Self-learning available power acquisition method for electric vehicle instrument display

Abstract

This invention discloses a self-learning available power acquisition method for electric vehicle instrument displays. The main design concept of the invention is to propose a self-learning available power calculation strategy, which includes querying a preset power parameter table through a table lookup operation to obtain the current maximum available power and attenuation factor. The target available power for instrument display is then corrected based on the attenuation factor and combined with the available power, a set correction period, and historical uncorrected power data. The invention can autonomously adjust the available power value for display, unaffected by power attenuation over the battery pack's service life, and is suitable for calculating available power throughout the life cycle of an electric vehicle.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular to a self-learning available power acquisition method for an electric vehicle instrument display. Background Art

[0002] As the name suggests, available power is not actual power, but reflects the available real-time power. The power of electric vehicles comes from batteries, but due to various factors such as temperature, total battery pack voltage, minimum single cell voltage, vehicle failure, etc., the power of the vehicle needs to be limited to prevent the vehicle voltage from being too low and causing irreversible damage to the battery pack.

[0003] With the popularization of new energy vehicle technology, the regulatory requirements for new energy vehicles are becoming more and more detailed. For electric vehicle instrument clusters (ICMs), the industry currently requires that they should be able to display the available power of the entire vehicle. Therefore, a reliable solution for obtaining available power is urgently needed. Summary of the Invention

[0004] In view of the above, the present invention aims to provide a self-learning available power acquisition method for electric vehicle instrument display, so as to meet the industry's demand for display of available power.

[0005] The technical solution adopted in the present invention is as follows:

[0006] The present invention provides a self-learning method for obtaining available power for an electric vehicle instrument display, which includes:

[0007] Query the preset power parameter table through table lookup operation to obtain the maximum available power and attenuation factor at the current moment;

[0008] Correction is performed based on the attenuation factor in combination with the available power, a set correction period, and historical uncorrected power data to obtain a target available power for instrument display.

[0009] In at least one possible implementation, the correction period is set based on a first number of times the vehicle is at full power.

[0010] In at least one possible implementation, the historical uncorrected power data includes: a second number of times that a pre-stored difference between actual power and available power at full power when uncorrected is greater than a preset power difference threshold.

[0011] In at least one possible implementation, the correction is performed based on the attenuation factor in combination with the available power, the set correction period, and historical uncorrected power data to obtain a target available power for meter display, which is calculated according to the following formula:

[0012]

[0013] Among them, P 可用 is the maximum available power at the current moment obtained by looking up the table, δ is the attenuation factor, is the first number, and M is the second number.

[0014] In at least one possible implementation manner, the method further includes: after reaching the correction period, determining a correction trigger condition based on the second number of times, or based on the first number of times and the second number of times.

[0015] In at least one possible implementation, determining the modification trigger condition includes:

[0016] When the second number exceeds a preset upper limit of the second number, it is determined that the correction trigger condition has been met; or,

[0017] When the ratio of the second number of times to the first number of times is greater than a preset ratio value, it is determined that the correction trigger condition has been met.

[0018] In at least one possible implementation, the method further includes: when a correction recovery condition is reached, the displayed available power jumps back to the target available power after the previous correction, wherein the correction recovery condition is that the ratio of the second number to the first number is less than or equal to the preset ratio value.

[0019] The key design concept of this invention lies in a self-learning available power calculation strategy. This strategy involves querying a preset power parameter table through a table lookup to determine the current maximum available power and its attenuation factor. The strategy then applies a correction based on the attenuation factor, combined with the available power, a set correction period, and historical uncorrected power data, to determine the target available power displayed on the meter. This system autonomously adjusts the displayed available power value, unaffected by the power attenuation over the battery pack's lifespan, making it suitable for calculating available power over the lifespan of an electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0021] Figure 1 This is a flow chart of a self-learning available power acquisition method for an electric vehicle instrument display provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0023] The present invention provides an embodiment of a self-learning available power acquisition method for an electric vehicle instrument display.

