Method for testing and evaluating driving condition efficiency of electric drivetrain 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 more particularly 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 electrical energy supplied by the battery into mechanical energy to drive the vehicle. The efficiency of the energy conversion process directly affects the vehicle's power performance and driving range. Therefore, high rotational speed / torque ratio and high energy efficiency for high-voltage vehicle platforms have become the development trend of electric drivetrain products.

[0003] In bench efficiency testing of electric drivetrains, it is common to present the efficiency in the form of a map at this stage, with reference to GB / T18488.2 "Electric Vehicle Drive Motor Systems Part 2: Test Methods" and T / CSAE143-2020 "Evaluation Specifications for Integrated Electric Drivetrains of Pure Electric Passenger Vehicles." Efficiency map test results for electric drivetrains not only reflect the system's efficiency distribution at various rotational speed and torque setting operating conditions, but also reflect the system's output characteristics, making them widely used in system research and development testing.

[0004] However, bench efficiency testing methods for electric drivetrains have certain limitations. On the one hand, while a vehicle is operating, driving conditions must be frequently changed to adapt to various road conditions. Existing bench tests are limited to a few steady-state equivalent driving conditions and cannot fully test the driving conditions of equivalent vehicle operation. On the other hand, transient time-varying factors such as temperature rise and harmonic losses during actual system operation are not taken into account, which is significantly different from the system's actual application scenario. In addition, bench efficiency results for electric drivetrains are limited to efficiency at a certain steady-state constant speed point, efficiency section, percentage of high-efficiency zone, and highest efficiency point, which have relatively little relevance to the vehicle's test driving conditions.

[0005] In summary, existing electric drivetrain efficiency tests for real-world driving scenarios lack correlation with the actual driving conditions of a vehicle, and there is an urgent need for a method to test and evaluate the driving condition efficiency of an equivalent vehicle's electric drivetrain in order to improve the performance of electric drivetrain products and increase the vehicle's range performance. 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 the 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 necessary specifications 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 from step S3.

[0008] Furthermore, in step S1, the specifications required for the test are as follows: A1, specifications of the electric drivetrain sample 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 the equivalent resistance curve of the target vehicle model: According to the determined target vehicle model, the specifications of the target vehicle model are obtained and the equivalent running resistance curve is set. B2, Determining the test driving conditions: Including selecting the test driving conditions, setting the time flow rotation speed / torque curve, and inputting the driver model. B3, Tuning and Loading Upper Computer Parameters: The sample control logic for the electric drivetrain is torque control, which is used to control acceleration and braking power.

[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 is in the form of a linear function or a quadratic function.

[0011] Furthermore, when 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. The time-flow rotational speed / torque curve configuration includes sample motorized and powered states for the electric drivetrain.

[0012] Furthermore, step S3 is specifically as follows. First, a sample of the electric drivetrain will be tested according to the operating conditions set in B2. Next, during the testing process, a collection device is used to collect and record electrical, mechanical, and environmental signals, and the collected signals include 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, count and record the voltage, current, and power data at the power supply 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 cumulative energy method to calculate the operating condition efficiency η, specifically: The power consumption comparison method is as shown in equation (1), where the power output P Supply-out The mechanical power P output by the electric drivetrain sample accounts for the results uut-out The goal 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 electric drivetrain sample accounts for the results uut-out The goal 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 to store instructions executable by the processor, said processor being used to perform 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 the driving condition efficiency of an electric drivetrain of an equivalent vehicle as set forth in any one of claims 1 to 7.

[0019] Furthermore, the present solution discloses a computer readable storage medium on which a computer program is stored, which, when executed by a processor, realizes a method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle. [Effects 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) From the perspective of electric drivetrain design, the method for testing and evaluating the efficiency under driving conditions of an equivalent vehicle electric drivetrain according to the present invention 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 electric drivetrain's performance parameters, control strategies, prototype calibration, etc. (2) From the perspective of vehicle development and design, the method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle according to the present invention can realize the calibration and optimization of the performance of an 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 an electric drivetrain of an equivalent vehicle according to the present invention expands the bench efficiency test project from the perspective of testing and evaluating electric drivetrains. The obtained driving condition test results can realize vehicle energy efficiency evaluation of various electric drivetrains, which is beneficial for the classification and evaluation of electric drivetrain products. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a flowchart of a method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle. [Figure 2] FIG. 1 is a structural block diagram of an operating condition efficiency system. [Figure 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. [Figure 5] 1 is a speed / torque time flow curve 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 INVENTION

[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 be described in detail below with reference to the drawings and examples.

