Current-based battery charging and discharging protection method, device, and electronic device

Abstract

The present invention provides a current-based battery charge and discharge protection method, device and electronic equipment, which relate to the technical field of battery protection, including: determining the discharge overcurrent threshold and feedback overcurrent threshold of the battery cell in the vehicle driving state based on the maximum allowable current of the battery cell in the battery pack, the current sampling error and the accuracy of the battery management system; determining the DC charging overcurrent threshold of the battery cell in the vehicle DC charging state based on the feedback current, continuous charging current and request current of the battery cell within a preset time; protecting the battery cell during the charging and discharging process based on the discharge overcurrent threshold, feedback overcurrent threshold and DC charging overcurrent threshold; and accurately determining the current thresholds of the vehicle driving state and charging state in combination with actual influencing factors, thereby alleviating the problem of low reliability of current battery charge and discharge safety evaluation.

Description

Technical Field

[0001] The present invention relates to the technical field of battery protection, and in particular to a battery charging and discharging protection method, device and electronic equipment based on voltage and temperature. Background Art

[0002] With the development of electric vehicle technology, people are paying more and more attention to the application safety of vehicle battery packs.

[0003] Currently, the safety of battery packs during the charging and discharging process is generally verified by pre-setting fixed thresholds for the corresponding battery pack parameters. However, the setting of these fixed thresholds has no logical basis and cannot be used as an indicator to determine whether the battery pack is safe during the charging and discharging process. In other words, the safety and reliability of today's battery packs during the charging and discharging process are not high. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a current-based battery charging and discharging protection method, device and electronic equipment, which, combined with actual influencing factors, accurately determine the current thresholds of the vehicle's driving state and charging state, thereby alleviating the problem of low reliability of current battery charging and discharging safety evaluation.

[0005] In a first aspect, an embodiment provides a current-based battery charge and discharge protection method, the method comprising:

[0006] Determine the discharge overcurrent threshold and feedback overcurrent threshold of the battery cell when the vehicle is in motion based on the maximum allowable current of the battery cell in the battery pack, the current sampling error, and the accuracy of the battery management system;

[0007] Determining a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on the feedback current, the continuous charging current, and the requested current of the battery cell within a preset time;

[0008] Based on the discharge overcurrent threshold, the feedback overcurrent threshold and the DC charge overcurrent threshold, the battery cell is protected during the charging and discharging process.

[0009] In an optional embodiment, the step of determining a discharge overcurrent threshold and a feedback overcurrent threshold of the battery cell when the vehicle is in motion, based on the maximum allowable current of the battery cell in the battery pack, the current sampling error, and the accuracy of the battery management system, includes:

[0010] Perform linear difference calculation based on the maximum allowable discharge current of the battery cells in the battery pack and the maximum allowable discharge current of the vehicle corresponding to each battery cell temperature to determine the minimum discharge current difference between the battery cell and the vehicle;

[0011] Based on the product of the minimum discharge current difference, the sampling accuracy of the battery management system and the current detection accuracy, the discharge overcurrent threshold of the battery cell in the vehicle driving state is determined.

[0012] In an optional embodiment, the step of determining the discharge overcurrent threshold and the feedback overcurrent threshold of the battery cell when the vehicle is in motion based on the maximum allowable current of the battery cell in the battery pack, the current sampling error, and the accuracy of the battery management system further includes:

[0013] Perform linear difference calculation based on the maximum allowable feedback current of the battery cells in the battery pack and the maximum allowable feedback current of the vehicle corresponding to each battery cell temperature to determine the minimum feedback current difference between the battery cells and the vehicle;

[0014] Based on the product of the minimum feedback current difference, the current sampling error and the current detection accuracy of the battery management system, a feedback overcurrent threshold of the battery cell in the vehicle driving state is determined.

[0015] In an optional embodiment, the step of determining a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on the feedback current, the continuous charging current, and the requested current of the battery cell within a preset time includes:

[0016] Dividing the feedback current of the battery cell within a first preset time by the continuous charging current to determine a first current ratio;

[0017] A first DC charging overcurrent threshold of the battery cell in a vehicle DC charging state is determined based on a product of the first current ratio and the requested current.

