Electric vehicle energy recovery evaluation method

Abstract

The invention provides an electric vehicle energy recovery evaluation method. The method comprises the steps of energy recovery function evaluation, energy recovery process evaluation and energy recovery effect evaluation. Wherein the energy recovery function evaluation comprises operation key evaluation, gear evaluation and threshold evaluation; the energy recovery process evaluation comprises smoothness evaluation and NVH (Noise Vibration and Harshness) evaluation in the energy recovery process of each gear; the energy recovery effect evaluation comprises energy recovery efficiency evaluation. By means of the electric vehicle energy recovery evaluation method, the energy recovery efficiency of the vehicle can be accurately calculated, accurate evaluation of the energy recovery efficiency is achieved, evaluation can be carried out based on selection, use and process of the energy recovery function, more scientific and more comprehensive evaluation of energy recovery is achieved, and the energy recovery efficiency is improved. And the evaluation process and the experiment operation are simple, and rapid evaluation of energy recovery can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle performance evaluation, and in particular to an electric vehicle energy recovery evaluation method. Background Art

[0002] Compared with traditional gasoline vehicles, electric vehicles have the ability to recover energy, which can convert part of the energy during deceleration into electrical energy through the electric motor and store it in the drive battery. Energy recovery can extend the vehicle's range and improve energy utilization. It is an important technology for electric vehicles, but there is no mature corresponding subjective evaluation method at this stage. The existing evaluation method mainly focuses on the efficiency of energy recovery, and does not include the selection and use of the energy recovery function and the evaluation of the process. Summary of the invention

[0003] The present invention provides an electric vehicle energy recovery evaluation method to achieve a more comprehensive, scientific and accurate evaluation of electric vehicle energy recovery.

[0004] To achieve the above-mentioned purpose, an embodiment of the present invention provides an electric vehicle energy recovery evaluation method, including energy recovery function evaluation, energy recovery process evaluation, and energy recovery effect evaluation; wherein, the energy recovery function evaluation includes operation key evaluation, gear evaluation, and threshold evaluation; the energy recovery process evaluation includes smoothness evaluation and NVH evaluation during the energy recovery process of each gear; and the energy recovery effect evaluation includes energy recovery efficiency evaluation.

[0005] Optionally, the energy recovery efficiency evaluation includes: evaluating the energy recovery efficiency by calculating it according to the following formula; Where η is the energy recovery efficiency, U is the energy recovery voltage, I is the energy recovery current, M is the vehicle mass, V0 is the initial speed, V1 is the terminal speed, N is the CLTC curve test condition under which N brakings were performed, n is the total number of samples for each braking, and f is the sampling frequency.

[0006] Optionally, the energy recovery effect evaluation also includes SOC value and remaining cruising range evaluation, and the evaluation is performed by recording the SOC value and remaining cruising range during the vehicle energy recovery process.

[0007] Optionally, the operation key evaluation includes: when the energy recovery operation key is a physical button, determining whether the physical button is within the driver's direct visual position, whether it can be directly operated by reaching out, and whether there are components around it that affect the operating space; when the energy recovery operation key is an on-screen button, determining whether there is a quick access method for the on-screen button, whether it can be voice controlled, and whether the button icon is clear.

[0008] Optionally, the gear evaluation includes: judging whether the gear level is reasonable, whether the gear setting can be memorized, whether there are prompt icons or texts for opening and closing each gear, and whether there is an obvious reverse charging energy flow icon when the gear is turned on.

[0009] Optionally, the threshold evaluation includes: judging whether the SOC threshold and speed threshold of energy recovery are reasonable.

[0010] Optionally, the smoothness evaluation includes determining whether there is a ride jerk phenomenon at each energy recovery level of the vehicle, and the NVH evaluation includes determining whether there is abnormal noise or abnormal vibration at each energy recovery level of the vehicle.

[0011] The electric vehicle energy recovery evaluation method of the embodiment of the present invention realizes the evaluation of the energy recovery function by evaluating the energy recovery operation keys, gear positions, thresholds, etc.; realizes the evaluation of the energy recovery process by evaluating the vehicle's driving smoothness and NVH during the energy recovery process; and realizes the evaluation of the energy recovery effect by calculating and evaluating the energy recovery efficiency.

[0012] The electric vehicle energy recovery evaluation method can not only accurately calculate the energy recovery efficiency of the vehicle and realize accurate evaluation of the energy recovery efficiency, but also can evaluate based on the selected use and process of the energy recovery function to realize a more scientific and comprehensive evaluation of energy recovery; moreover, the evaluation process and experimental operation are simple, which can realize a rapid evaluation of energy recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0014] Figure 1 A schematic diagram of an electric vehicle energy recovery evaluation method according to an embodiment of the present invention;

[0015] Figure 2 This is a data schematic diagram of SOC / cruising range evaluation according to an embodiment of the present invention;

[0016] Figure 3 This is a data schematic diagram of a CLTC test according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited to the basic implementation disclosed below.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0019] like Figure 1 As shown, the electric vehicle energy recovery evaluation method of the embodiment of the present invention includes energy recovery function evaluation, energy recovery process evaluation, and energy recovery effect evaluation.