[0024] Understandably, the battery pack power of electric vehicles is divided into available power and actual power. Available power is further divided into available driving power and available regenerative power, and actual power is further divided into actual driving power and actual regenerative power. The power displayed on the instrument panel is mainly actual driving power and available driving power, but other power values ​​may also need to be displayed.

[0025] Regarding the actual power, it can be calculated based on the motor torque value T of the vehicle bus. 电机 and motor speed value N 电机 The calculation formula is as follows:

[0026]

[0027] This is not the focus of the present invention. The present invention mainly provides the following implementation reference for obtaining available power: Figure 1 As shown:

[0028] Step S1: querying a preset power parameter table through a table lookup operation to obtain the maximum available power and attenuation factor at the current moment;

[0029] Step S2: performing correction according to the attenuation factor in combination with the available power, a set correction period, and historical uncorrected power data to obtain a target available power for instrument display.

[0030] Specifically, the calculation is based on the attenuation parameters of the battery pack (the theoretical values ​​in the power parameter table provided when the battery pack leaves the factory), and different temperatures and different SOCs correspond to the maximum available driving power and maximum available recovery power of the battery pack. Specifically, the VCU can query the preset power parameter table through a table lookup operation to obtain the maximum available power P at the current moment. 可用 However, as the battery pack is used for a longer time, the table value will become inaccurate. To address this problem, the present invention proposes to use the attenuation factor δ provided by the battery pack manufacturer (δ<1 obtained through a large number of experiments in advance) and the available power P obtained by combining it with the power parameter table. 可用 , the set correction period and the historical uncorrected power data are corrected to obtain the target available power for instrument display under non-limited power conditions (Corrected value). It should be pointed out that Not only is the available driving power displayed, but also the available recuperation power is displayed.

[0031] Specifically, the correction cycle here can be the first number of times the vehicle is at full power Set when the preset first limit is reached, e.g. This is a correction cycle.

[0032] In actual operation, the historical uncorrected power data here can be obtained by reading the storage records in the VCU to obtain the second number M of times that the difference between the actual power and the available power under full power conditions without correction is greater than the preset power difference threshold (such as 1kW, which is a calibration value).

[0033] Therefore, the above-mentioned attenuation factor combined with the available power P 可用 , the set correction period and the historical uncorrected power data are corrected to obtain the target available power under non-power-limited conditions. The following formula can be used:

[0034]

[0035] P 可用 is the maximum available power at the current moment obtained by looking up the table, δ is the attenuation factor, is the first number, M is the second number, M can be understood as a correction basis. In this embodiment, the correction basis is the ratio of the difference between the first number and the second number to the first number. Of course, other correction bases can also be used in other embodiments.

[0036] Based on this concept, when the correction period is reached, the correction trigger condition may be determined based on the second number of times, or based on the first number of times and the second number of times. Here are two implementation examples:

[0037] 1) When the second number exceeds a preset upper limit of the second number, the VCU can independently determine that the correction trigger condition has been met.

[0038] 2) Alternatively, when the ratio of the second number of times to the first number of times is greater than a preset ratio value (such as 0.05), it is determined that the correction trigger condition has been met.

[0039] Furthermore, the method also includes jumping the displayed available power back to the target available power after the previous correction when the correction recovery condition is reached, and the correction recovery condition is that the ratio of the second number to the first number is less than or equal to the preset ratio value.

[0040] It can be seen that the present invention can adjust the available power through the autonomous learning judgment of the VCU, and will not cause inaccurate available power due to the increase in the service life of the battery pack.

[0041] In addition, available power for instrument display can also be obtained under power-limited conditions. Here, the present invention divides power limiting types into four types: temperature power limiting, fault power limiting, total voltage power limiting, and single-unit power limiting. For different driving or recovery working conditions, the various power limiting values ​​are summarized under the four power-limited conditions, and the minimum value is taken as the available power value.