[0018] In an optional embodiment, the step of determining a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on the feedback current, the continuous charging current, and the requested current of the battery cell within a preset time further includes:

[0019] Dividing the feedback current of the battery cell within a second preset time by the continuous charging current to determine a second current ratio, wherein the second preset time is greater than the first preset time;

[0020] A second DC charging overcurrent threshold of the battery cell in a vehicle DC charging state is determined based on a product of the second current ratio and the requested current.

[0021] In an optional embodiment, the step of protecting the battery cell during the charging and discharging process based on the discharge overcurrent threshold, the feedback overcurrent threshold, and the DC charging overcurrent threshold includes:

[0022] If the discharge current of the battery cell when the vehicle is running is greater than the discharge overcurrent threshold, or the feedback current of the battery cell when the vehicle is running is greater than the feedback overcurrent threshold, the control relay is cut off.

[0023] In an optional embodiment, the step of protecting the battery cell during the charging and discharging process based on the discharge overcurrent threshold, the feedback overcurrent threshold, and the DC charging overcurrent threshold further includes:

[0024] If the charging current of the battery cell in the vehicle DC charging state is not less than the first DC charging overcurrent threshold, controlling the relay to cut off;

[0025] If the charging current of the battery cell in the vehicle DC charging state is greater than the second DC charging overcurrent threshold, the charging current is reduced by 50%.

[0026] In a second aspect, an embodiment provides a current-based battery charge and discharge protection device, the device comprising:

[0027] A first determination module determines a discharge overcurrent threshold and a feedback overcurrent threshold of the battery cell in a vehicle driving state based on a maximum allowable current of the battery cell in the battery pack, a current sampling error, and an accuracy of a battery management system;

[0028] A second determination module determines a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on a feedback current, a continuous charging current, and a requested current of the battery cell within a preset time;

[0029] The protection module protects the battery cell during the charging and discharging process based on the discharge overcurrent threshold, the feedback overcurrent threshold and the DC charging overcurrent threshold.

[0030] In a third aspect, an embodiment provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, the steps of the method described in any of the aforementioned embodiments are implemented.

[0031] In a fourth aspect, an embodiment provides a machine-readable storage medium, wherein the machine-readable storage medium stores machine-executable instructions. When the machine-executable instructions are called and executed by a processor, the machine-executable instructions prompt the processor to implement the steps of the method described in any one of the aforementioned implementation methods.

[0032] An embodiment of the present invention provides a current-based battery charge and discharge protection method, device, and electronic device. The method determines the overcurrent threshold value under the vehicle driving state and the vehicle DC charging state, and uses the determined precise threshold value as the evaluation standard for the battery charge and discharge reliability, thereby ensuring the safety of battery application. Among them, taking into account the impact on the overcurrent threshold value, the maximum allowable current, the current sampling error, and the accuracy of the battery management system are selected to determine a more accurate discharge overcurrent threshold and feedback current threshold under the vehicle driving state. At the same time, the feedback current, continuous charging current, and request current within a preset time are selected to determine a more accurate DC charging overcurrent threshold under the battery DC charging state. Under the action of the above thresholds, the accuracy of battery cell evaluation can be higher.

[0033] Other features and advantages of the present disclosure will be set forth in the following description, or some features and advantages may be inferred or unambiguously determined from the description, or may be learned by practicing the above-mentioned technology of the present disclosure.

[0034] In order to make the above-mentioned objectives, features and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A flow chart of a current-based battery charge and discharge protection method provided in an embodiment of the present invention;

[0037] Figure 2 A functional module diagram of a current-based battery charge and discharge protection device provided by an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of the hardware architecture of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0040] The current safety protection scheme for battery packs during the charging and discharging process is generally based on a preset parameter threshold to compare the actual collected value of the corresponding parameter during the battery pack charging and discharging process. If the actual collected value of the parameter reaches the parameter threshold, the control executes the corresponding battery pack protection measure. However, the parameter threshold used to verify battery safety is often pre-set by staff based on experience or according to the factory threshold. It is not adaptable to actual battery application scenarios and does not have a logical basis to ensure its verification reliability. Therefore, the reliability of the current battery pack charging and discharging safety protection scheme implemented based on the above method is not high, which in turn affects the user's driving safety.