[0020] The energy recovery function evaluation is a human-machine interactive evaluation operation, in which the driver (or evaluation operator) enters the vehicle driving seat and adjusts to a suitable driving posture, observes the position of the energy recovery operation key on the vehicle, and observes the corresponding prompt when energy recovery is turned on. Specifically, the energy recovery function evaluation includes operation key evaluation, gear evaluation, and threshold evaluation; wherein, the operation key evaluation is for the energy recovery operation key, and the operation key includes a switch key and a gear key. If it is a physical key (including an independently set switch key and a gear key, or an integrated switch key and a gear key), check whether the physical key is in the driver's direct visual position, whether it can be directly operated by reaching out, and whether there are any parts around that affect the operating space. If the physical key is in the driver's direct visual range, within the range of reaching out to operate, and there are no other parts around that affect the operation, it can be convenient for the driver to perform energy recovery switch and gear adjustment operations during driving, and the operation key setting can be evaluated as reasonable. If it is an in-screen button, check whether there is a quick access method for the in-screen button, whether it can be voice controlled, and whether the button icon is clear. If there is a quick access method for the in-screen button and the button icon is clear, and it can be voice controlled, it can be convenient for the driver to operate the energy recovery switch and gear adjustment during driving, and the operation key setting can be evaluated as reasonable.

[0021] The gear evaluation is aimed at the energy recovery gear (level or intensity), including checking whether the gear level is reasonable, whether the gear setting can be memorized, whether there are prompt icons or texts for opening and closing each gear, and whether there is an obvious reverse charging energy flow icon when the gear is turned on. Specifically, the driver checks whether the number of gear setting levels is too few or too many. For example, if three energy recovery gears of high, medium and low are set, the gear setting is evaluated as reasonable; if only one energy recovery gear is set or a large number of energy recovery gears are set, and there are problems such as inconvenient adjustment of energy recovery intensity and inconvenient operation, the gear setting is evaluated as unreasonable. During the process of turning on energy recovery and adjusting the gear, if the driver observes the prompt information of turning on energy recovery and the corresponding gear, and there is a reverse charging energy flow icon, which enables the driver to accurately understand the energy recovery status of the vehicle, it can be evaluated as a reasonable gear function setting. When the driver turns on energy recovery and checks whether the energy recovery gear is consistent with the gear before powering off when the vehicle is powered off and then powered on again, it can be determined whether the gear memory function is available.

[0022] The threshold evaluation is for the SOC threshold and speed threshold of energy recovery. Since the energy recovery action is not at the full speed range and full SOC value, energy recovery will not be started when the speed is too low or the SOC value is too high. For example, when the SOC threshold is usually set to 80-95%, the speed threshold is usually set to 10-180km / h. The energy recovery function can only be started when the conditions are met. The driver can judge the SOC threshold and speed threshold of energy recovery by turning on energy recovery at different SOC values ​​and different speeds and observing the stop of energy recovery. If the SOC threshold and speed threshold are within the normal range, the threshold setting can be evaluated as reasonable; if the SOC threshold is too low or the speed threshold is too low and exceeds the normal range, the threshold setting can be evaluated as unreasonable.

[0023] In the embodiment of the present invention, the following methods can be used when performing operation key evaluation, gear position evaluation, and threshold value evaluation: (1) the driver enters the driving seat and checks the energy recovery operation key; (2) respectively turns on each gear position of energy recovery and pays attention to the instrument information display; (3) releases the accelerator during vehicle driving and observes the change in energy flow; (4) the vehicle is powered off and then powered on again, and pays attention to whether the energy recovery level is consistent with that before powering off.

[0024] The energy recovery process evaluation includes the smoothness evaluation and NVH evaluation during the energy recovery process of each gear; optionally, it also includes a brake light evaluation, that is, when the recovery deceleration degree is too high, it determines whether the brake lights are automatically lit. Specifically, the driver can turn on each energy recovery level during the vehicle deceleration process, and feel whether the vehicle has any sense of frustration during the deceleration process of each speed segment of the vehicle, especially near the speed recovery threshold, to evaluate the vehicle's driving smoothness during the energy recovery process; and feel whether the vehicle has any abnormal noise or abnormal vibration, to evaluate the vehicle's NVH during the energy recovery process; and, when the energy recovery level is high, observe whether the brake lights are on. Among them, when the energy recovery level is low (weak), the deceleration is ≤0.7m / s 2 , the brake light is not on; when the energy recovery level is medium, the deceleration is 0.7-1.3m / s 2 , the brake lights can be turned on; when the energy recovery level is high (strong), the deceleration is ≥1.3m / s 2 , the brake lights must be turned on.