[0024] The present invention provides a method for testing and evaluating the driving condition efficiency of an electric drivetrain of an equivalent vehicle (abbreviated as "method"; see Figures 1-7). Through equivalent test driving conditions, the correlation between the electric drivetrain efficiency and the vehicle driving conditions is established, thereby enabling the testing and evaluation of the driving condition efficiency of the electric drivetrain. Figures 1 and 2 show a principle flowchart of the method described in the invention and a structural block diagram of the test system. 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 scope of protection of the present application. This embodiment specifically includes the following steps:

[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 equivalent vehicle specifications and target vehicle specifications for the above step 1.3 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, the equivalent vehicle running resistance curve of the target vehicle is collected based on actual vehicle testing, and the electric drivetrain bench test is targeted. The equivalent vehicle running resistance curve format is selected taking into account the bench input parameters and test operating conditions. In this example, a quadratic function curve format is selected, and the equivalent resistance curve of the target vehicle in the actual vehicle test is as shown in Figure 3. The fitting formula for 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 step 2.2 above, two test driving conditions, NEDC and CLTC, are selected in this example, and start / stop, acceleration / deceleration, and rotational speed / torque switching are controlled by a driver model self-configured on the bench itself. The equivalent vehicle running resistance curves set based on step 2.1 and the rotational speed / torque time flow curves for the two test driving conditions are shown in Figures 4 and 5.

[0036] In step 2.3 above, the test system structure under bench operation conditions is as shown in Figure 2, where the sample control logic of the electric drivetrain is torque control, and the test host computer collects the rotation speed / torque signals of the output end of the sample during the test process and performs negative feedback adjustment on the rotation speed.

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

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

[0039] In step 3.2, high-precision data acquisition equipment is used to collect and record electrical, mechanical, and environmental signals. The recording scale is a time scale, ensuring that test data is collected and stored within the same time frame. The electrical signals are collected using devices such as a power analyzer and oscilloscope. The electrical signals include the power, voltage, and current output from the power supply. The mechanical signals include the rotational speed and torque signals output by the electric drivetrain sample and the mechanical power output from the dynamometer. The rotational speed and torque signals are collected by a rotational speed / torque sensor installed on the bench. The environmental signals include the temperature and humidity of the test environment and the temperature of the electric drivetrain sample during the test process.

[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, and 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 of the operating condition efficiency of the test data. In this example, 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 electric drivetrain sample accounts for the results uut-out This can be interpreted as the proportion of

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

[0044] [Table 3]

[0045] [Table 4]

[0046] [Table 5]

[0047] Those skilled in the art will 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 that in the above description, the configurations and steps of each example have been generally described according to their functions in order to clearly illustrate the compatibility of 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 may implement the described functions using different methods for each specific application, but such implementations should not be considered to go beyond the scope of the present invention.

[0048] In some embodiments provided by the present application, the disclosed methods and systems may be implemented in other ways. For example, the division of the above units is merely a kind of logical functional division. In actual implementation, other division methods are possible. For example, multiple units or components may be combined or integrated into another system, or some functions may be omitted or not performed. The above units may or may not be physically separated, and components 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 may 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 are not intended to 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 it is possible to modify the technical solutions recorded in the above embodiments or to replace some or all of the technical features with equivalents, and these modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate 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 descriptions 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. A method for testing and evaluating the driving condition efficiency of an equivalent vehicle electric drivetrain used in a pure electric passenger 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 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. Determine the test driving conditions: including selecting the test driving conditions, setting the time flow rotation speed / torque curve, and inputting the driver model; B3. Tuning and loading of upper computer parameters: The sample control logic of the electric drivetrain is torque control, which is used to control acceleration and braking power; 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 motored 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 the power supply end output PSuply-out, the mechanical power Puut-out, the power supply end output electrical energy ESupply-out, and the mechanical energy Euut-out; In step S4, specifically, D1, collect test data according to step S3, count and record the voltage, current, and power data at the power supply 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 cumulative energy method to calculate the operating condition efficiency η, specifically: The power comparison method is to calculate the proportion of the mechanical power Puut-out output by the sample electric drivetrain to the power supply end output PSuply-out result based on the test time flow t, as shown in equation (1): [Equation 1] The cumulative energy method is to calculate the proportion of the mechanical energy Euut-out output by the sample electric drivetrain to the power supply terminal output electrical energy ESupply-out result based on the test time flow t, as shown in equation (2): [Equation 2] In step S1, the specifications required for the test are as follows: A1, specifications of an electric drivetrain sample including operating voltage, rotational speed / torque, and speed ratio; A2, the target vehicle specifications including passenger car specifications and commercial vehicle specifications, and the specifications of passenger cars divided into compact, regular sedan, MPV, and SUV models, A3, including bench equivalent vehicle specifications including drive type, vehicle weight, dynamic load radius, and tire radius; In setting the traveling equivalent 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 is in the form of a linear function or a quadratic function. Testing and evaluation method for the operating condition efficiency of electric drivetrains.

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

3. 10. A server comprising: at least one processor; and a memory communicatively coupled 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 for testing and evaluating driving condition efficiency of an equivalent vehicle electric drivetrain for use in a pure electric passenger vehicle as set forth in claim 1.

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

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