[0041] Based on this, the embodiments of the present invention provide a current-based battery charging and discharging protection method, device, and electronic device, which, combined with actual influencing factors, accurately determine the current thresholds of the vehicle's driving status and charging status, thereby alleviating the problem of low reliability of current battery charging and discharging safety evaluation.

[0042] To facilitate understanding of this embodiment, a current-based battery charging and discharging protection method disclosed in an embodiment of the present invention is first introduced in detail. This method can be applied to vehicle-mounted control devices such as a battery management system BMS.

[0043] Figure 1 A flow chart of a current-based battery charge and discharge protection method provided in an embodiment of the present invention.

[0044] like Figure 1 As shown, the method includes the following steps:

[0045] Step S102 , determining a discharge overcurrent threshold and a feedback overcurrent threshold of the battery cells when the vehicle is in motion based on the maximum allowable current of the battery cells in the battery pack, the current sampling error, and the accuracy of the battery management system.

[0046] Each battery cell has a maximum allowable current value when it leaves the factory. Exceeding this maximum current value can cause overcharging, overdischarging, and other performance-damaging conditions. Current sampling error refers to the error in collecting the cell current. This error can be calculated based on the accuracy of the current sampling device or by pre-calculating the error from multiple cell current sampling runs. The accuracy of the battery management system (BMS) can be understood as the initial accuracy of its detection and sampling.

[0047] It should be noted that the inventors' research has found that the operating conditions that significantly impact the current safety of battery cell charging and discharging include both the vehicle's driving state and the vehicle's charging state. To protect battery cell safety and improve compatibility, the present invention sets current protection values based on both vehicle driving and DC charging. When the vehicle is in driving, both discharge overcurrent and feedback overcurrent must be considered to ensure safety.

[0048] Step S104 , determining a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on the feedback current, the continuous charging current, and the requested current of the battery cell within a preset time.

[0049] The feedback current here is generated when the vehicle is in the DC charging state. It is different from the feedback current generated when the vehicle is in motion in the previous steps. Different preset times correspond to different feedback currents. The preset time can be set in advance based on the actual application needs of the vehicle or battery cell. The continuous charging current is a charging indicator of the vehicle's DC charging state, which is known to those skilled in the art. The requested current can be understood as the charging current that can be displayed on the charging station.

[0050] Step S106 , protecting the battery cell during the charging and discharging process based on the discharge overcurrent threshold, the feedback overcurrent threshold, and the DC charging overcurrent threshold.

[0051] It can be understood that the discharge overcurrent threshold and feedback overcurrent threshold determined in the above steps are used to judge whether there is a discharge overcurrent and feedback overcurrent in the vehicle's driving state. On this basis, the DC charging overcurrent threshold obtained in the above steps is used to judge whether there is a charging overcurrent in the vehicle's DC charging state, and then corresponding protection measures can be taken for the battery cell.

[0052] In a preferred embodiment of actual application, the overcurrent thresholds under the vehicle driving state and the vehicle DC charging state are determined, and the determined precise thresholds are used as evaluation criteria for battery charging and discharging reliability, thereby ensuring the safety of battery application; wherein, taking into account the impact on the overcurrent threshold, the maximum allowable current, the current sampling error and the accuracy of the battery management system are selected to determine a more precise discharge overcurrent threshold and feedback current threshold under the vehicle driving state; at the same time, the feedback current, the continuous charging current and the request current within the preset time are selected to determine a more precise DC charging overcurrent threshold under the battery DC charging state, which can make the battery cell evaluation more accurate under the action of the above thresholds.

