A method and device for pre-under voltage power control of a power battery system

Abstract

The application discloses a kind of power battery system pre-under voltage power control method and device, it is related to electric vehicle technical field, comprising: the current SOC value of obtaining power battery system;The lowest temperature of single body and the minimum single body voltage value in power battery system are obtained;Based on the lowest temperature of single body and the current SOC value, the allowed instantaneous discharge power of power battery system is determined;Based on the lowest temperature of single body and the minimum single body voltage value, the allowed instantaneous discharge power is corrected, and the target discharge power of power battery system is obtained.The application is based on the lowest temperature of single body and the minimum single body voltage value, and the allowed instantaneous discharge power is corrected, and then the discharge power of power battery system is controlled, battery can be prevented to appear over-discharge problem, and user safety driving experience is improved.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle technology, specifically to a method and apparatus for controlling pre-undervoltage power in a power battery system. Background Technology

[0002] Compared to traditional cars, electric vehicles are widely favored due to their lower environmental impact. As one of the most crucial components of an electric vehicle, protecting the power battery during vehicle operation is paramount. Without undervoltage protection for the minimum individual cell voltage, over-discharge can occur, causing irreversible damage to the battery pack. This can also lead to breakdowns during driving, impacting the user's driving experience and safety. Summary of the Invention

[0003] The purpose of this invention is to provide a method and apparatus for controlling the pre-undervoltage power of a power battery system in order to solve at least one of the above-mentioned technical problems.

[0004] In a first aspect, embodiments of the present invention provide a pre-undervoltage power control method for a power battery system, applied to the battery management system of the power battery system; comprising: obtaining the current SOC value of the power battery system; obtaining the minimum temperature and minimum voltage value of a single cell in the power battery system; determining the allowable instantaneous discharge power of the power battery system based on the minimum temperature and the current SOC value; and correcting the allowable instantaneous discharge power based on the minimum temperature and the minimum voltage value of the single cell to obtain the target discharge power of the power battery system.

[0005] Further, based on the lowest temperature of the single cell and the current SOC value, the allowable instantaneous discharge power of the power battery system is determined, including: based on a preset discharge power table, finding the discharge power corresponding to the lowest temperature of the single cell and the current SOC value, to obtain the allowable instantaneous discharge power of the power battery system.

[0006] Further, based on the lowest temperature of the single cell and the minimum single cell voltage value, the allowable instantaneous discharge power is corrected to obtain the target discharge power of the power battery system, including: determining the target temperature range in which the lowest temperature of the single cell is located; determining whether the minimum single cell voltage value is less than or equal to the pre-undervoltage setting voltage value corresponding to the target temperature range; if so, the allowable instantaneous discharge power is corrected to obtain the target discharge power.

[0007] Further, the target temperature range includes: a first temperature range, a second temperature range, and a third temperature range, corresponding to a first pre-undervoltage setting voltage value, a second pre-undervoltage setting voltage value, and a third pre-undervoltage setting voltage value, respectively; determining whether the minimum single-cell voltage value is less than or equal to the pre-undervoltage setting voltage value corresponding to the target temperature range includes: if the lowest single-cell temperature is within the first temperature range, then determining whether the minimum single-cell voltage value is less than or equal to the first pre-undervoltage setting voltage value; if the lowest single-cell temperature is within the second temperature range, then determining whether the minimum single-cell voltage value is less than or equal to the second pre-undervoltage setting voltage value; if the lowest single-cell temperature is within the third temperature range, then determining whether the minimum single-cell voltage value is less than or equal to the third pre-undervoltage setting voltage value.

[0008] Furthermore, the target discharge power is the maximum value between the target calculated power value and the preset limit power value; the target calculated power value is the product of the allowable instantaneous discharge power and the preset correction coefficient.

[0009] Secondly, embodiments of the present invention also provide a pre-undervoltage power control device for a power battery system, applied to the battery management system of a power battery system; comprising: a first acquisition module, a second acquisition module, a determination module, and a correction module; wherein, the first acquisition module is used to acquire the current SOC value of the power battery system; the second acquisition module is used to acquire the minimum temperature and minimum voltage value of a single cell in the power battery system; the determination module is used to determine the allowable instantaneous discharge power of the power battery system based on the minimum temperature of the single cell and the current SOC value; the correction module is used to correct the allowable instantaneous discharge power based on the minimum temperature of the single cell and the minimum voltage value of the single cell to obtain the target discharge power of the power battery system.

[0010] Furthermore, the determining module is also used to: find the discharge power corresponding to the lowest temperature of the single cell and the current SOC value based on a preset discharge power table, and obtain the allowable instantaneous discharge power of the power battery system.