[0042] ① Temperature power limit: (applicable to driving or recycling, and in recycling conditions, it can also be divided into high temperature power limit and low temperature power limit)

[0043] When the highest cell temperature reaches the battery pack set temperature range [T1, T2] threshold, the available power is:

[0044]

[0045] ②Fault limiting power: (applicable to drive or recovery)

[0046] When a drive or regeneration power limit fault occurs, the available power is:

[0047] P 故障限功率 =P 蠕行

[0048] Among them, P 蠕行 It is the maximum creeping power of the motor or the maximum power recovered by the battery in fault mode.

[0049] ③Total voltage limit power: (applicable to drive)

[0050] Under intense driving conditions, the total pressure of the battery pack will drop rapidly, which will cause the output power of the battery pack to drop rapidly. At this time, the total pressure needs to be segmented, and the available power is then linearly reduced as follows:

[0051]

[0052] Among them, V1 and V2 are the total voltage limit power segment calibration values, V 实时 It is the real-time total voltage value of the battery pack.

[0053] ④ Single unit power limit: (applicable to drive)

[0054] When the battery pack voltage drops to a certain threshold, the available power is:

[0055] P 故障限功率 =P 蠕行

[0056] It can be understood that the single-cell power limit is the same as the fault power limit.

[0057] Then, under the driving condition or the recovery condition, the minimum value of various power limit values ​​is obtained to obtain the available driving power or available recovery power for output.

[0058] In summary, the main design concept of the present invention lies in proposing a self-learning available power calculation strategy, which includes querying a preset power parameter table through a table lookup operation to obtain the current maximum available power and attenuation factor. The target available power for meter display is then corrected based on the attenuation factor in combination with the available power, a set correction period, and historical uncorrected power data. The present invention can autonomously adjust the available power value for display, unaffected by the power attenuation over the battery pack's lifespan, and is suitable for calculating available power throughout the life cycle of an electric vehicle.

[0059] In the embodiment of the present invention, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a, b and c, where a, b, c can be single or multiple.

[0060] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings, but the above is only a preferred embodiment of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred modes can be reasonably combined and matched into a variety of equivalent schemes by those skilled in the art without departing from or changing the design ideas and technical effects of the present invention; therefore, the scope of implementation of the present invention is not limited to what is shown in the drawings. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the scope of protection of the present invention.

Claims

1. A self-learning method for obtaining available power for electric vehicle instrument display, characterized in that: include: Querying a preset power parameter table through a table lookup operation to obtain the maximum available power and attenuation factor at the current moment, wherein the attenuation factor is related to the usage time of the battery pack; Correction is performed based on the attenuation factor in combination with the available power, a set correction period, and historical uncorrected power data to obtain a target available power for instrument display; Among them, the number of times the vehicle is at full power reaches a preset upper limit is set as the first number and serves as the correction period; and the historical uncorrected power data includes: the second number of times the difference between the actual power and the available power in the pre-stored uncorrected full power condition is greater than the preset power difference threshold.

2. The self-learning available power acquisition method for electric vehicle instrument display according to claim 1, characterized in that: The target available power for meter display is obtained by performing correction based on the attenuation factor in combination with the available power, the set correction period, and the historical uncorrected power data, and is calculated according to the following formula: Among them, P 可用 is the maximum available power at the current moment obtained by looking up the table, δ is the attenuation factor, is the first number, and M is the second number.

3. The self-learning available power acquisition method for electric vehicle instrument display according to claim 1, characterized in that: The method further includes: after reaching the correction period, determining a correction trigger condition based on the second number of times, or based on the first number of times and the second number of times.

4. The self-learning available power acquisition method for electric vehicle instrument display according to claim 3, characterized in that: Determining the modification trigger condition includes: When the second number exceeds a preset upper limit of the second number, it is determined that the correction trigger condition has been met; or, When the ratio of the second number of times to the first number of times is greater than a preset ratio value, it is determined that the correction trigger condition has been met.

5. The self-learning available power acquisition method for electric vehicle instrument display according to claim 4, characterized in that: The method further includes: when a correction recovery condition is reached, jumping the displayed available power back to the target available power after the previous correction, wherein the correction recovery condition is that the ratio of the second number to the first number is less than or equal to the preset ratio value.

Images