[0053] In some embodiments, the inventors have found that the discharge current in a vehicle driving state has a significant impact on the safety of the battery cell. Therefore, it is necessary to determine the discharge overcurrent threshold in this scenario. As an example, step S102 may include:

[0054] In step 1.1), a linear difference calculation is performed based on the maximum allowable discharge current of the battery cells in the battery pack and the maximum allowable discharge current of the vehicle corresponding to each battery cell temperature to determine the minimum discharge current difference between the battery cells and the vehicle.

[0055] Among them, the maximum allowable discharge current of each brand of battery cell may not be the same. Similarly, the maximum allowable discharge current of the whole vehicle at each battery cell temperature of different brands of vehicles is also different. For example, the maximum allowable discharge current of the whole vehicle corresponding to battery cell temperature A is a, the maximum allowable discharge current of the whole vehicle corresponding to battery cell temperature B is b, the maximum allowable discharge current of the whole vehicle corresponding to battery cell temperature C is c, and so on. The maximum allowable discharge current x of the battery cell is calculated by subtracting the maximum allowable discharge current of the whole vehicle corresponding to each battery cell temperature to obtain the discharge current difference corresponding to each battery cell temperature, and the minimum discharge current difference is determined therefrom, that is, MIN (maximum allowable discharge current of the battery cell - maximum allowable discharge current of the whole vehicle corresponding to different battery cell temperatures).

[0056] In step 1.2, a discharge overcurrent threshold of the battery cell when the vehicle is in motion is determined based on the product of the minimum discharge current difference, the sampling accuracy of the battery management system, and the current detection accuracy.

[0057] It can be understood that the discharge overcurrent threshold I1=MIN (the maximum allowable battery cell discharge current - the maximum allowable vehicle current corresponding to different battery cell temperatures) * BMS sampling accuracy * BMS current detection accuracy; among which, the BMS current detection accuracy can be ±0.5%.

[0058] In some embodiments, the inventors have found that the feedback current during vehicle driving also has a significant impact on the safety of the battery cell. Therefore, it is necessary to determine the feedback overcurrent threshold in this scenario. As an example, the above step S102 further includes:

[0059] In step 2.1), a linear difference calculation is performed based on the maximum allowable feedback current of the battery cells in the battery pack and the maximum allowable feedback current of the vehicle corresponding to each battery cell temperature to determine the minimum feedback current difference between the battery cell and the vehicle.

[0060] Here, the method of determining the minimum discharge current difference is similar to the method in the above step 1.1), and no further details are given here. The minimum feedback current difference between the battery cell and the whole vehicle can be obtained, that is, MIN (the maximum allowable battery cell feedback current - the maximum allowable vehicle feedback current corresponding to different battery cell temperatures).

[0061] In step 2.2, a feedback overcurrent threshold of the battery cell in a vehicle driving state is determined based on the product of the minimum feedback current difference, the current sampling error, and the current detection accuracy of the battery management system.

[0062] It can be understood that the feedback overcurrent threshold I2 = MIN (the maximum allowable battery cell feedback current - the maximum allowable vehicle feedback current corresponding to different battery cell temperatures) * current sampling error * BMS current detection accuracy.

[0063] In actual application, if the discharge current of the battery cell when the vehicle is in motion is greater than the discharge overcurrent threshold, or the feedback current of the battery cell when the vehicle is in motion is greater than the feedback overcurrent threshold, the control relay is cut off to achieve battery protection during the charging and discharging process.

[0064] Based on the above embodiment, the inventors have found through further research that, in addition to the significant influence of the current in the vehicle driving state on battery charging and discharging, the current in the vehicle DC charging state is also an important indicator that needs to be considered. Therefore, it is necessary to determine the current threshold in the vehicle DC charging state to ensure the reliability of the battery safety evaluation. As an example, step S104 in the above embodiment includes:

[0065] In step 3.1, the feedback current of the battery cell within the first preset time is divided by the continuous charging current to determine a first current ratio.

