Method for quickly estimating energy consumption of electric vehicle

Abstract

The invention relates to a rapid estimation method for energy consumption of an electric vehicle, and the method comprises the following steps: S1, carrying out random combination according to a driving mode and an energy recovery mode of the vehicle to obtain a plurality of driving preferences, and selecting a plurality of environment temperature values in a preset environment temperature change range, performing multiple groups of driving / braking energy efficiency test experiments on each driving preference of the vehicle under each environment temperature value to obtain test data of each group of driving / braking energy efficiency test experiments; s2, performing data processing on each group of test data to obtain energy conversion efficiency of various driving preferences under various environment temperature values; s3, interpolating the environment temperature value of each driving preference to obtain energy conversion efficiency under each interpolated environment temperature value of each driving preference, and establishing an energy conversion efficiency database; and S4, acquiring the driving state data of the to-be-detected vehicle, and processing the driving state data of the to-be-detected vehicle to estimate the energy consumption of the to-be-detected vehicle. The method can effectively estimate the vehicle energy consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a rapid estimation method of energy consumption of electric vehicles. BACKGROUND

[0002] With the rapid development of the market of pure electric vehicles, consumers pay more and more attention to the performance indicators such as the endurance and energy consumption performance of electric vehicles.

[0003] The current estimation method of energy consumption of pure electric vehicles has the following limitations: 1. The existing technology mainly focuses on the standardized test of single working condition (such as NEDC, WLTC standard working condition), and does not consider the influence of non-standard working condition on battery efficiency and power system efficiency, which may cause deviation between the test results and the display application scene; 2. The test process of the existing technology usually ignores the energy consumption difference of driving modes such as motion / economy / comfort, which may cause deviation between the measured data and the actual vehicle scene of the user; 3. The existing technology mainly tests in a fixed temperature (20-30℃), but the temperature range of the actual user vehicle scene is wider (such as-20℃ low temperature / 40℃ high temperature), and the temperature range of the user vehicle scene covered in the test process is smaller.

[0004] In summary, the estimation method of energy consumption of pure electric vehicles in the prior art is not accurate enough due to the insufficient comprehensive test working condition, the driving mode not considered in the test process, and the smaller temperature range of the user vehicle scene covered in the test process. SUMMARY

[0005] The purpose of the present application is to provide a rapid estimation method of energy consumption of electric vehicles to solve the problem of inaccurate estimation of energy consumption of electric vehicles in the prior art.

[0006] In order to achieve the above purpose, the technical solution adopted by the present application is as follows:

[0007] A rapid estimation method of energy consumption of electric vehicles, comprising the following steps:

[0008] S1: obtaining a plurality of driving preferences by randomly combining the driving modes and energy recovery modes of the vehicle, selecting a plurality of environmental temperature values within a predetermined environmental temperature variation range, and performing a plurality of driving / braking energy efficiency test experiments on each of the driving preferences of the vehicle at each of the environmental temperature values to obtain test data of each of the driving / braking energy efficiency test experiments;

[0009] S2: processing the test data of each group to obtain the energy conversion efficiency of each driving preference at each environmental temperature value;

[0010] S3: interpolating each of the ambient temperature values of each of the driving preferences by an interpolation method to obtain an energy conversion efficiency at each of the interpolated ambient temperature values of each of the driving preferences, and establishing an energy conversion efficiency database according to the energy conversion efficiencies of each group of driving / braking energy efficiency test experiments of the plurality of driving preferences and the energy conversion efficiencies at each of the interpolated ambient temperature values;

[0011] S4: collecting driving state data of a to-be-tested vehicle, matching a corresponding energy conversion efficiency in the energy conversion efficiency database according to the driving state data of the to-be-tested vehicle, and processing the driving state data of the to-be-tested vehicle to estimate the energy consumption of the to-be-tested vehicle.