[0011] Furthermore, the correction module further includes a determining unit and a judging unit; wherein, the determining unit is used to determine the target temperature range in which the lowest temperature of the single cell is located; the judging unit is used to judge whether the minimum single cell voltage value is less than or equal to the pre-undervoltage setting voltage value corresponding to the target temperature range; if so, the allowable instantaneous discharge power is corrected to obtain the target discharge power.

[0012] Further, the target temperature range includes: a first temperature range, a second temperature range, and a third temperature range, corresponding to the first pre-undervoltage setting voltage value, the second pre-undervoltage setting voltage value, and the third pre-undervoltage setting voltage value, respectively; the judgment unit is further configured to: if the lowest temperature of the single cell is within the first temperature range, determine whether the minimum single cell voltage value is less than or equal to the first pre-undervoltage setting voltage value; if the lowest temperature of the single cell is within the second temperature range, determine whether the minimum single cell voltage value is less than or equal to the second pre-undervoltage setting voltage value; if the lowest temperature of the single cell is within the third temperature range, determine whether the minimum single cell voltage value is less than or equal to the third pre-undervoltage setting voltage value.

[0013] Furthermore, the target discharge power is the maximum value between the target calculated power value and the preset limit power value; the target calculated power value is the product of the allowable instantaneous discharge power and the preset correction coefficient.

[0014] This invention provides a method and apparatus for controlling the pre-undervoltage power of a power battery system. Based on the lowest temperature and minimum voltage of a single cell, the allowable instantaneous discharge power is corrected, thereby controlling the discharge power of the power battery system. This can prevent over-discharge of the battery and improve the user's safe driving experience. Attached Figure Description

[0015] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0016] Figure 1 A flowchart of a pre-undervoltage power control method for a power battery system provided in an embodiment of the present invention;

[0017] Figure 2 A schematic diagram of a pre-undervoltage power control device for a power battery system provided in an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of a correction module provided in an embodiment of the present invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0020] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0021] Example 1

[0022] Figure 1 This is a flowchart of a pre-undervoltage power control method for a power battery system according to an embodiment of the present invention. This method is applied to the battery management system (BMS) of a power battery system. Figure 1 As shown, the method specifically includes the following steps:

[0023] Step S102: Obtain the current SOC value of the power battery system.

[0024] Specifically, the current state of charge (SOC) value of the power battery system is obtained through the Battery Control Unit (BCU).

[0025] Step S104: Obtain the lowest temperature and minimum voltage of a single cell in the power battery system.

[0026] Specifically, the lowest temperature of a single cell in the power battery system is obtained through a temperature sensor, and the minimum voltage value of a single cell in the power battery system is obtained through a Battery Monitor Unit (BMU).

[0027] Step S106: Determine the allowable instantaneous discharge power of the power battery system based on the lowest temperature of the individual cells and the current SOC value.

[0028] Preferably, in this embodiment of the invention, based on a preset discharge power table, the discharge power corresponding to the lowest temperature of a single cell and the current SOC value is found to obtain the allowable instantaneous discharge power of the power battery system.

[0029] Step S108: Based on the lowest temperature and minimum voltage of a single cell, the allowable instantaneous discharge power is corrected to obtain the target discharge power of the power battery system.

[0030] Specifically, step S108 also includes the following steps:

[0031] Step S1081: Determine the target temperature range where the lowest temperature of the monomer is located;

[0032] Step S1082: Determine whether the minimum single-cell voltage value is less than or equal to the pre-undervoltage setting voltage value corresponding to the target temperature range; if so, correct the allowable instantaneous discharge power to obtain the target discharge power.

[0033] In some optional embodiments provided by the present invention, the target temperature range includes: a first temperature range, a second temperature range, and a third temperature range, respectively corresponding to the first pre-undervoltage setting voltage value, the second pre-undervoltage setting voltage value, and the third pre-undervoltage setting voltage value. Step S1082 specifically includes:

[0034] If the lowest temperature of a single cell is within the first temperature range, then determine whether the minimum single cell voltage value is less than or equal to the first pre-undervoltage setting voltage value.

[0035] If the lowest temperature of a single cell is within the second temperature range, then determine whether the minimum single cell voltage value is less than or equal to the second pre-undervoltage setting voltage value.

[0036] If the lowest temperature of a single cell is within the third temperature range, then determine whether the minimum single cell voltage value is less than or equal to the third pre-undervoltage setting voltage value.

[0037] In some optional embodiments provided by the present invention, the target discharge power is the maximum value between the target calculated power value and the preset limit power value; the target calculated power value is the product of the allowable instantaneous discharge power and the preset correction coefficient.