[0066] Among them, the first preset time can be selected as 10s, that is, the first current ratio is I_10s feedback / I_continuous charging. In actual applications, 200% is the minimum value of 10s feedback current / continuous charging current allowed by the battery cell. Therefore, the first current ratio is set to 200% to ensure that there is no risk of overcharging the battery cell.

[0067] Step 3.2) determining a first DC charging overcurrent threshold of the battery cell in a vehicle DC charging state based on a product of the first current ratio and the requested current.

[0068] It can be understood that the first DC charging overcurrent threshold I3 = (I_10s feedback / I_continuous charging)*requested current.

[0069] In some embodiments, the battery is protected and controlled based on the first DC charging overcurrent threshold. If the charging current of the battery cell during vehicle DC charging is not less than the first DC charging overcurrent threshold, the relay is controlled to disconnect. If the DC charging current detected by the BMS is ≥ 200% of the requested current, it indicates a serious abnormality in the charging pile current module, and the relay is directly disconnected.

[0070] In some embodiments, step S104 in the above embodiment further includes:

[0071] In step 4.1, the feedback current of the battery cell within the second preset time is divided by the continuous charging current to determine a second current ratio.

[0072] The second preset time is greater than the first preset time and can be 30 seconds. Thus, the second current ratio is I_30s feedback / I_continuous charging. In actual use, the minimum allowable value of the 30s feedback current / continuous charging current allowed by the battery cell is 143%. This minimum value of the second current ratio ensures that the battery cell will not be overcharged.

[0073] Step 4.2) determining a second DC charging overcurrent threshold of the battery cell in a vehicle DC charging state based on the product of the second current ratio and the requested current.

[0074] The second DC charging overcurrent threshold I4=(I_30s feedback / I_continuous charging)*requested current.

[0075] In some embodiments, according to step S106, it can be known which control strategy is used to protect the battery during the DC charging process of the vehicle:

[0076] In step 5.1, if the charging current of the battery cell in the vehicle DC charging state is greater than the second DC charging overcurrent threshold, the charging current is reduced by 50%.

[0077] If the DC charging current detected by the BMS is ≥ 143% of the requested current (<200%), the current will be reduced by 50%. At this time, the charging current value has not reached the maximum value of the fault range (<200%). By reducing the charging current by 50%, it can be ensured that it is within the requested current range, and there is no need to control the execution of the cut-off relay operation.

[0078] In an embodiment of the present invention, by respectively determining the overcurrent thresholds for the vehicle driving state and the vehicle DC charging state, the battery during the charging and discharging process can be protected according to a more accurate protection threshold that is more in line with the actual situation and has a logical basis, thereby improving the reliability of battery evaluation.

[0079] like Figure 2 As shown, an embodiment of the present invention further provides a current-based battery charge and discharge protection device 200, the device comprising:

[0080] A first determining module 201 determines a discharge overcurrent threshold and a feedback overcurrent threshold of a battery cell in a vehicle driving state based on a maximum allowable current of the battery cell in the battery pack, a current sampling error, and an accuracy of a battery management system;

[0081] A second determining module 202 determines a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on the feedback current, continuous charging current, and requested current of the battery cell within a preset time;

[0082] The protection module 203 protects the battery cell during the charging and discharging process based on the discharge overcurrent threshold, the feedback overcurrent threshold, and the DC charging overcurrent threshold.

[0083] In actual application, the first determination module is used to determine the overcurrent threshold of the vehicle's driving state, and the second determination module is used to determine the overcurrent threshold of the vehicle's DC charging state. The protection module protects the battery cells during the charging and discharging process based on the aforementioned determined overcurrent thresholds. Based on the precise determination of the current threshold, a highly reliable battery protection effect is achieved.

[0084] In some embodiments, the first determination module is further specifically used to perform linear difference calculation based on the maximum allowable discharge current of the battery cells in the battery pack and the maximum allowable discharge current of the entire vehicle corresponding to each battery cell temperature, to determine the minimum discharge current difference between the battery cells and the entire vehicle; based on the product of the minimum discharge current difference, the sampling accuracy of the battery management system, and the current detection accuracy, to determine the discharge overcurrent threshold of the battery cell when the vehicle is in driving state.