[0012] According to the above technical means, a plurality of driving preferences are obtained by randomly combining the driving modes and energy recovery modes of the vehicle, each driving preference is tested, the influence of the driving mode and the energy recovery mode of the vehicle on the energy consumption is considered during the testing process, the deviation between the measured data and the actual scene of the user is reduced, the comprehensiveness and reliability of the test results are increased, and the energy consumption of the vehicle can be accurately obtained; a plurality of ambient temperature values are selected within a preset ambient temperature change range, a plurality of groups of driving / braking energy efficiency test experiments are performed on each of the driving preferences of the vehicle at each of the ambient temperature values, the corresponding energy conversion effects of each experiment are obtained, and the energy conversion efficiencies corresponding to the temperature and the driving preference within the preset ambient temperature change range are obtained through the interpolation method, which can cover the temperature range of all actual user vehicle scenes, so that the test results are more comprehensive; the ambient temperature, the driving mode of the vehicle, the energy recovery mode of the vehicle and different working conditions of the vehicle are considered during the calculation of the energy consumption of the vehicle, so that the estimated energy consumption of the vehicle is more accurate and closer to the real scene.

[0013] Further, the test data in S1 includes a wheel end speed of the vehicle, a wheel end torque of the vehicle, an output voltage of a power battery of the vehicle and an output current of the power battery of the vehicle.

[0014] Further, the processing of the test data in S2 specifically includes:

[0015] The energy conversion efficiency of the driving energy efficiency test experiment is calculated as follows:

[0016]

[0017] wherein, η d represents the energy conversion efficiency of the driving energy efficiency test experiment, n d,i represents the wheel end speed of the i th driving working point, T d,i represents the wheel end torque of the i th driving working point, U d,iThe power battery output voltage of the i-th driving working point, I d,i The power battery output current of the i-th driving working point.

[0018] According to the above technical means, the energy conversion efficiency of the driving energy efficiency test experiment can be accurately calculated.

[0019] Further, the processing of the test data in S2 further includes:

[0020] The energy conversion efficiency of the braking energy efficiency test experiment is calculated as follows:

[0021]

[0022] η r The energy conversion efficiency of the braking energy efficiency test experiment, n r,i The wheel end speed of the i-th braking working point, T r,i The wheel end torque of the i-th braking working point, U r,i The power battery output voltage of the i-th braking working point, I r,i The power battery output current of the i-th braking working point.

[0023] According to the above technical means, the energy conversion efficiency of the braking energy efficiency test experiment can be accurately calculated.

[0024] Further, it further includes S0:

[0025] S0: The test vehicle is subjected to a coasting test to obtain the coasting resistance curve of the test vehicle, and then obtain the road load constant, the road load first term coefficient and the road load second term coefficient of the test vehicle.

[0026] Further, the driving state data of the test vehicle in S4 includes driving preference, speed of the test vehicle, rolling radius of the test vehicle, environmental temperature and pedal opening degree of driving / braking of the test vehicle.

[0027] Further, the processing of the driving state data of the test vehicle in S4 specifically includes:

[0028] S41: According to the environmental temperature, the driving preference, the speed of the test vehicle and the pedal opening degree of driving / braking of the test vehicle, match the energy conversion efficiency in the energy conversion efficiency database;

[0029] S42: obtaining the energy consumption of the vehicle to be tested according to the corresponding energy conversion efficiency, the road load constant of the vehicle to be tested, the first-order coefficient of the road load of the vehicle to be tested and the second-order coefficient of the road load of the vehicle to be tested, the speed of the vehicle to be tested, and the rolling radius of the vehicle to be tested.

[0030] Further, the energy consumption calculation formula of the vehicle to be tested in S42 is as follows:

[0031]

[0032] wherein EC represents the energy consumption of the vehicle to be tested for a preset distance, a represents the road load constant of the vehicle to be tested, b represents the first-order coefficient of the road load of the vehicle to be tested, c represents the second-order coefficient of the road load of the vehicle to be tested, v represents the speed of the vehicle to be tested, r represents the rolling radius of the vehicle, η represents the corresponding energy conversion efficiency, and S represents the preset distance of the vehicle to be tested.

