratio; A2, target vehicle specifications including passenger car specifications and commercial vehicle specifications, and passenger car specifications divided into compact, normal sedan, MPV, and SUV models, A3, including bench equivalent vehicle specifications including drive type, vehicle weight, dynamic load radius, and tire radius; A method for testing and evaluating the efficiency of driving conditions of an electric drivetrain of an equivalent vehicle, characterized in that in setting the driving equivalent resistance curve of B1, maximum vehicle speed, acceleration performance, factors for starting on a slope, etc. are taken into consideration comprehensively, and the form of the equivalent resistance curve is a linear function or a quadratic function.

2. 11. An electronic device comprising: a processor; and a memory communicatively connected to the processor and used to store instructions executable by the processor, the processor being used to execute the method for testing and evaluating driving condition efficiency of an electric drivetrain of an equivalent vehicle as set forth in claim 1.

3. 11. A server comprising at least one processor and a memory communicatively connected to the processor, the memory storing instructions executable by the at least one processor, the instructions being executed by the processor to cause the at least one processor to perform the method of testing and evaluating driving condition efficiency of an equivalent vehicle electric drivetrain as set forth in claim 1.

4. A computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle as claimed in claim 1.

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