[0085] In some embodiments, the first determination module is further specifically used to perform linear difference calculation based on the maximum allowable feedback current of the battery cells in the battery pack and the maximum allowable feedback current of the entire vehicle corresponding to each battery cell temperature, to determine the minimum feedback current difference between the battery cell and the entire vehicle; based on the product of the minimum feedback current difference, the current sampling error and the current detection accuracy of the battery management system, to determine the feedback overcurrent threshold of the battery cell when the vehicle is in driving state.

[0086] In some embodiments, the second determination module is further specifically used to divide the feedback current of the battery cell within a first preset time by the continuous charging current to determine a first current ratio; and based on the product of the first current ratio and the requested current, determine the first DC charging overcurrent threshold of the battery cell in the vehicle DC charging state.

[0087] In some embodiments, the second determination module is further specifically used to divide the feedback current of the battery cell within a second preset time by the continuous charging current to determine a second current ratio, wherein the second preset time is greater than the first preset time; based on the product of the second current ratio and the requested current, determine the second DC charging overcurrent threshold of the battery cell in the vehicle DC charging state.

[0088] In some embodiments, the protection module is further specifically used to control the relay to cut off if the discharge current of the battery cell when the vehicle is in motion is greater than the discharge overcurrent threshold, or the feedback current of the battery cell when the vehicle is in motion is greater than the feedback overcurrent threshold.

[0089] In some embodiments, the protection module is further specifically used to control the relay to cut off if the charging current of the battery cell in the vehicle DC charging state is not less than the first DC charging overcurrent threshold; if the charging current of the battery cell in the vehicle DC charging state is greater than the second DC charging overcurrent threshold, reduce the charging current by fifty percent.

[0090] Figure 3 Schematic diagram of the hardware architecture of the electronic device 300 provided in an embodiment of the present invention. Figure 3 As shown, the electronic device 300 includes a machine-readable storage medium 301 and a processor 302. It may also include a non-volatile storage medium 303, a communication interface 304, and a bus 305. The machine-readable storage medium 301, the processor 302, the non-volatile storage medium 303, and the communication interface 304 communicate with each other via the bus 305. The processor 302 reads and executes the machine-executable instructions for current-based battery charge and discharge protection in the machine-readable storage medium 301 to perform the current-based battery charge and discharge protection method described in the above embodiment.

[0091] The machine-readable storage medium referred to herein can be any electronic, magnetic, optical, or other physical storage device that can contain or store information, such as executable instructions, data, and the like. For example, the machine-readable storage medium can be: RAM (Random Access Memory), volatile memory, non-volatile memory, flash memory, a storage drive (such as a hard drive), any type of storage disk (such as a CD, DVD, etc.), or similar storage media, or a combination thereof.

[0092] The non-volatile medium may be a non-volatile memory, a flash memory, a storage drive (such as a hard drive), any type of storage disk (such as an optical disk, a DVD, etc.), or similar non-volatile storage media, or a combination thereof.

[0093] It can be understood that the specific operation methods of each functional module in this embodiment can refer to the detailed description of the corresponding steps in the above method embodiment, and will not be repeated here.

[0094] The computer-readable storage medium provided in the embodiments of the present invention stores a computer program. When the computer program code is executed, the current-based battery charging and discharging protection method described in any of the above embodiments can be implemented. For specific implementation, please refer to the method embodiment and will not be repeated here.

[0095] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems and devices can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0096] In addition, in the description of the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0097] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0098] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-mentioned embodiments, ordinary technicians in this field should understand that any technician familiar with this technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention.