[0033] Further, each of the brake / drive energy efficiency experiments in S1 comprises the following steps:

[0034] S11: obtaining the ambient temperature, adjusting the average temperature of the interior head of the vehicle to a preset value according to the ambient temperature value, setting the initial target speed of the vehicle and the target opening degree of the initial brake / drive pedal of the vehicle;

[0035] S12: adjusting the speed of the vehicle to the target speed and adjusting the brake / drive pedal of the vehicle to the target opening degree, keeping the vehicle running state for a first preset time period to continuously collect the test data of the vehicle;

[0036] S13: adjusting the target speed and the target opening degree of the brake / drive pedal, repeating S12 until the test data collection of the vehicle in the brake / drive energy efficiency experiment under the ambient temperature is completed.

[0037] According to the above technical means, the test data of the vehicle under each driving preference condition, each ambient temperature and each drive / brake energy efficiency experiment can be obtained.

[0038] Further, the preset ambient temperature varies in the range of [-20℃, 40℃].

[0039] According to the above technical means, the preset ambient temperature varies in the range of [-20℃, 40℃], which can cover the actual driving scene temperature range of the user.

[0040] The beneficial effects of the present application are as follows:

[0041] 1. A plurality of driving preferences are obtained by randomly combining the driving mode and the energy recovery mode of the vehicle, and the driving preferences are tested, and the effects of the driving mode and the energy recovery mode of the vehicle on energy consumption are considered during the testing process, thereby reducing the deviation between the measured data and the actual user scenario, increasing the comprehensiveness and reliability of the test results, and accurately obtaining the energy consumption of the vehicle.

[0042] 2. A plurality of ambient temperature values are selected within a preset ambient temperature variation range, and a plurality of driving / braking energy efficiency test experiments are performed on each of the driving preferences of the vehicle at each of the ambient temperature values, to obtain the energy conversion effect corresponding to each experiment, and the energy conversion efficiency corresponding to the temperature and the driving preference within the preset ambient temperature variation range is obtained through interpolation, thereby covering the temperature range of all actual user vehicle scenarios, and making the test results more comprehensive.

[0043] 3. The environmental temperature, the driving mode of the vehicle, the energy recovery mode of the vehicle, and different working conditions of the vehicle are considered during the calculation of the energy consumption of the vehicle, thereby making the estimated energy consumption of the vehicle more accurate and closer to the real scenario. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 a flowchart of step S4 in embodiment one;

[0045] Figure 2 a flowchart of step S1 in embodiment one;

[0046] Figure 3 a flowchart of step S1 in embodiment one;

[0047] Figure 4 a model diagram of embodiment two. DETAILED DESCRIPTION

[0048] The embodiments of the present application will be described below with reference to the accompanying drawings and preferred embodiments, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure in the specification. The present application can also be implemented or applied by different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustration of the present application, and are not intended to limit the protection scope of the present application.

[0049] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concepts of the present application, and only the components related to the present application are shown in the diagrams, rather than being drawn according to the number, shape and size of the components in actual implementation. The actual implementation of each component may be a random change, and the component layout pattern may be more complex.

[0050] Embodiment one

[0051] Before the experiment starts, a coasting test can be performed in advance on the vehicle to be tested to obtain the road load constant of the vehicle to be tested, the road load first-order coefficient of the vehicle to be tested, and the road load second-order coefficient of the vehicle to be tested.

[0052] S1: In this embodiment, the driving mode includes an economy mode, a standard mode and a sport mode, the energy recovery mode includes a strong recovery mode and a weak recovery mode, and the driving preference includes six driving preferences obtained by randomly combining the driving mode with the energy recovery mode.

[0053] The three driving modes and the two energy recovery modes are randomly combined to obtain six driving preferences, which are an economy driving mode and a strong energy recovery mode, a standard driving mode and a strong energy recovery mode, a sport driving mode and a strong energy recovery mode, an economy driving mode and a weak energy recovery mode, a standard driving mode and a weak energy recovery mode, and a sport driving mode and a weak energy recovery mode.

[0054] Five environmental temperature points of -20℃, -7℃, 23℃, 30℃ and 40℃ are selected in the preset environmental temperature variation range of [-20℃, 40℃], wherein -20℃ and -7℃ are referred to as low temperature, 23℃ is referred to as normal temperature, and 30℃ and 40℃ are referred to as high temperature, i.e., three environmental temperatures are divided.