[0038] As described above, the present invention provides a pre-undervoltage power control method for a power battery system. By comparing the minimum single-cell voltage value with the pre-undervoltage setting voltage value, it is determined whether pre-undervoltage protection should be performed, thereby controlling the discharge power of the power battery system. This can prevent over-discharge of the battery and improve the user's safe driving experience.

[0039] Example 2

[0040] This invention also provides another method for controlling the pre-undervoltage power of a power battery system, which specifically includes the following steps:

[0041] (1) During BMS system initialization, the current SOC value is read;

[0042] (2) The allowable instantaneous discharge power is obtained by looking up the discharge power table based on the lowest temperature of the cell and the current SOC value;

[0043] (3) Comparison of minimum unit voltage value and pre-undervoltage setting voltage value; trigger correction is divided into three intervals:

[0044] (a) When the minimum cell temperature T > a℃, the first pre-undervoltage setting voltage value = AmV; when the minimum cell voltage value ≤ the first pre-undervoltage setting voltage value: the discharge power is limited to Max (Y%||Z kW of the current table lookup value);

[0045] (b) When the minimum cell temperature b℃<T≤a℃, the second pre-undervoltage setting voltage value=B mV; when the minimum cell voltage value≤the second pre-undervoltage setting voltage value: the discharge power is limited to Max(Y%||Z kW of the current table lookup value);

[0046] (c) When the minimum cell temperature T ≤ b℃, the third pre-undervoltage setting voltage value = C mV; when the minimum cell voltage value ≤ the third pre-undervoltage setting voltage value: the discharge power is limited to Max (Y%||Z kW of the current table lookup value);

[0047] (4) Clear and re-evaluate after the BMS is powered on or off.

[0048] Where Y% is the preset correction coefficient, Z kW is the preset power limit value, and a and b are different temperature values.

[0049] For example, the lowest temperature of a single cell is 11℃, the rated SOC is 23% under vehicle discharge conditions, and the lowest rated single cell voltage is 3000mV for 1 second.

[0050] According to the discharge power table, the allowable instantaneous discharge power is 33kW.

[0051] Correction to allowable instantaneous discharge power: 33*Y%=0.33Y kW;

[0052] Therefore, the power is limited to 0.33Y kW.

[0053] Example 3

[0054] Figure 2 This is a schematic diagram of a pre-undervoltage power control device for a power battery system according to an embodiment of the present invention, applied to the battery management system of a power battery system. Figure 2 As shown, the device includes: a first acquisition module 10, a second acquisition module 20, a determination module 30, and a correction module 40.

[0055] Specifically, the first acquisition module 10 is used to acquire the current SOC value of the power battery system.

[0056] The second acquisition module 20 is used to acquire the lowest temperature and minimum voltage of a single cell in the power battery system.

[0057] The determination module 30 is used to determine the allowable instantaneous discharge power of the power battery system based on the lowest temperature of the individual cells and the current SOC value.

[0058] Preferably, the determining module 30 is further configured to: find the discharge power corresponding to the lowest temperature of a single cell and the current SOC value based on a preset discharge power table, and obtain the allowable instantaneous discharge power of the power battery system.

[0059] The correction module 40 is used to correct the allowable instantaneous discharge power based on the lowest temperature and minimum voltage of the single cell to obtain the target discharge power of the power battery system.

[0060] Optionally, the target discharge power is the maximum value between the target calculated power value and the preset limit power value; the target calculated power value is the product of the allowable instantaneous discharge power and the preset correction coefficient.

[0061] Figure 3 This is a schematic diagram of a correction module provided according to an embodiment of the present invention. Figure 3 As shown, the correction module 40 also includes a determination unit 41 and a judgment unit 42.

[0062] Specifically, the determining unit 41 is used to determine the target temperature range where the lowest temperature of the monomer is located;

[0063] The judgment unit 42 is used to determine whether the minimum single-cell voltage value is less than or equal to the pre-undervoltage setting voltage value corresponding to the target temperature range; if so, the allowable instantaneous discharge power is corrected to obtain the target discharge power.

[0064] In some optional embodiments provided by the present invention, the target temperature range includes: a first temperature range, a second temperature range, and a third temperature range, respectively corresponding to the first pre-undervoltage setting voltage value, the second pre-undervoltage setting voltage value, and the third pre-undervoltage setting voltage value; the determination unit 42 is further configured to:

[0065] If the lowest temperature of a single cell is within the first temperature range, then determine whether the minimum single cell voltage value is less than or equal to the first pre-undervoltage setting voltage value.

[0066] If the lowest temperature of a single cell is within the second temperature range, then determine whether the minimum single cell voltage value is less than or equal to the second pre-undervoltage setting voltage value.

[0067] If the lowest temperature of a single cell is within the third temperature range, then determine whether the minimum single cell voltage value is less than or equal to the third pre-undervoltage setting voltage value.