Claims

1. A current-based battery charge and discharge protection method, characterized in that: The method comprises: Perform linear difference calculation based on the maximum allowable discharge current of the battery cells in the battery pack and the maximum allowable discharge current of the vehicle corresponding to each battery cell temperature to determine the minimum discharge current difference between the battery cell and the vehicle; Determining a discharge overcurrent threshold of the battery cell when the vehicle is in motion based on the product of the minimum discharge current difference, a sampling accuracy of the battery management system, and a current detection accuracy; Perform linear difference calculation based on the maximum allowable feedback current of the battery cells in the battery pack and the maximum allowable feedback current of the vehicle corresponding to each battery cell temperature to determine the minimum feedback current difference between the battery cells and the vehicle; Determining a feedback overcurrent threshold of the battery cell when the vehicle is in motion based on a product of the minimum feedback current difference, a current sampling error, and a current detection accuracy of a battery management system; Determining a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on the feedback current, the continuous charging current, and the requested current of the battery cell within a preset time; Based on the discharge overcurrent threshold, the feedback overcurrent threshold and the DC charge overcurrent threshold, the battery cell is protected during the charging and discharging process.

2. The method according to claim 1, characterized in that The step of determining a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on a feedback current, a continuous charging current, and a requested current of the battery cell within a preset time includes: Dividing the feedback current of the battery cell within a first preset time by the continuous charging current to determine a first current ratio; A first DC charging overcurrent threshold of the battery cell in a vehicle DC charging state is determined based on a product of the first current ratio and the requested current.

3. The method according to claim 2, characterized in that The step of determining a DC charging overcurrent threshold of the battery cell in a DC charging state of the vehicle based on the feedback current, the continuous charging current, and the requested current of the battery cell within a preset time period further includes: Dividing the feedback current of the battery cell within a second preset time by the continuous charging current to determine a second current ratio, wherein the second preset time is greater than the first preset time; A second DC charging overcurrent threshold of the battery cell in a vehicle DC charging state is determined based on a product of the second current ratio and the requested current.

4. The method according to claim 2, characterized in that The step of protecting the battery cell during the charging and discharging process based on the discharge overcurrent threshold, the feedback overcurrent threshold, and the DC charging overcurrent threshold includes: If the discharge current of the battery cell when the vehicle is running is greater than the discharge overcurrent threshold, or the feedback current of the battery cell when the vehicle is running is greater than the feedback overcurrent threshold, the control relay is cut off.

5. The method according to claim 3, characterized in that The step of protecting the battery cell during the charging and discharging process based on the discharge overcurrent threshold, the feedback overcurrent threshold, and the DC charging overcurrent threshold further includes: If the charging current of the battery cell in the vehicle DC charging state is not less than the first DC charging overcurrent threshold, controlling the relay to cut off; If the charging current of the battery cell in the vehicle DC charging state is greater than the second DC charging overcurrent threshold, the charging current is reduced by 50%.

6. A battery charge and discharge protection device based on current, characterized in that: The device comprises: The first determination module performs a linear difference calculation based on the maximum allowable discharge current of the battery cells in the battery pack and the maximum allowable discharge current of the whole vehicle corresponding to each battery cell temperature, and determines the minimum discharge current difference between the battery cells and the whole vehicle; determines the discharge overcurrent threshold of the battery cells when the vehicle is in motion based on the product of the minimum discharge current difference, the sampling accuracy of the battery management system, and the current detection accuracy; performs a linear difference calculation based on the maximum allowable feedback current of the battery cells in the battery pack and the maximum allowable feedback current of the whole vehicle corresponding to each battery cell temperature, and determines the minimum feedback current difference between the battery cells and the whole vehicle; determines the feedback overcurrent threshold of the battery cells when the vehicle is in motion based on the product of the minimum feedback current difference, the current sampling error, and the current detection accuracy of the battery management system; the second determination module determines the DC charging overcurrent threshold of the battery cells when the vehicle is in motion based on the feedback current, continuous charging current, and request current of the battery cells within a preset time; The protection module protects the battery cell during the charging and discharging process based on the discharge overcurrent threshold, the feedback overcurrent threshold and the DC charging overcurrent threshold.

7. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A machine-readable storage medium, characterized in that The machine-readable storage medium stores machine-executable instructions. When the machine-executable instructions are called and executed by a processor, the machine-executable instructions prompt the processor to implement the steps of the method according to any one of claims 1 to 5.

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