[0055] In the three environments, a plurality of driving / braking energy efficiency test experiments are performed under each driving preference at each environmental temperature value (as shown in Table 1), to obtain test data of each driving / braking energy efficiency test experiment.

[0056] Table 1

[0057]

[0058] The steps of the driving / braking energy efficiency test experiment specifically include:

[0059] S11: Obtain an environmental temperature, and first adjust the average temperature of the interior head of the vehicle to a preset value according to the environmental temperature value; set an initial target vehicle speed of the vehicle and a target opening degree of an initial brake / drive pedal of the vehicle;

[0060] S12: adjust the speed of the vehicle to the target speed, and adjust the brake / drive pedal of the vehicle to the target opening, keep the vehicle running state for a first preset time period to continuously collect the test data of the vehicle;

[0061] S13: adjust the target speed and the target opening of the brake / drive pedal, repeat S12 until the test data collection of the vehicle in the brake / drive energy efficiency test under the ambient temperature is completed.

[0062] In the embodiment, the first preset time period is 10 seconds.

[0063] In the embodiment, the preset value of the average temperature of the internal head of the vehicle is set according to the ambient temperature, preferably, when the ambient temperature value is greater than or equal to 30℃, the preset value is (24±1)℃; when the ambient temperature value is less than or equal to -7℃, the preset value is (21±1)℃, when the ambient temperature is less than 30℃ and greater than -7℃, the average temperature of the internal head of the vehicle is not adjusted, that is, the preset value is the ambient temperature, and the test data includes the wheel end speed of the vehicle, the wheel end torque of the vehicle, the output voltage of the power battery of the vehicle and the output current of the power battery of the vehicle.

[0064] S2: data processing is performed on each group of test data to obtain the energy conversion efficiency of each driving preference under each ambient temperature value, which can be adjusted according to specific test items.

[0065] Specifically, when the energy efficiency test experiment of the vehicle power system in the driving state (i.e. the power battery in the discharging state), the energy conversion efficiency is calculated as follows:

[0066]

[0067] ηd=∑ni=1ηd,i d ηd represents the energy conversion efficiency of the driving energy efficiency test experiment, n d,i ni represents the wheel end speed of the i th driving working point, T d,i ni represents the wheel end torque of the i th driving working point, U d,i ni represents the output voltage of the power battery of the i th driving working point, I d,i ni represents the output current of the power battery of the i th driving working point.

[0068] Specifically, when the energy efficiency test experiment of the vehicle power system in the recovery state (i.e. the power battery in the charging state), the energy conversion efficiency is calculated as follows:

[0069]

[0070] ηb=∑ni=1ηb,i r ηb represents the energy conversion efficiency of the brake energy efficiency test experiment, nr,i wheel end rotational speed of the i-th braking working point, T r,i wheel end torque of the i-th braking working point, U r,i power battery output voltage of the i-th braking working point, I r,i power battery output current of the i-th braking working point.

[0071] In this embodiment, the i-th driving working point is specifically the i-th set of driving energy efficiency test experiments, that is, the wheel end rotational speed of the i-th driving working point is the wheel end rotational speed of the vehicle in the i-th set of driving energy efficiency test experiments. Similarly, the i-th braking working point is specifically the i-th set of braking energy efficiency test experiments.

[0072] S3: For each driving preference, based on the energy conversion efficiency of the five environmental temperature values (i.e. -20℃, -7℃, 23℃, 30℃ and 40℃), an energy conversion efficiency matrix of continuous environmental temperature values with an interval of 1℃ is generated in the temperature interval of [-20, 40]℃ for each driving preference by interpolation method (i.e. according to the five environmental temperature values and the corresponding energy conversion efficiency, the corresponding relationship between them is obtained, and the environmental temperature values in the temperature interval of [-20, 40]℃ are selected and the corresponding energy conversion efficiency is obtained according to the corresponding relationship), and an energy conversion efficiency database is established according to the energy conversion efficiency matrix under various driving preferences;

[0073] S4: Collecting the driving state data of the vehicle to be tested, which includes driving preference, speed of the vehicle to be tested, rolling radius of the vehicle to be tested, environmental temperature and pedal opening degree of braking / driving of the vehicle to be tested, and then performing the following steps:

[0074] S41: According to the environmental temperature, the driving preference, the speed of the vehicle to be tested and the pedal opening degree of driving / braking of the vehicle to be tested, the energy conversion efficiency in the energy conversion efficiency database is matched;

[0075] S42: According to the corresponding energy conversion efficiency, the road load constant of the vehicle to be tested, the first order coefficient of road load of the vehicle to be tested and the second order coefficient of road load of the vehicle to be tested, the speed of the vehicle to be tested, the rolling radius of the vehicle to be tested, the energy consumption of the vehicle to be tested is obtained.