[0068] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

[0069] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0070] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0071] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0072] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A pre-undervoltage power control device for a power battery system, characterized in that, A battery management system applied to power battery systems; comprising: a first acquisition module, a second acquisition module, a determination module, and a correction module; wherein... The first acquisition module is used to acquire the current SOC value of the power battery system; The second acquisition module is used to acquire the lowest temperature and lowest voltage value of a single cell in the power battery system. The determining module is used to determine the allowable instantaneous discharge power of the power battery system based on the lowest temperature of the single cell and the current SOC value. The correction module is used to correct the allowable instantaneous discharge power based on the lowest temperature of the single cell and the minimum single cell voltage value, so as to obtain the target discharge power of the power battery system. The determining module is further configured to: find the discharge power corresponding to the lowest temperature of the single cell and the current SOC value based on a preset discharge power table, and obtain the allowable instantaneous discharge power of the power battery system; The target discharge power is the maximum value between the target calculated power value and the preset limit power value; the target calculated power value is the product of the allowable instantaneous discharge power and the preset correction coefficient.

2. The apparatus according to claim 1, characterized in that, The correction module further includes a determining unit and a judging unit; wherein, The determining unit is used to determine the target temperature range in which the lowest temperature of the monomer is located; The judgment unit is used to determine whether the minimum single-cell voltage value is less than or equal to the pre-undervoltage setting voltage value corresponding to the target temperature range; if so, the allowable instantaneous discharge power is corrected to obtain the target discharge power.

3. The apparatus according to claim 2, characterized in that, The target temperature range includes: a first temperature range, a second temperature range, and a third temperature range, corresponding to the first pre-undervoltage setting voltage value, the second pre-undervoltage setting voltage value, and the third pre-undervoltage setting voltage value, respectively; the judgment unit is further configured to: If the lowest temperature of the single cell is within the first temperature range, then determine whether the minimum single cell voltage value is less than or equal to the first pre-undervoltage setting voltage value. If the lowest temperature of the single cell is within the second temperature range, then determine whether the minimum single cell voltage value is less than or equal to the second pre-undervoltage setting voltage value; If the lowest temperature of the single cell is within the third temperature range, then determine whether the minimum single cell voltage value is less than or equal to the third pre-undervoltage setting voltage value.

4. A control method for a pre-undervoltage power control device for a power battery system according to any one of claims 1 to 3, characterized in that, Battery management systems applied to power battery systems; including: Obtain the current SOC value of the power battery system; Obtain the lowest temperature and lowest voltage value of a single cell in the power battery system; Based on the lowest temperature of the single cell and the current SOC value, the allowable instantaneous discharge power of the power battery system is determined; Based on the lowest temperature of the single cell and the minimum single cell voltage, the allowable instantaneous discharge power is corrected to obtain the target discharge power of the power battery system.

5. The control method according to claim 4, characterized in that, Based on the lowest temperature of the individual cell and the current SOC value, the allowable instantaneous discharge power of the power battery system is determined, including: Based on a preset discharge power table, the discharge power corresponding to the lowest temperature of the single cell and the current SOC value is found to obtain the allowable instantaneous discharge power of the power battery system.

6. The control method according to claim 4, characterized in that, Based on the lowest temperature and the lowest voltage of the individual cells, the allowable instantaneous discharge power is corrected to obtain the target discharge power of the power battery system, including: Determine the target temperature range in which the lowest temperature of the monomer is located; Determine whether the minimum single-unit voltage value is less than or equal to the pre-undervoltage setting voltage value corresponding to the target temperature range; If so, the allowable instantaneous discharge power is corrected to obtain the target discharge power.

7. The control method according to claim 6, characterized in that, The target temperature range includes: a first temperature range, a second temperature range, and a third temperature range, corresponding to the first pre-undervoltage setting voltage value, the second pre-undervoltage setting voltage value, and the third pre-undervoltage setting voltage value, respectively; determining whether the minimum single-cell voltage value is less than or equal to the pre-undervoltage setting voltage value corresponding to the target temperature range includes: If the lowest temperature of the single cell is within the first temperature range, then determine whether the minimum single cell voltage value is less than or equal to the first pre-undervoltage setting voltage value. If the lowest temperature of the single cell is within the second temperature range, then determine whether the minimum single cell voltage value is less than or equal to the second pre-undervoltage setting voltage value; If the lowest temperature of the single cell is within the third temperature range, then determine whether the minimum single cell voltage value is less than or equal to the third pre-undervoltage setting voltage value.

8. The control method according to claim 4, characterized in that, The target discharge power is the maximum value between the target calculated power value and the preset limit power value; the target calculated power value is the product of the allowable instantaneous discharge power and the preset correction coefficient.

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