[0025] The evaluation of energy recovery effect includes: SOC value and cruising range evaluation, energy recovery efficiency evaluation, among which, SOC value and remaining cruising range evaluation can be achieved by turning on energy recovery while driving the vehicle, recording SOC and remaining cruising range, and judging the impact of energy recovery on the change of battery power or remaining cruising range based on the recorded data, thereby demonstrating the energy recovery effect. For example, two vehicles with equivalent battery capacity are selected (one is an evaluation vehicle, and the other is a competitor vehicle / reference vehicle), and the air-conditioning parameters, energy recovery level settings, and loads of the two vehicles are kept consistent, and both are charged to 100%; the two test vehicles follow the same evaluation route, and the cruising range in different scenarios is evaluated simultaneously (try to keep the vehicle speed consistent), mainly going uphill and downhill; the SOC and remaining cruising range are recorded every 5 km during driving, and the recorded data is statistically analyzed as follows: Figure 2 As shown, the effect of energy recovery is demonstrated by the slope of SOC / actual cruising range during going uphill and downhill.

[0026] Energy recovery efficiency evaluation is evaluated by calculating the energy recovery efficiency. It can be evaluated by running the CLTC curve in a 25℃ room temperature test room, and recording the current I, voltage U, speed V (such as Figure 3 As shown), the energy recovery efficiency of the entire CLTC curve process is calculated based on the data. Specifically, according to the formula:

[0027]

[0028] Calculation is performed, where η is the energy recovery efficiency, U is the energy recovery voltage, I is the energy recovery current, M is the vehicle mass, V0 is the initial speed, V1 is the terminal speed, N is the CLTC curve test condition with N braking times (λ is the λth braking among N braking times, λ≤N), n is the total number of sampling times for each braking (i is the i-th data among n sampling data, i≤n), and f is the sampling frequency.

[0029] The energy recovery efficiency is calculated according to this method, which takes into account factors such as ambient temperature and standard operating conditions. It can give a more accurate calculation of the energy recovery efficiency and achieve a horizontal comparison of the energy recovery effects of different vehicles.

[0030] It should be pointed out that, according to the needs of implementation, the various methods / steps described in the embodiments of the present invention can be split into more methods / steps, or two or more methods / steps or parts of methods / steps can be combined into new methods / steps to achieve the purpose of the embodiments of the present invention.

[0031] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A method for evaluating energy recovery of electric vehicles, It is characterized in that It includes energy recovery function evaluation, energy recovery process evaluation, and energy recovery effect evaluation; among them, The energy recovery function evaluation includes operation key evaluation, gear position evaluation, and threshold evaluation; The energy recovery process evaluation includes a smoothness evaluation and NVH evaluation during the energy recovery process of each gear; The energy recovery effect evaluation includes energy recovery efficiency evaluation.

2. The electric vehicle energy recovery evaluation method according to claim 1, It is characterized in that The energy recovery efficiency evaluation includes: calculating the energy recovery efficiency according to the following formula for evaluation; Where η is the energy recovery efficiency, U is the energy recovery voltage, I is the energy recovery current, m is the vehicle mass, V 0 is the initial velocity, V 1 is the termination speed, N is the N braking times in the CLTC curve test condition, n is the total number of sampling times for each braking, and f is the sampling frequency.

3. The electric vehicle energy recovery evaluation method according to claim 1, It is characterized in that The energy recovery effect evaluation also includes SOC value and remaining cruising range evaluation, which is performed by recording the SOC value and remaining cruising range during the vehicle energy recovery process.

4. The electric vehicle energy recovery evaluation method according to claim 1, It is characterized in that The operation key evaluation includes: when the energy recovery operation key is a physical key, judging whether the physical key is in the driver's direct visual position, whether it can be directly operated by reaching out, and whether there are parts around it that affect the operating space; when the energy recovery operation key is an on-screen key, judging whether there is a quick access method for the on-screen key, whether it can be voice controlled, and whether the button icon is clear.

5. The electric vehicle energy recovery evaluation method according to claim 1, It is characterized in that The gear evaluation includes: judging whether the gear level is reasonable, whether the gear setting can be memorized, whether there are prompt icons or texts for opening and closing each gear, and whether there is an obvious reverse charging energy flow icon when the gear is opened and braked.

6. The electric vehicle energy recovery evaluation method according to claim 1, It is characterized in that The threshold evaluation includes: judging whether the SOC threshold and speed threshold of energy recovery are reasonable.

7. The electric vehicle energy recovery evaluation method according to claim 1, It is characterized in that The smoothness evaluation includes determining whether there is a driving jerk phenomenon at each energy recovery level of the vehicle, and the NVH evaluation includes determining whether there is abnormal noise or abnormal vibration at each energy recovery level of the vehicle.

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