[0076] In this embodiment, when based on single-point instantaneous vehicle speed, the energy consumption calculation formula of the vehicle to be tested in S42 is as follows:

[0077]

[0078] Where EC represents the energy consumption of the vehicle under test over a preset distance, a represents the road load constant of the vehicle under test, b represents the first-order coefficient of the road load of the vehicle under test, c represents the second-order coefficient of the road load of the vehicle under test, v represents the speed of the vehicle under test, r represents the rolling radius of the vehicle, η represents the corresponding energy conversion efficiency, and S represents the preset distance of the vehicle under test.

[0079] In this preferred embodiment, S is set to 100, meaning EC represents the energy consumption per 100 kilometers of the vehicle under test.

[0080] When the driving status data of the vehicle under test is a segment of user driving condition data, the energy consumption of the vehicle under test in S42 specifically includes: first, acquiring the wheel-end power at each moment, and matching the driving status data at each moment with the energy conversion efficiency in the energy conversion efficiency database to obtain the energy conversion efficiency at each moment; then, acquiring the power battery output power of the vehicle under test at each moment, summing the power output of the power battery in the entire driving condition, and calculating the driving mileage by integrating the vehicle speed in the entire driving condition; finally, obtaining the ratio of the sum of the power battery output power to the driving mileage as the energy consumption per kilometer of the vehicle under test, and multiplying it by the preset mileage as the energy consumption of the vehicle under test within the preset mileage.

[0081] Example 2

[0082] like Figure 4 As shown, this embodiment proposes a vehicle energy consumption analysis and calculation model (hereinafter referred to as the model). The construction of the model includes steps S0 to S4 in Embodiment 1.

[0083] The model usage process is as follows: The driving preferences of the vehicle under test, the speed of the vehicle under test, the ambient temperature, the accelerator / brake pedal opening of the vehicle under test, and the preset mileage are input into the model. This allows for the estimation of the energy consumption of the vehicle over a preset distance. The specific process is as follows:

[0084] The energy conversion efficiency in the energy conversion efficiency database is obtained by matching driving preferences, the speed of the vehicle under test, ambient temperature, and the opening of the drive / brake pedals of the vehicle under test.

[0085] The road load constant, the first term coefficient and the second term coefficient of the road load of the test vehicle are obtained from the coasting test results, and the coasting resistance is obtained from the coasting resistance and the wheel end torque. The wheel end power is then obtained by processing the wheel end power and the energy conversion efficiency obtained by matching.

[0086] The speed of the vehicle under test is then integrated to obtain the vehicle's mileage.

[0087] The driving mileage, the preset mileage and the power battery power are processed to obtain the energy consumption of the to-be-tested vehicle within the preset mileage.

[0088] The above embodiments are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent substitutions or transformations made by those skilled in the art based on the present application are within the protection scope of the present application.

Claims

1. A method for fast estimation of energy consumption of an electric vehicle, characterized in that, The method comprises the following steps: S1: obtaining multiple driving preferences according to random combination of driving modes and energy recovery modes of a vehicle, selecting multiple ambient temperature values within a preset ambient temperature variation range, and performing multiple sets of driving / braking energy efficiency test experiments on each driving preference of the vehicle at each ambient temperature value to obtain test data of each set of driving / braking energy efficiency test experiments; S2: processing each set of test data to obtain energy conversion efficiency of each driving preference at each ambient temperature value; S3: interpolating each ambient temperature value of each driving preference at every interval of 1℃ by an interpolation method to obtain energy conversion efficiency at each interpolated ambient temperature value of each driving preference, and establishing an energy conversion efficiency database according to energy conversion efficiency of each set of driving / braking energy efficiency test experiments of multiple driving preferences and energy conversion efficiency at each interpolated ambient temperature value; S4: collecting driving state data of a vehicle to be tested, matching corresponding energy conversion efficiency in the energy conversion efficiency database according to the driving state data of the vehicle to be tested, and processing the driving state data of the vehicle to be tested to estimate energy consumption of the vehicle to be tested.

2. The method of claim 1, wherein, The test data in S1 comprises wheel end rotating speed of the vehicle, wheel end torque of the vehicle, output voltage of a power battery of the vehicle, and output current of the power battery of the vehicle.

3. The method of claim 2, wherein, Processing the test data in S2 specifically comprises: The energy conversion efficiency of the driving energy efficiency test experiment is calculated as follows: η d represents the energy conversion efficiency of the driving energy efficiency test experiment, n d,i represents the wheel end rotational speed of the i-th driving operating point, T d,i represents the wheel end torque of the i-th driving operating point, U d,i represents the power battery output voltage of the i-th driving operating point, I d,i represents the power battery output current of the i-th driving operating point.

4. The method of claim 2, wherein, Processing the test data in S2 comprises: The energy conversion efficiency of the braking energy efficiency test experiment is calculated as follows: wherein η r represents the energy conversion efficiency of the brake energy efficiency test experiment, n r,i represents the wheel end rotational speed of the i-th brake operating point, T r,i represents the wheel end torque of the i-th brake operating point, U r,i represents the power battery output voltage of the i-th brake operating point, I r,i represents the power battery output current of the i-th brake operating point.

5. The method of claim 1, wherein, Further comprising S0: S0: performing a coasting test on the vehicle to be tested to obtain a coasting resistance curve of the vehicle to be tested, and further obtain a road load constant, a road load first term coefficient, and a road load second term coefficient of the vehicle to be tested.

6. The method of claim 5, wherein, The driving state data of the vehicle to be tested in S4 comprises driving preference, speed of the vehicle to be tested, rolling radius of the vehicle to be tested, ambient temperature, and pedal opening degree of braking / driving of the vehicle to be tested.

7. The method of claim 6, wherein, Processing the driving state data of the vehicle to be tested in S4 specifically comprises: S41: matching energy conversion efficiency in the energy conversion efficiency database according to the ambient temperature, the driving preference, the speed of the vehicle to be tested, and the pedal opening degree of driving / braking of the vehicle to be tested; S42: obtaining energy consumption of the vehicle to be tested according to the corresponding energy conversion efficiency, the road load constant of the vehicle to be tested, the road load first term coefficient of the vehicle to be tested, the road load second term coefficient of the vehicle to be tested, the speed of the vehicle to be tested, and the rolling radius of the vehicle to be tested.

8. The method of claim 7, wherein, The energy consumption calculation formula of the vehicle to be tested in S42 is as follows: Wherein, EC represents the energy consumption of the preset route of the vehicle to be tested, a represents the road load constant of the vehicle to be tested, b represents the road load first-order coefficient of the vehicle to be tested, c represents the road load second-order coefficient of the vehicle to be tested, v represents the speed of the vehicle to be tested, r represents the rolling radius of the vehicle, η represents the corresponding energy conversion efficiency, and S represents the preset route of the vehicle to be tested.

9. The method of claim 1, wherein, The brake / drive energy efficiency experiment in S1 includes the following steps: S11: Obtain the ambient temperature, and adjust the average temperature of the head of the interior of the vehicle to a preset value according to the ambient temperature value; Set the initial target speed of the vehicle and the target opening of the initial brake / drive pedal of the vehicle; S12: Adjust the speed of the vehicle to the target speed and the brake / drive pedal of the vehicle to the target opening, keep the vehicle running state for a first preset time period, and continuously collect the test data of the vehicle; S13: Adjust the target speed and the target opening of the brake / drive pedal, repeat S12, and until the test data collection of the vehicle in the brake / drive energy efficiency experiment under the ambient temperature is completed.

10. The method of claim 1, wherein, The preset ambient temperature changes in the range of [-20℃, 40℃].

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